Thoughts on My Diet

In my previous post, I covered the topic of nutrition requirements over a person's lifespan.  This brings to mind my own nutritional requirements beginning today and ending at a time yet to be determined.  Indeed, my newly acquired nutritional knowledge has made me reflect on my own dietary habits many times over the past several weeks.  Although I have already made minor adjustments to my diet, as I have learned nutritional concepts, it has also become clear that I must embark on an effort to seriously the strengths and weaknesses of my current diet and how I can modify my behaviors to increase the likelihood of long-term health.  In this post, I will analyze my own nutritional strengths and weaknesses, as well as identify the changes necessary to improve my own health and meet the USDA dietary guidelines.

Strengths

While I do not consider myself the epitome of health, there are many things that I am doing right.  Coming from a family that has a high incidence of cardiovascular disease (CVD), obesity, and diabetes, I have maintained a reasonable weight of 173 pounds.  Medical professionals use the Body Mass Index (BMI), a ratio between height and weight, to roughly ascertain if someone's weight is within a healthy range.  Generally speaking, a BMI of 18.5 to 24.9 is considered normal weight.  BMI doesn't tell the whole story, however, as the amount and location of body fat is also a necessary consideration when determining healthy weight.  In particular, visceral fat, or fat deep within the abdominal cavity, is associated with elevated risk for health issues (Sizer & Whitney, 2013).

With my height of 5 feet, 11 inches, my calculated BMI is 24.1.  Although this is near the top of the range for normal weight on the BMI scale, my waist size is only 33 inches, well below the 40 inch threshold for elevated risk due to visceral fat.  Therefore, I am considered to be of a healthy weight.  While not particularly athletic, I am relatively strong and participate in some physical activities each week.  From a dietary perspective, I eat chicken and fish several times per week and have cut back substantially on fattening and sugary foods, which is important for maintaining good health (Sizer & Whitney, 2013).

Weaknesses

I have been fortunate to have had good metabolism throughout my life, allowing me to eat large quantities of food without directly seeing the consequences.  However, as I have aged, I am no longer as immune to poor dietary choices as I used to be.  I can easily gain several pounds in a short amount of time, due to eating poorly.  Further, my family has high incidence of CVD, poor circulation, hypertension, obesity, and diabetes.  In other words, the genetic odds are stacked against me, in terms of potential for development of chronic disease.  Until taking this class, I have had only superficial knowledge of how refined sugar and saturated fats affect the body and the mechanisms by which they cause harm.  Despite my family history and lack of nutritional knowledge, I have historically followed very poor eating habits, particularly with portion control and the consumption of excess sugars and fats.  As a result, my intake of calories, saturated fats, and sugars are beyond dietary guidelines.

Research has shown that excess fat in body tissues hinder the effectiveness of insulin, resulting in diminished uptakes of blood sugar into the tissues.  As blood glucose levels rise, the development of Type-2 diabetes may result, leading to a wide variety of health risks, such as higher likelihood of death, blood glucose instability, risk of diabetic coma, neuropathy, and loss of limbs (Mayo Clinic, 2013).  Moreover, being overweight, and particularly obese, is associated to much higher risk of other chronic diseases, including CVD, gallbladder stones, and cancer (Sizer & Whitney, 2013).  The amount of time I spend on the computer each day, both for work and school, has made it difficult for me to participate in sustained physical activity on a regular basis.  Consequently, I do not get enough exercise.  Too maintain optimal health, it is recommended to exercise at least five days per week at 30 minutes per session (Sizer & Whitney, 2013).

Modification Plan

It is clear that I am headed down a risky path, if I continue to make the same dietary and physical activity choices that I have in the past.  To increase the likelihood that I will live a long and joyful life, I must make changes in my diet and get more physical exercise.  From a physical exercise standpoint, I will begin to chart my daily activities to understand precisely how much time I really am spending on exercise.  Currently, this is simply a wild guess, although I know it is not enough.  Once I have a better understand of actual values, I will know how much adjustment needs to be made.  That said, it is hard to imagine getting too much exercise, so perhaps charting my current activities provides little value.

My strategy for ensuring I get enough exercise is to begin cycling for at least 30 minutes each day during the fall, winter, and spring seasons.  This is particularly doable in the mild Arizona weather during those seasons.  When it is much hotter during the summer, I will swim laps in the pool every day.  I also wish to build up my lean tissue and muscle mass, so I will be purchasing some weights and begin strength-training.  During this time, I will ensure I have sufficient iron and protein intakes, which are essential for muscle development (Sizer & Whitney, 2013).

From a dietary standpoint, my primary focus is to create and follow a diet geared for diabetics.  Although I am not yet diabetic, I have been diagnosed as prediabetic, with a rising A1C blood sugar level.  Focusing on a diabetic diet will allow me to cut back on fat and sugar intakes.  Reducing sugar intakes will have a short term effect of lowering 3-month average blood sugar levels, while reducing fat intakes can improve efficacy of insulin in maintaining blood sugar levels.

Following a healthy diabetic diet consists of smaller portion sizes and eating balanced meals of foods with high-nutrient density, such as fruits and vegetables.  It also means to eat more fish and fiber, while cutting back on saturated fats, such as that found in red meats and baked goods.  Consumption of saturated fats should be no more than 7 percent of daily calories (Mayo Clinic, 2013).

Through the use of dietary planning tools, it will also be much easier to determine the proper quantities of foods to consume each day.  There are many graphical aids available online, which can be helpful in this process.  I will evaluate several diabetic food charts and choose one that works well for me.  An example of a daily diabetic food chart is illustrated below.

Food List for Diabetes (Gray, 2009).

Finally, I will regularly measure my weight and BMI, to ensure that I am headed in the right direction with my health.  The increased exercise will assist in heightening my metabolism and provide me with more energy.  Because my doctor has already scheduled A1C checkups with me, this will provide feedback as to whether I am achieving my goals of lessening my risk of diabetes and other chronic diseases.

Conclusion

Although I have been lucky in health thus far, despite my poor dietary choices, I cannot expect my luck to last forever.  It is crucial that I begin to take steps now to stack the cards in my favor and increase the likelihood that I will be here for many years to come.  I owe it to my loved ones and myself to make every effort to live a long and joyful life.  By making wiser choices in diet and physical activities, I can make a positive change in direction.

References

Gray, A. (2009). Medical Nutritional Therapy for the Patient With Diabetes . Retrieved from DiabetesManager: http://diabetesmanager.pbworks.com/w/page/17680273/Medical%20Nutritional%20Therapy%20for%20the%20Patient%20With%20Diabetes

Mayo Clinic. (2013). Diabetes Diet: Create Your Healthy-Eating Plan. Retrieved from Mayo Clinic: http://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-diet/art-20044295

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

Nutrition Requirements Across a Lifespan

In my last post, I discussed the role diet played in the prevention of underweight, overweight, and obesity.  Clearly, it is important that individuals maintain a healthy weight throughout their lives, but what constitutes a healthy weight is not always constant for a person of a given age.  Perhaps more importantly, the nutrient requirements vary substantially as a person progresses through his or her lifespan and experiences certain life events.  In this post, we will discuss and compare the nutritional requirements from pregnancy to childhood, and from adolescence to adulthood.

Pregnancy

Nutrition is critically important in the times leading up to pregnancy, during pregnancy, and afterward.  Although most nutritional aspects of pregnancy and early childhood relate to the mother, fathers preparing to have a child should also practice good nutrition, for it has been shown that low consumption of fruits and vegetables can have adverse affects on fertility of themselves and their children.  Moreover, excessive consumption of alcohol during the weeks prior to conception can damage the sperm's genetic makeup.  Even ignoring these aspects, it is easy to see that a healthy father will be better able to attend to his child's demanding needs after he or she is born (Sizer & Whitney, 2013).

From the very beginning, women who may become pregnant should make every effort to be of sufficient weight.  Underweight mothers have a high risk of giving birth to a low birthweight baby, which weighs less than 5.5 pounds.  Low birthweight babies are nearly 40 times more likely to die within the first year than those that are of normal weight.  Even if the baby does survive, the adaptations it makes to accommodate for the lack of nutritional resources increase its risk for developing obesity later on, affect its IQ and educational capabilities, and cause brain and growth impairments.  Similarly, obese mothers are highly encouraged to achieve a normal weight or there babies will have an increased risk of being born overweight or obese.  High birthweight babies have an increased risk of death, heart defects, neural tube defects, and birth trauma.  Further, obese mothers are more likely to experience complications during and after birth, including hypertension, infection, and gestational diabetes (Sizer & Whitney, 2013).  Thus, the importance of maintaining a healthy body weight before and throughout pregnancy cannot be overstated.

Nutrition is also important before pregnancy in order to ensure that her uterus will be able to support the development of the placenta, which acts as the conduit for supplying all the necessary components for life to the baby, as well as removing its waste products.  Because of the critical nature of the placenta, it must form properly, as there is no other mechanism for the baby to receive sustenance.  The development of the placenta is critically dependent on the mother's nutritional state and failure to develop properly can have longstanding consequences to the child and its children.  In addition, women that are expecting to get pregnant should ensure they have adequate intakes of folate and Vitamin B12.  Folate is particularly important as it plays a crucial role in the development and closure of the neural tube, which later forms the brain and spinal cord.  Because the critical period for formation and closure of the neural tube occurs very early, it is often already over by the time a woman suspects she is pregnant.  Therefore, sufficient folate intakes are needed in anticipation of becoming pregnant (Sizer & Whitney, 2013).

During the last 7 months of pregnancy, the fetus grows 50 times heavier and 20 times longer.  Over this period, cells are dividing at a rapid rate in order to form the baby's organs and other tissues.  To accommodate this, the mother's body also responds by strengthening muscles to support additional weight of the baby and increasing blood volume by 50 percent.  The 40 week spans of pregnancy is divided into thirds, called trimesters.  As the baby grows, there are important places in time, known as critical periods.  During critical periods, organs are developed at precise times throughout the gestation period.  As such, it is vital that the mother be able to supply the nutrients required at the right times.  Any malnutrition experienced during critical periods will result in adverse consequences to the organs that were developing at that time and can have long-lasting effects in such areas as dental health, susceptibility to infections, and risk of cardiovascular disease (Sizer & Whitney, 2013).

Increased needs for energy are also demanded during the second and third trimesters, so additional calories must be taken in to accommodate the growth of additional maternal tissue, the fetus, and placenta.  Additional intakes of iron are also needed, especially during the second half of pregnancy.  To avoid anemia, pregnant mothers should take dietary supplements of iron.  Alcohol intake should also be avoided, as it can result in birth defects, alcoholic mother syndrome, miscarriage, and low birthweight (Rumanaz Shahid & Alam, 2012).

The production of breast milk requires special dietary considerations.  Normally, breast milk contains all of the nourishment that a baby needs.  If a mother has decided to breastfeed, she must ensure that her nutrient intakes are sufficient to cover her own needs, as well as those of her baby.  Her body will do what it can to provide the required nutrients to the child, including depriving the mother of them when there is not enough for both people.  In addition, the actual production of breast milk consumes a fair amount of energy, approximately 500 calories per day.  Further, a substantial portion of breast milk is water.  Thus, breastfeeding women should ensure their nutrient intakes are sufficient to support themselves and their baby, consume an extra 330 calories each day, and drink plenty of water.  The additional 170 calories per day can be taken from the fat reserves that were gained during pregnancy (Sizer & Whitney, 2013).

Childhood

As a child begins its early life outside the womb, its body grows at a tremendous rate, with its weight doubling in the first 5 months and tripling by 12 months.  The baby also grows approximately 10 inches in the first year.  Growth slows substantially during the second year, but still at a rapid pace.  Pound for pound, an infant's metabolic rate is twice that of an adult.  Because of the high metabolism and growth, an infant must have sufficient supplies of the energy-yielding nutrients, as well as the vitamins and minerals that support growth, including calcium and vitamins A and D.  Since their metabolism is twice that of an adult's and they are growing rapidly, their intake requirements are over twice those of an adult, relative to body weight.  For instance, an infant requires approximately 100 calories per day per kilogram of weight, whereas an adult only requires 40.  Other nutrient requirements follow similar ratios, with some being substantially more.  Also, a baby's ratio of water to body weight is higher than that of an adult.  Although breast milk generally supplies sufficient quantities of water, mothers should be aware of the possibility of dehydration and provide additional water when needed (Sizer & Whitney, 2013).

Although baby formula can provide the nutrients an infant requires, research has shown that breast milk is superior in a number of areas.  Not only does it provide sufficient quantities of nearly all the essential nutrients, but it also has properties that can enhance the child's immune system, reduce the risk of SIDS, and protect against chronic diseases later in life.  An exception in nutrient supply from breast milk is that of vitamin D.  Vitamin D is not present in breast milk in sufficient quantities to support bone growth.  Deficiency in vitamin D can result in weakened or stunted bone growth and higher risk of getting rickets, a vitamin D deficiency disease.  The additional intake can potentially be covered by exposure to the sun, but may not be enough for children with pigmented skin, particularly due to other recommendations of lessened sunlight exposure.  It is often recommended that infants be fed supplements to make up for vitamin D, provide iron for muscle growth, and receive fluoride for teeth health.  Further, baby's are often given a single dose of vitamin K at birth, to promote earlier growth of intestinal bacteria, which can prevent bleeding (Sizer & Whitney, 2013).

Infants can typically begin eating solid foods at the age of approximately 5 months, but primarily depends on his or her individual needs.  When feeding solid foods to infants, it is compulsory for the parents to ensure the infant is physically ready to receive it, the food has sufficient nutrients, and that the infant does not have food allergies to what is being fed.  Primary nutrients needed during this time of life are iron and vitamin C, to support the infant's rapid growth.  This is usually insufficient in breast milk and formula, once the child reaches 4 to 6 months of age and therefore must be supplied through food, such as cereals, meat, or legumes (Sizer & Whitney, 2013).

At the age of 8 months, a baby is able to sit upright and sufficiently control limbs to support the eating process for solid foods.  Under supervised conditions, the baby can then be encouraged to eat small solid foods, such as crackers.  Adult supervision is required at this time, to guard against choking.  As time progresses, parents can choose from a wide variety of baby foods available at the store, or they can make their own by blending table food.  If this path is chosen, however, salt and sugar must be excluded from food.  At the age of 1 year, a baby can typically be transitioned to cow's milk and begin eating other foods that resemble those of their adult counterparts (Sizer & Whitney, 2013).

During early and middle childhood, a child's nutrient needs can vary widely, due to the variety of energy demands and the variability of growth.  However, it is important that parents remember that a child continues to grow until he or she reaches adolescence and, therefore, requires sufficient quantities of the nutrients needed to support that muscular and bone growth.  Overall, most nutrient demands begin to taper off as the child gets older, relative to his or her weight.  However, glucose demands are similar to those of an adult, since a child's brain and neurological structure has already development significantly.  As the child's age progresses, parents should begin instilling dietary habits that will carry on throughout the child's life.  For instances, introducing new foods and setting examples of limiting intakes of foods of low nutrient density (Sizer & Whitney, 2013).  This is also important as the child begins school and may being making choices of their own on what and how much to eat.  Public schools are beginning to offer healthier choices in cafeterias and vending machines, so nutrition education can encourage students to make wiser choices when eating away from their parents (Lytton, 2010).

Adolescence

Food choice becomes even more of a common thing when children become adolescents.  Indeed, parents only partially influence the dietary choices they make.  As they go through adolescence, both boys and girls experience spurts in growth and undergo a variety of hormonal changes.  Depending on whether they are in a growth spurt and their activity levels, the energy requirements can vary widely.  In addition, it is often difficult to measure weight levels in determining what is healthy and what is not, as traditional measurements are of little use.  To accommodate the growth spurts and significant body changes, doctors often use growth charts to measure an adolescent's progress.  During so many changes, teens can become depressed, as they may think they are too skinny or fat, even though these types of changes can be normal at any given time (Sizer & Whitney, 2013).  The depression can lead eating disorders, too, but it has been observed that increasing intakes of essential fatty acids from fish can help diminish the likelihood of their occurrence (Allen, et al., 2013).  It is important, however, to distinguish between the natural and healthy weight gains during growth spurts from the overall trend toward childhood overweight over the past several decades.  The number of overweight teens have more than tripled over the past four decades (Center for Disease Control, 2004).  An illustration of overweight trends in children is shown below.

Child and Adolescent Overweight Trends (Center for Disease Control, 2004)

Clearly, the nutrient needs of adolescents demand sufficient quantities to keep up with their energy, hormonal, and growth requirements.  For both boys and girls, the need for iron is essential, but not for the same reasons.  For growing boys, iron is needed to support the construction of lean tissue.  For girls, iron is needed to replace that which is lost in the blood during menstruation.  Girls are often found to be anemic, as they do not consume sufficient quantities of iron-rich foods.  As both girls and boys undergo growth spurts, bone development is critical.  Therefore, sufficient quantities of calcium and vitamin D, to facilitate its absorption, are needed.  Unfortunately, the vast majority of teens have insufficient intakes of calcium, which has an adverse effect on bone development and increases the risk of bone diseases and osteoporosis in later life (Sizer & Whitney, 2013).

Although adolescents choose the foods they consume, adults play a crucial role in helping them make wise dietary choices, providing nutritional knowledge and examples of healthy eating.  Moreover, adults have much control over the foods available within the household, including the refrigerator and cupboards.  Keeping healthy foods readily accessible for meals and snacks is an important step in providing teens with the nutrients they need during this critical time, as well as preparing them for eating healthy as they proceed into adulthood (Sizer & Whitney, 2013).

Adulthood

As adolescents cross over into adulthood, many nutrient requirements begin to decrease as the age increases.  The dietary habits they acquired during adolescence will play important roles in their health for the remainder of their lives.  As people age, the ratio of protein to overall caloric intake remains the same.  However, the overall energy needs tend to decrease, as metabolism and activity levels decrease, as well as lean muscle tissue.  Fiber intakes are also recommended to be high, which can help guard against constipation as muscles in the colon weaken (Sizer & Whitney, 2013).

As people age, they should pay special attention to dietary fat intakes, increasing intakes of the essential fatty acids to maintain neurological function, while decreasing intakes of saturated fats.  Research has shown that certain types of fats can affect arthritis and being overweight can also inflict pain on the joints (Sizer & Whitney, 2013).  Although the bones have stopped growing, calcium is still needed in the blood to support proper functioning of the heart.  If insufficient calcium blood levels exist, the body will begin to pull it from bones, lessening bone density.  Thus, older people should drinks two cups of milk per day or take calcium supplements.  Along these lines, vitamin D is also necessary to maximize absorption of calcium and maintain bone density (Hodgkin, 2004).  Unlike other vitamins, the absorption of vitamin A appears to increase as someone ages.  Thus, increasing vitamin A consumption is not recommended.  In fact, some researchers have suggested lowering the the daily recommended amounts for older people (Sizer & Whitney, 2013).

As people get older, the effectiveness of the digestive system diminishes, resulting in decreased absorption of nutrients, and constipation.  In addition, decreases in stomach acid may lead to overgrowth of bad bacteria in the gut, further decreasing absorption.  Absorption of nutrients can be improved by increased initial chewing and consumption of slow-cooked meals, where food bits are broken down further up-front.  Further, probiotic supplements can be used to counteract the growth of bad bacteria in the gut and optimize its bacterial content (Joshi & Lamb, 2014).

Conclusion

To maximize health, it is necessary to have optimal nutrients throughout an entire lifespan.  Such conditions are not only your responsibility, but those of your parents as well.  Nutrition becomes important before they are even conceived and does not cease until after death.  Throughout an entire lifetime, the body uses the same nutrients, but it demands them in different quantities to support its remarkable development.  Deficiencies in important nutrients, particularly during critical time periods of development, can result in permanent damage and have tragic consequences.

References

Allen, K. L., Mori, T. A., Beilin, L., Byrne, S. M., Hickling, S., & Oddy, W. H. (2013). Dietary intake in population-based adolescents: support for a relationship between eating disorder symptoms, low fatty acid intake and depressive symptoms. Journal Of Human Nutrition & Dietetics, 26(5), 459-469. doi:10.1111/jhn.12024

Center for Disease Control. (2004). Trends in Child and Adolescent Overweight. Retrieved from Center for Disease Control: http://www.cdc.gov/nchs/data/hestat/overweight/overweight_child_03.gif

Hodgkin, G. E. (2004, Mar). Lifetime nutrition. Vibrant Life, 20, 24-25,27-29. Retrieved from http://search.proquest.com/docview/216551890?accountid=32521

Joshi, M. R., & Lamb, N. (2014). The use of probiotics to help manage changes in the gut as people age. Primary Health Care, 24(8), 35-41.

Lytton, T. D. (2010). AN EDUCATIONAL APPROACH TO SCHOOL FOOD: USING NUTRITION STANDARDS TO PROMOTE HEALTHY DIETARY HABITS. Utah Law Review, 2010(4), 1189-1221.

Rumanaz Shahid, A., & Alam, A. (2012). Pregnancy and Nutrition. Bangladesh Journal Of Medical Science, 11(4), 267-272.

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

The Role of Diet in Preventing Underweight, Overweight, and Obesity

In my last post, I discussed the digestive system and how the body requires sufficient intakes of the essential nutrients and energy.  However, when the body does not take in the same amount of energy as it uses, health problems can result.  Quite simply, the body should use the same amount of energy as it takes in, in order to maintain the same weight.  Variations in this will lead to a person being underweight, overweight, or obese, which is severely overweight.  Each condition can pose health problems and diet plays a large role in its prevention.  Although weight is an important attribute of determining what is healthy, the more important component is the amount of fat, or adipose tissue, one has in proportion to that of lean tissue.  This ration is indicative of your body composition, which is an amalgamation of your dietary and activity behaviors over an extended period of time (Sizer & Whitney, 2013).

Underweight

In the United States, the condition of underweight is not very prevalent, affecting less than 2 percent of the population.  However, those people that are underweight have increased risk of death in the hospital or fighting wasting diseases.  For instance, an underweight person lacks the fat reserves necessary to go for an extended period of time while waiting for tests in the hospital.  Moreover, this hinders their ability to fight diseases that consume large amounts of energy, such as cancer.  Thus, underweight people are encouraged to gain weight to a healthy level and build up fat reserves (Sizer & Whitney, 2013).

Consuming sufficient quantities of nutrients and energy, in a balanced way, can help people avoid becoming underweight.  In addition, this diet can aid underweight people in gaining the necessary weight and fat reserves.  Recommended techniques in helping underweight people gain weight are to eat more frequently, choose nutrient-dense foods and drinks, timing when drinks are consumed, snacking more often, adding extra components to meals, and engaging in strength-building exercises (Zeratsky, 2014).

Overweight and Obesity

Health professionals use a measurement known as the Body Mass Index, or BMI, to generally assess whether someone is of a healthy body weight.  The BMI represents a ratio between a person's height and weight.  As the BMI exceeds a value of 25, health risks begin to rise.  An overweight person is defined by having a BMI of 25 to 29.9.  Obesity is a form of extreme overweight, with a BMI of 30 or higher.  Significant health risks are associated with obesity.  In addition to the BMI, the waist circumference is also considered when evaluating the health of an individual.  In particular, large amounts of visceral fat, that which is located in the abdominal cavity, is associated with high health risks (Sizer & Whitney, 2013).  Thus, it is of utmost importance that overweight and obese people try to adjust their behaviors to reverse the situation as much as possible.  Much of this is done through exercise, but just as important is a person's diet.  Diet played a large role in making someone overweight or obese and it, therefore, must play a role in reversing it.  In America, the obesity rate has been on the rise for the past several decades.  Many consider the increased portion sizes and growth of processed foods to be major contributors (Sizer & Whitney, 2013).  Poor menu offerings in public schools have also been attributed to obesity, in that the children learn bad dietary habits from the very institutions that should be educating them (Lytton, 2010).  Illustrations depicting these correlations, and the increased consumption of food away from home, are presented below.

U.S. Obesity Chart (DietDatabase.com, 2014)

Fast Food Obesity Chart (FoodWallPaper, 2012)

Although similar, the diet considerations for reversing overweight and obesity conditions are not identical to preventing them in the first place.  The primary difference is in energy consumption and the setting of goals.  For people that are already overweight or obese, the goals for weight loss must be realistic and achievable.  For instance, the first goal may simply be to stop gaining weight.  Next, a realistic goal would be to lose 5 to 10 percent of body weight within the next year.  For overweight people, a reduction of 10 percent body weight has been shown to have significant health benefits.  An important dietary consideration for weight loss is to decide on the proper amount of energy intake.  As noted earlier, taking in less energy than is needed by the body is the only way to lose weight.  However, it is not recommended for a person to take extreme measures and cut out enormous amounts of calories immediately.  Instead, obese people should reduce caloric intake by 500 to 1,000 calories per day and overweight people should reduce caloric intake by 300 to 500 calories per day.  Such cuts allow for weight loss of 1 to 2 pounds per week and can do so in a healthy manner.  Cutting calories more drastically could result in loss of lean tissue and be detrimental to health.  Eating smaller, more frequent meals can also help by moderating the feeling of hunger (Sizer & Whitney, 2013).

The remainder of the diet considerations for losing weight or the prevention of becoming overweight are largely the same.  One of the most crucial tasks is to ensure the body is getting sufficient quantities of the nutrients it needs.  This is done by ensuring intakes are adequate, balanced, and consist of nutrient-dense foods.  Additional dietary steps include cutting back on saturated fats and identifying and eliminating foods that contain excessive and empty calories (Sizer & Whitney, 2013).

Conclusion

The dietary choices we make each day eventually add up and govern our body composition, made up of fat and lean tissue.  Choosing an appropriate diet can help prevent a person from becoming underweight or overweight to begin with, but it can also help people who are already in those conditions achieve better health.

References

DietDatabase.com. (2014). US Obesity Chart. Retrieved from DietDatabase.com: http://dietdatabase.com/wp-content/uploads/2013/12/us-obesity-chart.png

FoodWallPaper. (2012). Fast Food Obesity Chart. Retrieved from Food Wall Paper: http://foodwallpaper.info/fast-food-obesity-chart-2012/

Science In Everyday Terms. (2012). The Digestive System: How it Works! Retrieved from Science In Everyday Terms: http://scienceineverydayterms.blogspot.com/2012/12/the-digestive-system-how-it-works.html

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

Zeratsky, K. (2014). Underweight? See how to add pounds healthfully. Retrieved from Mayo Clinic: http://www.mayoclinic.org/healthy-living/nutrition-and-healthy-eating/expert-answers/underweight/faq-20058429

Essential Nutrients and the Digestive System

In my previous post, I discussed the dietary choices of humans and what described a healthy diet.  However, what exactly makes a healthy diet healthy?  The answer lies in what it contains and how the body is able to extract and use the components in an optimal fashion.  The human body is remarkable in its form and function.  Fundamental to its operation is the need for energy.  Ultimately, this energy originates from the sun and is captured by plants.  Through the process of photosynthesis, plants convert and stores the sun's energy in their tissues, which is later consumed by humans either directly by eating the plants or by way of eating animals that eat plants.  Plants and animals possess many of the fundamental elements, known as nutrients, the body requires to function.  Thus, humans must consume sufficient quantities of nutrients to survive.  The human digestive system is a complex set of components that work together to extract the energy and nutrients contained in plants and animals and use them to sustain life (Sizer & Whitney, 2013).

The Essential Nutrients

As mentioned before, the fundamental components required by the body come in the form of nutrients, which are present in all foods that we consume.  Nutrients are families of molecules that perform a wide variety of functions within the body and are vital to the life of a human being.  Indeed, humans are actually comprised of the same materials as the foods they eat, in substantially different quantities, of course.  There are six kinds of nutrients the body requires, four of which are organic in nature, because they contain carbon and are derived from living things.  The organic nutrients include carbohydrates, fats, protein, and vitamins.  The two non-organic nutrients are water and minerals.  Although the body can make certain nutrients by itself, many are known as essential nutrients, in that the body cannot make them.  Instead, they must be taken in through the process of eating.  Each of the six families of nutrients has at least one essential nutrient.  In some cases, such as water, minerals, and vitamins, the entire family is comprised of essential nutrients (Sizer & Whitney, 2013).

Of the six nutrients, water is the most abundant, comprising almost 60 percent of a person's weight.  Water is crucial to the body's operation as it is the primary transport mechanism for all nutrients and a wastes throughout the body.  As it is lost constantly in the body, it must be replenished in a timely manner or death will occur. (Sizer & Whitney, 2013).

The vitamins and minerals are families of nutrients that provide no energy to the body.  Rather, they serve as regulators that are vital to all processes within the body, including digestion, muscle movement, converting nutrients to energy, and growing tissue.  Some minerals are used in the physical structures within the body.  For instance, calcium and phosphorous are primary components of bone in the skeletal system (Sizer & Whitney, 2013). 

The remaining three of the four organic nutrients are known as energy-yielding, in that they can be converted to energy that the body can use.  The energy-yielding nutrients are carbohydrates, proteins, and fats, also known as lipids.  Because they provided the bulk of energy to the body and must be consumed in relatively large quantities, the three energy-yielding nutrients are also called macronutrients.  While carbohydrates and fats primarily provide energy, proteins serve a dual-purpose, in that they provide energy and provide building structures to form the muscles and other tissues within the body.  It is important to note that alcohol can also provide energy, but because it is non-essential to life and can be harmful, it is not considered a nutrient (Sizer & Whitney, 2013).

The amount of energy contained in food is measured in kilocalories, commonly referred to as simply calories.  A gram of each of the three energy-yielding provides a fixed amount of calories, with carbohydrates and proteins each providing 4 calories per gram and fats providing 9 calories per gram.  Because each nutrient serves a purpose within the body, one must follow a diet that provides sufficient quantities of each nutrient and the average amount of energy required by the body.  Too little of some essential nutrients will lead to malnutrition, while too much of some nutrients can be toxic.  Moreover, to little energy can lead to being underweight, while too much energy can lead to being overweight, both of which can be problematic (Sizer & Whitney, 2013).

As mentioned in the previous blog post, the USDA's Dietary Guidelines provide guidance on what foods to eat from the five different food groups, as well as the recommended quantities from each.  Following a well-planned diet that adheres to these recommendations will supply most people with sufficient quantities of all essential nutrients, while keeping calorie intakes under control.  For instance, the fruits and vegetables food groups provide dietary fiber, potassium, magnesium, vitamin A, vitamin C, folate, and other important nutrients.  Foods from the grains food group provide iron, thiamin, folate, niacin, selenium, and substantial fiber to the diet, which helps in digestion and slows sugar absorption.  It is recommended that at least half of all grains consumed should be made up of whole grains, due to the additional fiber and health benefits of the whole-grain wheat kernels.  The protein food group provides protein, essential fatty acids, the B vitamins, iron, and other important vitamins and minerals.  Finally, the dairy food group provides a source of protein, calcium, potassium, and vitamins A and D via fortification.  All five food groups provide energy via one or more of the energy-yielding nutrients of carbohydrates, fats, and proteins (Sizer & Whitney, 2013).

The Digestive System

The consumption of nutrients via food does no good unless the body can extract the nutrients from the food and transform them to a form it can use.  The human digestive system does just that with incredible efficiency.  The digestive system is comprised of both mechanical and chemical components and it's primary function is to break down the food to its fundamental components, known as digestion, and then absorb the nutrients and other products.  Remainder material, such as fiber, is then excreted (Sizer & Whitney, 2013).

The digestive tract is flexible and muscular tube, around 26 feet long, that includes the mouth, throat, esophagus, stomach, small intestine, large intestine, the rectum, and the anus.  Interestingly, the digestive tract is entirely outside of the human body and is merely a cavity running from the mouth all the way to the anus.  Food passing through the digestive tract only enters the body when it is absorbed through the digestive tract walls (Sizer & Whitney, 2013).  An illustration of the major components of the digestive tract is shown below.

The Digestive System (Science In Everyday Terms, 2012)

The digestive system works in a progressive manner to break down food and absorb what the body needs from it, while excreting the unneeded components.  As mentioned earlier, digestion works at both a chemical level, using enzymes and acid, as well as a physical level.  As food enters the mouth, the physical act of chewing breaks the food into smaller pieces, increasing its surface area.  The salivary glands in the mouth produce saliva, which help to lubricate and break down the food using a variety of enzymes.  For instance, salivary enzymes already begin to break down break into glucose, before you even swallow it.  The chewed, partially broken down, mass of food is known as a bolus and is now ready to be swallowed (Mayo Clinic, 2014).

Upon swallowing a bolus, the food is sent to the esophagus, which contains a number of ringlike muscles.  Through a synchronized muscle process called peristalsis, the bolus is transferred from the throat to the stomach.  After entering the stomach, the food is broken down even further.  From a physical perspective, the stomach is very muscular and performs contractions to squeeze, churn, and mix its contents to liquefy the food.  In addition, the stomach uses chemical actions to assist in the process, releasing stomach acid and enzymes.  The end result of the processing in the stomach is that the food is turned into a liquid substance known as chyme (Mayo Clinic, 2014).  By the time the chyme is ready to leave the stomach, it looks nothing like the original food that entered the mouth.  Instead, it is in prime condition to be absorbed unraveled and prepped, the starches have been partly split, and the fats have been separated from the rest of the mass (Sizer & Whitney, 2013).

The chyme then proceeds through the pyloric valve, at the bottom of the stomach, and enters the small intestine through a series of squirts, so that small amounts enter at a time.  In fact, only about an eighth of an ounce enters the small intestine at a time.  The rest of the chyme continues to be mixed in the stomach until it, too, gets squirted into the small intestine.  Upon entering the small intestine, the chyme gets mixed with a number of digestive juices that are produced from the pancreas, liver, and gallbladder.  The pancreas produces digestive enzymes that work to break down carbohydrates, fats, and proteins.  The pancreatic juice also contains a bicarbonate to neutralize the acid that has entered the small intestine from the stomach.  Because fats need a little help in digestion, the liver produces bile, an emulsifier that helps to digest them.  Finally, the gallbladder stores the bile, so that it can be excreted in precise amounts (Mayo Clinic, 2014).

The digestive enzymes in the intestine and pancreatic juice work together to act on the chemical bonds that hold the larger nutrients together.  As this happens, the molecules continue to get broken down into smaller and smaller pieces, suspended in the intestinal fluids.  Additional enzymes are present on the intestinal walls themselves, to help break the components down even further, just before absorption.  Once this final breakdown occurs, the pieces that once were food are now small enough to be absorbed and pass through the intestinal walls.  Through this process, virtually all macronutrients are absorbed before leaving the small intestine (Sizer & Whitney, 2013).  The remaining material is a combination of water, electrolytes, and waste, such as undigestible plant fiber and dead cells from the digestive tract.  As this passes through the colon, nearly all of the water is reabsorbed, leaving a soft substance called the stool.  The muscles of the colon separate this into small segments and push it into the lower colon and rectum for later excretion through the anus (Mayo Clinic, 2013).

Although much cannot, some kinds of fiber can also be broken down further by the large quantity of bacteria living in the colon (Sizer & Whitney, 2013).  Indeed, up to 1,000 bacterial species live in the bowel and the mass of bacterial cells in the colon weighs over 3 pounds.  This bacteria, and its microflora, are essential in aiding digestion and increasing the body's immune function (Joshi & Lamb, 2014).

Conclusion

The body's ability to break down food into its most basic components and absorb them for its own use is remarkable.  Without this incredibly efficient and complex system, the essential nutrients from each of the six nutrient families could not be obtained and human life would not be possible.

References

Joshi, M. R., & Lamb, N. (2014). The use of probiotics to help manage changes in the gut as people age. Primary Health Care, 24(8), 35-41.

Mayo Clinic. (2014). Slide show: See how your digestive system works. Retrieved from Mayo Clinic: http://www.mayoclinic.org/digestive-system/sls-20076373?s=1

Science In Everyday Terms. (2012). The Digestive System: How it Works! Retrieved from Science In Everyday Terms: http://scienceineverydayterms.blogspot.com/2012/12/the-digestive-system-how-it-works.html

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

Healthy Diet Characteristics and Factors Affecting Dietary Choices

In my previous post, I discussed the connection between nutrition and chronic diseases, noting the importance of wise dietary choices in increasing the likelihood for a long and healthful life.  Only two lifestyle choices, that of tobacco and alcohol usage, have a greater influence on health than that of diet.  What, then, differentiates wise dietary choices from unwise ones?  Consider that an average person consumes more than 70,000 meals in his or her lifetime.  During this period, he or she will have disposed of over 100,000 pounds of food and will have replaced nearly all cells in the body many times over.  Each of the dietary choices made along the way contributes to the current state of your health (Sizer & Whitney, 2013).  Thus, the old saying "you are what you eat" is very true.  It is important, then, that your diet provide the materials needed to support the development and maintenance of muscles, bones, skin, blood, and other components making up your body.  Deficiencies in any of the components required by your body will eventually have an adverse affect on your body, including increased risk of disease or impaired function (Sizer & Whitney, 2013).

The Characteristics of a Healthy Diet

A healthy diet is something that cannot be adopted overnight.  Instead, it is learned and then repeated until it becomes a habit.  It is a lifestyle involving the consumption of food that exhibits five primary characteristics, including that of adequacy, balance, calorie control, moderation, and variety.  Adequacy in the diet refers to the supply of nutrients required by the body and whether they are sufficient in quantity.  For instance, the body requires vitamin A for immune functions and eyesight.  Iron is an essential nutrient for muscular activity and neurological health.  Not getting enough of any of the essential nutrients will have an adverse effect on health (Sizer & Whitney, 2013).

The concept of balance in the diet refers to the fact that no single food contains sufficient quantities of all 40 or so required nutrients.  Therefore, one must balance the consumption foods, so that the aggregate supplies the nutrients needed by the body to function properly.  For example, iron and calcium are rarely sufficiently present in a single food, but the body requires both.  Thus, it is necessary to eat a food that is rich in calcium and eat another food that is rich in iron.  All the while, it is important that excess consumption of any one nutrient is avoided.  This leads to the next subject, which is calorie control.  Calories are a measurement of the energy a food contains.  In a healthy diet, the body must not consume less energy than it needs in a given time period, nor should it consume more energy than it needs.  Consuming less or more energy than is required will result in weight loss or gain, respectively, both of which can have adverse effects on health (Sizer & Whitney, 2013).

It is also important to practice moderation in the consumption of certain food components.  Items such as fat, salt, and sugar, can have many negative impacts to health if consumed in excess.  Thus, their intakes should be moderated.  In addition to negative food constituents, even essential nutrients should be limited, as they can be often be harmful if taken in excess.  Finally, variety in the diet ensures that people do not consume the same foods every day.  This is important, in part, because of the possibility of contaminants and toxins that may be present in a given food.  Further, consumption of a variety of foods increases the likelihood that sufficient nutrients will be obtained by the aggregate of foods (Sizer & Whitney, 2013).

The Dietary Reference Intakes (DRI) are established by a panel of nutrition experts and are published in the United States and Canada.  The DRI provides dietary guidelines on the consumption of carbohydrates, fiber, lipids, protein, water, energy, vitamins, and minerals, to ensure adequate nutrition is received for the majority of people.  Since no two people are exactly the same, nor are the nutritional needs of differing groups of people, the DRI provides specialized dietary recommendations for specific groups of people, including men, women, pregnant women, children.  Moreover, recommendations vary depending on the age range of each group.  Consequently, individuals can easily determine the relevant recommendations in a manner that is highly detailed for their particular circumstances.  On average, most people should strive to obtain 100 percent of the DRI intake recommendations for each of the nutrients, to ensure a healthy diet (Sizer & Whitney, 2013).

Complementing the DRI, the United States Department of Agriculture updates and publishes the Dietary Guidelines every five years.  These are used to provide guidance to Americans in establishing a healthy eating plan.  In recognizing the trends of obesity, diabetes, and other diet-related chronic diseases, the latest Dietary Guidelines established several key recommendations, covering four major areas.  These were to 1) balance calories, 2) eat more nutrient-dense foods, 3) eat less of certain foods, and 4) build a healthy eating pattern (Sizer, & Whitney, 2013).

In general, the Dietary Guidelines recommends that people should eat more fruits, vegetables, fish and seafood, whole grains, and low-fat milk products.  In contrast, Americans should reduce intakes of refined grains, solid fats, added sugars, and salt.  To help people understand and manage the recommendations more easily, the Dietary Guidelines makes use of a food group plan, which categorizes foods into five distinct groups.  The five food groups consist of Fruits, Vegetables, Grains, Protein Foods, and Dairy.  The food groups ensure that a diet will be balanced and span a variety of foods within a given group.  An illustration of the food groups and their related portions is provided below.

The Five Food Groups of the Dietary Guidelines (USDA, 2014)

The proportions of each group and quantity within a given group are provided in further detail in the Dietary Guidelines.  A wide variety of tasty meals can be made, while still being nutritiously healthy.  In fact, there is an entire Pinterest page dedicated solely to recipes that comply with the Dietary Guidelines and its government supported campaign, known as MyPlate.

The Challenges of Choosing a Healthy Diet

Despite the wealth of tasty and healthy recipes available, many find it difficult to know what foods to eat and to which extent.  For starters, there is much ambiguity in the marketplace as to what is healthy and what is not.  Food manufacturers have a fair amount of flexibility in what is place on food labels and the claims used by many skirt around regulations to cause consumer confusion.  Compared to the limited food choices a century ago, today's food choices can be mind-boggling.  The foods of a century ago were largely unprocessed and often can directly from the farm.  In contrast, today's food offerings are often refined, processed, packaged, and often have many additives to ensure shelf longevity and appealing taste.  Portion sizes have also increased substantially over the past several decades, particularly in fast food and full-service restaurants.  It is challenging to find products that do not contain added sugars or have refined grains.  Unfortunately, many Americans have become accustomed to eating convenient foods, loaded with calories and unhealthy additives, and in substantial portion sizes (Sizer & Whitney, 2013).

Adding to the the difficulties of healthful dietary choices is the fact that even in the schools, the menu choices have traditionally not been health oriented.  Items offered in school cafeterias that have high concentrations of fat or sugar, such as pizza, fries, desserts, burgers, and soda have encouraged children from eating healthy.  Such offerings from schools have not contributed to increasing awareness of the dangers in consuming such foods.  Fortunately, recent efforts are being made to raise awareness and offer more health-conscious foods in public schools (Lytton, 2010).  It has also been observed that kids respond heavily to food advertisements and can exert influence on whether these food products are purchased.  Moreover, traditional pro-nutrition campaigns have done little to deter children from wanting unhealthy foods, as improving nutritional knowledge alone is ineffective.  Instead, research has shown that nutritional messages tailored to children have much more efficacy in this regard.  For instance, it was found that a cartoon illustrating the harmful effects of sugary snacks and foods was able to influence children more more effectively than previous formal campaigns (Hota, Cáceres, & Cousin, 2010).  It has also been suggested that even the governing body making dietary guideline recommendations operates with many conflicts of interest, thereby purposely adding ambiguity in the recommendations (Gustafson, 2014).

Factors Affecting Dietary Choices

There are many factors that drive the food choices people make, including social and cultural, psychological, philosophical, and physical factors.  From a social and cultural perspective, a person's heritage plays a large role in the types of food consumed.  People of Mediterranean descent, for instance, often tend to eat a diet rich in fish and oils, but low in red meat.  The social circumstances of today expose people from different ethnic backgrounds to try new types of foods.  For instance, a person may try Indian cuisine for the first time when dining with coworkers.  In terms of psychological influences, the advertisement of food products heavily influences the food choices of Americans.  Other psychological aspects that influence food choice are whether someone finds emotional comfort in a given food or being in the habit of eating a particular food (Sizer & Whitney, 2013).

Many people have philosophical beliefs that lead them to choose certain foods over others, or avoid certain foods altogether.  For instance, certain religions consider discourage the consumption of pork or meet altogether.  Other religions discourage the consumption of food that isn't prepared in a certain way.  There are also people that believe consumption of animal meat is disrespectful of animals and, as a consequence, choose to eat a plant-based diet.  Finally, there are physical aspects that govern the food choices of a great many people.  In America, many citizens are fortunate to have access to a large variety of foods.  However, this is not necessarily so in many poverty-stricken parts of the world.  In many cases, people simply do not have access to certain foods, either because it is not present in the environment or because they cannot afford it.  Consequently, many people in the world must eat what they have access, which often leads to severe malnutrition and its related health risks (Sizer & Whitney, 2013).

Conclusion

Eating a diet with sufficient quantities of nutrient-dense foods, from each of the five food groups, will ensure the body has the nutrients necessary to function properly.  Although making wise food choices can be difficult, Americans have many tools at their disposal to make informed decisions, including the DRI and Dietary Guidelines.  While the Internet provides a wealth of healthy recommendations and recipes, it is vital to obtain the information from only well-respected sources, to guard against ambiguity and misleading information.  The resources available allow most Americans to choose healthy diets that still conform to philosophical and cultural beliefs.

References

Gustafson, C. (2014). Michael Greger, MD: Reversing Chronic Disease Through Diet; Addressing the 2015 USDA Dietary Guidelines Committee. Integrative Medicine: A Clinician's Journal, 13(2), 22-24.

Hota, M., Cáceres, R. C., & Cousin, A. (2010). Can Public-Service Advertising Change Children's Nutrition Habits?. Journal Of Advertising Research, 50(4), 460-477.

Lytton, T. D. (2010). AN EDUCATIONAL APPROACH TO SCHOOL FOOD: USING NUTRITION STANDARDS TO PROMOTE HEALTHY DIETARY HABITS. Utah Law Review, 2010(4), 1189-1221.

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

USDA. (2014). Build a Healthy Meal. Retrieved from Choose My Plate: http://www.choosemyplate.gov/food-groups/downloads/TenTips/DGTipsheet7BuildAHealthyMeal.pdf

USDA. (2014). Choose My Plate My Plate Graphic. Retrieved from Choose My Plate: http://www.choosemyplate.gov/images/MyPlateImages/JPG/myplate_green.jpg

The Connection Between Nutrition and Disease

In the United States, chronic diseases easily outweigh infectious diseases as the primary cause of death.  Indeed, heart disease, cancer, stroke, and diabetes are collectively responsible for 56 percent of deaths in the United States.  It might surprise some people to learn that these diseases are each influenced by diet, some to a large degree.  While it is true that a person's genetics, activity level, lifestyle choices, and environment play a large role in whether he or she will contract a chronic disease, making wise decisions in dietary choices can lessen the likelihood or severity of such chronic diseases (Sizer & Whitney, 2013).

Diabetes

Diabetes, also known as hyperglycemia, is a metabolic disease that is distinguished by elevated levels of blood glucose, caused by a lack of sufficient quantities of insulin, or insulin that is ineffective (American Diabetes Association, 2014).  Diabetes alters the metabolism of cells within the body, which can lead to a host of problems, including blindness, limb loss, kidney failure, circulation loss, and nerve function loss.  As such, it is a leading cause of death in the United States.  Diabetes afflicts nearly 26 million people in the United States, with 7 million not even being aware they have it.  Moreover, nearly 79 million people have prediabetes, a condition dangerously close to becoming fully diabetic.  Identified through a variety of blood tests, those that have prediabetes have a chance to reverse it, if they catch it early enough and alter their diet and behaviors accordingly (Sizer & Whitney, 2013).

Insulin is a hormone used by the body to trigger absorption of glucose in the blood, enabling the body to regulate the quantity of sugar in the blood at any given time.  It is the counterpart to the hormone known as glucagon.  Although Type-1 diabetes is primarily genetic in nature and relates to the body's ability to produce sufficient quantities of insulin, the vast majority of diabetics in the United States have Type-2 diabetes.  In Type-2 diabetes, tissues in the body lose their sensitivity to to insulin and, therefore, do not consume the glucose in the blood as rapidly as desired.  The pancreas will initially attempt to respond by producing more insulin.  However, it is an exercise in futility, and will eventually result in the pancreas significantly reducing insulin levels and leaving blood glucose levels out of control (Sizer & Whitney, 2013).  An illustration of how insulin is used within the body to regulate blood glucose levels is shown below.

Roles of Glucagon and Insulin in Blood Glucose Regulation (Freudenrich, 2014)

The level of body fat contained within tissue is directly related to its ability to respond to insulin and, thus, affects the glucose levels within the blood.  Obesity, a condition of excessive body fat, is directly associated with a large percentage of people that are afflicted with Type-2 diabetes.  Type-2 diabetes can be largely prevented by maintaining a healthy body weight, eating diets low in saturated fat and high in nutritious foods, limiting alcohol intake, and obtaining regular physical activity (Sizer & Whitney, 2013).

Cardiovascular Disease

More than 82 million people suffer from cardiovascular disease in the United States.  Cardiovascular disease (CVD), collectively referring to diseases of the heart and circulatory system, is a leading cause of death for Americans, claiming almost 1 million lives annually.  Nutrition plays a significant role in the development of CVD.  For instance, atherosclerosis, or hardening of the arteries, is a core component of most forms of CVD and is highly correlated to the amount of saturated fat taken in through diet.  Plaque formation is a complicated process, but originates from particles of low-density lipoprotein (LDL) cholesterol in the bloodstream being trapped in blood vessel walls.  Free radicals in the blood cause LDL cholesterol to oxidize and eventually harden into plaque via the formation of foam cells.  The process is exacerbated by muscle cells, in an attempt to heal the damage, but they actually contribute to the hardening process by melding with the foam cells themselves.  As plaque builds up, the risk of rupture increases, which can lead to blood clots.  Blood clots can lead to severe injury or death, caused by stroke or a heart attack (Sizer & Whitney, 2013).  The relationship between LDL cholesterol, foam cells, and the arterial wall is illustrated below.

Cholesterol and Coronary Artery Disease (American Heart Association, 2014)

In addition to atherosclerosis potentially leading to stroke or heart attack, it also heightens the risk of hypertension, also known as high-blood pressure.  In fact, hypertension and atherosclerosis each cause the other to worsen over time.  The stress of hypertension on the arteries causes more injury to them, leading to more blood clots and plaque buildup.  The additional plaque buildup, in turn, leads to addition hypertension in the vicious cycle.  The good news is that Americans can substantially lessen their risk of CVD, and even reverse some of its advancement, by making wise choices in diet, lifestyle, and activities.  Increased physical activity results in the more efficient pumping of blood and the ability of muscle tissues to absorb oxygen, ultimately reducing the amount of heartbeats required to accomplish the same amount of work.  Moreover, exercise increases the amount of HDL cholesterol in the blood, which works to combat the effects of LDL cholesterol and plaque buildup.  The resultant lean muscle tissue has many other benefits, such as improved insulin sensitivity, lessening the risk of diabetes.  Even increasing activity to 30 minutes, 5 times per week, will substantially lessen a person's risk for CVD, along with many other chronic diseases (Sizer & Whitney, 2013).

In addition to physical activity levels, a person's diet plays an important role in the development of CVD.  Following an atherogenic diet, or that which is high in saturated and other fats, has substantial adverse effects on cardiovascular health.  Cutting back on foods high in cholesterol, saturated and trans fats, combats obesity and insulin resistance, as well as promotes neurological function (Sizer & Whitney, 2013).  Regular consumption of fish, with its omega-3 polyunsaturated fatty acids, has recently been shown to lower risk of death from CVD by as much as 25 percent (Weichselbaum, Coe, Buttriss, & Stanner, 2013).

Cancer

In the ranking of leading causes of death, cancer takes second place to cardiovascular disease by a very small margin.  While it generally is not as affected by diet as is CVD, most cancers are influenced by dietary and lifestyle choices, as well as environmental surroundings.  Cancer, which develops from cellular exposure to carcinogens, is more likely to develop as the exposure to carcinogens increases.  From a lifestyle standpoint, smoking has long-been proven to increase the risk of lung and other cancers, but it is less well-known to the public as to the role alcohol consumption plays in cancer development.  Indeed, research has shown that there is a strong correlation between alcohol and tobacco use with head and neck cancers, and alcohol by itself increases the risk of mouth, throat, esophageal, and breast cancers.  Moreover, the adverse impact that alcohol has on the liver promotes liver cancer (Sizer & Whitney, 2013).

The common theme of physical activity, fat intake, and obesity, plays a critical role in cancer, as it does in other chronic diseases.  Obesity is highly associated with colon, breast, endometrial, pancreatic, kidney, and esophageal cancers, and is also suspected to be linked with gall bladder cancer.  The intake of fat and fatty acids speed the development of cancer in laboratory rats, when carcinogens are present.  This has not been proven in humans thus far, however.  Direct evidence of the contribution of fats toward cancer in humans notwithstanding, fat is a direct contributor to obesity, which alone should be enough to discourage its intake in abundance.  Further, red meat has been consistently shown to increase the risk of colon cancer (Sizer & Whitney, 2013).

Curiously, the intake of caloric energy has been shown to have direct correlation to cancer incidence.  Reduction in calorie consumption lowers risk of cancer.  This is further re-enforced by increased physical activity, which also lowers risks for obesity.  Finally, eating sufficient amounts of foods that are rich in fiber, folate, calcium, and vitamins E, C, and D, help to guard against cancer development.  It has been suggested that iron consumption, however, has been linked to colon cancer, but the exact cause is under study (Sizer & Whitney, 2013).

Malnutrition

 

Finally, the body's immune system is crucial in defending itself against chronic diseases.  In order to function properly, the immune system depends on sufficient intakes of vitamins and minerals.  For instance, vitamin C is necessary for white blood cells to kill intruders, while vitamin A supports immune cell and antibody response.  Folic acid is needed for proper cellular replication and zinc plays a role in antibody production.  All of these, and many more, are needed to support a healthy immune system.  Malnutrition, a sustained deficiency in one or more essential nutrients, allows disease to more easily develop.  Disease can then contribute to further malnutrition, leading to an unfortunate spiral of each building upon the other (Sizer & Whitney, 2013).  A recent study in Australia observed that the majority of patients exhibiting end-stage kidney disease were deficient in several vitamins, zinc, and folate.  Malnutrition was determined to be a contributor to decreased renal function and increased symptoms associated with end-stage kidney disease (Chan, Kelly, Batterham, & Tapsell, 2014).

Conclusion

Although there is no silver bullet to ensure someone does not become afflicted with disease, there is no question that the choices people make in diet and behavior directly influences the risks of disease.  It has been suggested by some nutrition experts that many chronic diseases can be reversed through diet, particularly that which is plant-based, including hypertension and diabetes (Gustafson, 2014). Clearly, obesity poses a serious threat in the development of the chronic diseases that are the leading causes of death in the United States.  Eating a varied diet of whole foods, limiting caloric intake, and engaging in regular physical activity are the best ways to lessen your risk of obesity and chronic diseases.

References

American Diabetes Association. (2014). Type 2 Diabetes. Retrieved from American Diabetes Association: http://www.diabetes.org/diabetes-basics/type-2/?loc=db-slabnav

American Heart Association. (2014). Watch, Learn and Live - Interactive Cardiovascular Library. Retrieved from American Heart Association: http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=chlcad

Chan, M., Kelly, J., Batterham, M., & Tapsell, L. (2014). A High Prevalence of Abnormal Nutrition Parameters Found in Predialysis End-Stage Kidney Disease: Is It a Result of Uremia or Poor Eating Habits?. Developmental Psychology, 50(9), 292-302. doi:10.1053/j.jrn.2014.03.008

Freudenrich, C. (2014). How Diabetes Works. Retrieved from howstuffworks: http://health.howstuffworks.com/diseases-conditions/diabetes/diabetes1.htm

Gustafson, C. (2014). Michael Greger, MD: Reversing Chronic Disease Through Diet; Addressing the 2015 USDA Dietary Guidelines Committee. Integrative Medicine: A Clinician's Journal, 13(2), 22-24.

Sizer, F., & Whitney, E. (2013). Nutrition: Concepts and Controversies (13th ed.). Mason, OH: Cengage Learning.

Weichselbaum, E., Coe, S., Buttriss, J., & Stanner, S. (2013). Fish in the diet: A review. Nutrition Bulletin, 38(2), 128-177. doi:10.1111/nbu.12021