Wendy Xu Xu 1
TSM 311
5 April 2013
America is becoming one of the World’s Fa“est Na$ons: What Causes Obesity?
Fast food can cause adverse health problems if we consume it on a daily basis, but is it
the only cause of obesity? Several con,ic$ng causes are working at this debate. Obesity is
defined as having a Body Mass Index of greater than 30 or above the 95th percen$le. The need
to /gure out the exact cause of obesity is apparent, and researchers have been trying to figure
out an answer to this question for years. Obesity has reached widespread proportions in the
United States and is threatening to become a global epidemic if the trend con$nues. According
to the sta$s$cs established by the World Health Organiza$on, 54% of U.S. adults are overweight
and 22% of the population is obese[ CITATION Jam98 \l 1033 ]. Currently, the fa”est state is
Mississippi, with 32.5% of adults overweight or obese.
The question remains, however, is how much of the overweight and obesity is caused by
eating fast food and how much is caused by the lack of physical activity. Although there has
been some very advanced recent progress in finding the genetic mechanisms that cause obesity,
researchers have a long way to go in explaining the high heredity of obesity. Some proponents
could claim that fast food could be the cause of obesity. This could be proven in the
documentary Super-Size Me; when Morgan Spurlock gained 24.5 and his cholesterol shot up 65
points a@er the thirty days McDonald’s frenzy. Morgan Spurlock was perfectly healthy with
normal cholesterol and weight before star$ng his McDonald’s frenzy. His girlfriend was a vegan
chef and cooked him healthy food every day. This is particularly a complicated and
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controversial issue because there are so many possible causes of obesity not directly related to
the environment such as genetic factors. Although human body systems have excellent physical
mechanisms to defend against body weight loss, they have weak mechanisms to defend against
weight gain [ CITATION Jam98 \l 1033 ].
To /nd an answer to this question on what causes the widespread epidemic obesity,
trials have been conducted with the eBect on physical inactivity and eating fast food.
Researchers have sampled foods sold for immediate consump$on in takeout restaurants, fast
food places, and other supermarkets. Food consumed outside the home accounted for 34% of
the food budget in 1970 has increased to 47% by the 1990’s [ CITATION Jam98 \l 1033 ]. While
eating too much fast food alone is not the only cause of obesity, there are many other factors
that cause obesity such as genetic factors and lack of exercise and physical inactivity. Though
there are many factors that cause obesity, the major cause of obesity is the lack of physical
activity and food portion sizes increasing in the past twenty years.
More children and adults are overweight than ever before and the numbers are growing
at an alarming rate. The alarming increase is most prevalent among today’s youth with more
than 25% of the US children overweight or obese[ CITATION Jam98 \l 1033 ]. Children who are
obese have an 80 percent chance of being obese when they are adults. Studies show that the
current trend of obesity is caused mainly by an environment that promotes excessive food
intake and discourages physical activity. Data has indicated that marketplace portions of foods
sold for immediate consumption that are major contributors of energy to the US diet have also
increased signi/cantly. Fast food portion sizes have been made worse with McDonald’s having
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the option to “supersize” their menu options. Fast food chains such as McDonald’s, Burger King,
and Pizza Hut are everywhere such as amusement parks, shopping areas, airports, gas sta$ons,
and even hospitals.
In the American Journal of Public Health, “dietary intake surveys indicate a per capita
increase from 200 kcal/day in 1977-1978 to 500 kcal/day more than the 1970s” [ CITATION Lis02
\l 1033 ]. This sta$s$c shows that Americans are consuming more than they did in the past
thirty years and food portion sizes have been increasing. Manufacturers of fad diets such as
Lean Cuisine and Weight Watchers adver$se larger portion sizes for frozen meals. Americans eat
more than they did in the past thirty years because they need more energy to do work. The
reason that
restaurant portion sizes are increasing is because large sizes not only encourage consumers to
eat more but also make it more diMcult for them to burn the amount of calories with physical
activity. With the excep$on of sliced white bread, all of the commonly available food portions
have exceeded greatly in size [ CITATION Lis02 \l 1033 ].
Obesity can cause a shrew of health problems in the future if the trend con$nues.
According to the OMcial Journal of the American College of Sports Medicine, “overweight and
Obese people are directly linked to increased risk of chronic diseases such as heart disease,
hypertension, diabetes, and impaired physical function [ CITATION Ste99 \l 1033 ]. The most
common eBects of obesity are heart disease and diabetes, but there are a lot of other ways in
which it could harm one’s health. Heart disease is the nation’s number one killer, and the rates
of diabetes and obesity have risen in recent years. Carrying too many pounds may lead to
certain types of cancer, arthri$s, sleep apnea, and even infer$lity [ CITATION Lau13 \l 1033 ]. It
could also lead
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to mental health problems and psychological issues such as depression and low self-esteem.
Physical activity and cardiorespiratory fitness are often inversely associated with similar risks. In
observa$onal studies both overweight and obesity is directly related physical activity and
cardiorespiratory fitness with sedentary and un/t people having greater weight for height, body
mass index, and percent body height [ CITATION Ste99 \l 1033 ]. Data from subsequently
conducted trials have indicated that increases in physical activity which results in weight loss
and changes in body composition and fat distribution [ CITATION Ste99 \l 1033 ]. This sta$s$c
shows that the overweight and obesity is caused by sedentary and inac$ve lifestyles.
