Is Obesity Primarily An Environmental Disease Essay

, Research Paper

Obesity rates are soaring throughout North America (Wickelgren, 1998). With obesity reaching almost epidemic proportions in the United States, and the threat of a global epidemic, we must watch this alarming increase carefully (Hill & Peters. 1998). Obesity is defined as: “?an excess of adipose tissue?” (A Report of the Surgeon General, 1996). The two most common measures of obesity are Body Mass Index (BMI is a ratio of weight to height) and relative weight index, such as percent desirable weight (Metropolitan Life Insurance Company, 1959). BMI is the most frequently used measure of obesity as it has a strong correlation with more direct measures of adiposity, such as underwater weighing (A Report of the Surgeon General, 1996). Some have proposed that genetics are at the root of obesity. While genetics may play a role in obesity, it is still not clear what role this is (Chagnon et al., 2000). While a defacto underlying cause for obesity still remains clouded in mystery, the environment plays a large part in causing obesity (Hill & Peters, 1998). Hill & Peters (1998) see obesity as an environmental disease caused by the promotion of behaviours that lead to obesity. With the United States’ Institute of Medicine claiming that fat people cost the United States more than $70 billion annually in both direct health care costs and indirect ones such as lost productivity, this truly is an epidemic that must be solved. Americans spend another $40 billion per year on weight-loss treatments, mostly in the form of diets and dietary foods (Wickelgren, 1998). That is a total of approximately $110 billion dollars of the gross domestic product of the U.S., not a small sum of money in anyone’s books. Such a sum could surely be used more wisely elsewhere.

An individual with a BMI * 25 kg/m2 is considered overweight, while an individual with a BMI * 30 kg/m2 is considered obese (Hill & Peters, 1998). With over 22.5% of the current U.S. population considered to be clinically obese, compared to only 14.5% in 1980, there does not seem to be a cessation of this epidemic in sight (Hill & Peters, 1998). Goran and Weisners’ (2000) proposal that “… the inherently lower resting metabolic rate in women versus men is responsible for the higher adiposity rates in women…” is wanting, especially since the potentially modifiable factors of; less physical strength, less daily free-living physical activity, and lower total energy expenditure are more likely the cause of the differences in observed adiposity between men and women. Since our genetic makeup has not appreciably changed in the last twenty years, we cannot strictly attribute the explosion of obesity to genetics. As these biological causes of obesity are disproved, a focus on the environment as a reason for obesity is taking centre-stage.

With a multitude of environmental factors playing an ever-increasing role in the reasons for obesity, it is hard to focus on one reason as the ‘root’ cause of obesity. Ever-decreasing levels of physical activity, married with poor dietary habits are two likely causes of the obesity epidemic. Samaras et al. (1999) concluded that physical activity is the strongest environmental influence on total-body fat-mass in healthy middle-aged women. An inverse relationship was clearly apparent between physical activity and total-body and central abdominal fat (Samaras, 1999). Blackburn and Prineas (1983) also note that high rates of inactivity combined with easy access to energy-dense foods are responsible for the obesity phenomenon. The explosion in the availability of fast food in the last 10 years combined with an ever-decreasing need in our daily life to physically exert ourselves to complete our daily tasks has left us with obesity rates spiralling out of control. The increase in food availability and portion size at fast food restaurants (”Super-Size” at McDonalds) and elsewhere has conditioned us into ordering and eating larger meals as ‘better value for the dollar’, rather than focusing on what is good for us. As our fat intake, as the percentage of our dietary intake, has increased through the years, the subsequent excess fat in our energy intake is stored at a greater rate than carbohydrates or proteins (Hill & Peters, 1998). It may not be this excess intake of dietary fat that promotes obesity, but our increase in overall calories consumed that leads to obesity (Hill & Peters, 1998)

Hill and Peters (1998) show that the current trend is a decrease in physical activity in our daily lives as advances in technology and transportation make our life much easier. The advent of television, and recently computers and video games, has led to an entire generation of children who spend their free time in front of a screen instead of engaging in physical activity for entertainment.

Physical activity promotes fat loss while preserving lean body mass (A Report of the Surgeon General (1996). A very effective form of long-term weight regulation combines physical activity with caloric restriction (A Surgeon General Report, 1996). The consensus amongst researchers today is to favour a healthier overall lifestyle, one which includes physical activity, improved diet, and weight loss promotion (Wickelgren, 1998).

The lessons we learn as children stick with us for the rest of our lives, this lack of physical exercise amongst the last couple of generations of children seems to correspond with the greater prevalence of obesity in society today. Have the children ‘learned’ to be obese by following the lead of adults? Or have the obese children grown into obese adults? Or maybe obesity is an environmental disease we have all been on a ‘timeline’ for since the Industrial Revolution began. Ever since the Industrial Revolution began the population has shown an increasing obesity rate due to the physical ease with which we can now go through life. Now with mainstream media playing up the still unclear role of genetics as the primary role in obesity, men and women have yet to take responsibility for their obesity, preferring instead to blame it on genetics and take the easy way out. Isn’t that how they obesity came to the forefront in the first place? An interesting continuum to be sure.

Chagnon, Y.C., Perusse, L., Weisnagel, S.J., Rankinen, T., & Bouchard, C. (2000). The Human Obesity Gene Map: The 1999 Update. Obesity Research, 8(2), 89-117.

Goran, M.I. & Weinsier, R.L. (2000). Editorial: Role of Environmental vs. Metabolic Factors in the Etiology of Obesity: Time to Focus on the Environment. Obesity Research 8(5), 407-409.

Hill, J.O., & Peters, J.C. (1998). Environmental Contributions to the Obesity Epidemic. Science, 280, 1371-1373.

Samaras, K., Kelly, P.G., Chiano M.N., et al. (1999) Genetic and environmental influences on total-body and central abdominal fat: the effect of physical activity in female twins. Annual Internal Medicine, 130, 873-882

Taubes, G. (1998). As Obesity Rates Risse, Experts Struggle to Explain Why. Science, 280, 1367-1368.

U.S. Department of Health and Human Services. Physical Activity and Health: A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, 1996.

Wickelgren, I. (1998). Obesity: How Big a Problem? Science, 280, 1364-1367.