Nutrition Science and Everyday Application - beta v 0.1

OBESITY EPIDEMIC: CAUSES AND SOLUTIONS 409
Figure 7.20. Some elements of our environment that may make it easier to gain weight include
sedentary jobs, easy access to inexpensive calories, and cities built more for car travel than for
physical activity.
Our jobs have become more and more sedentary, with fewer opportunities for nonexercise
thermogenesis (NEAT) throughout the day. There’s less time in the school day for
recess and physical activity, and fears about neighborhood safety limit kids’ ability to get out
and play after the school day is over. Our towns and cities are built more for cars than for
walking or biking. We can’t turn back the clock on human progress, and finding a way to stay
healthy in obesogenic environments is a significant challenge.
Our environments can also impact our food choices. We’re surrounded by vending
machines, fast food restaurants, coffeeshops, and convenience stores that offer quick and
inexpensive access to calories. These foods are also heavily advertised, and especially when
people are stretched thin by working long hours or multiple jobs, they can be a welcome
convenience. However, they tend to be calorie-dense (and less nutrient-dense) and more
heavily processed, with amounts of sugar, fat, and salt optimized to make us want to eat
more, compared with home-cooked food. In addition, portion sizes at restaurants, especially
fast food chains, have increased over the decades, and people are eating at restaurants
more and cooking at home less.
Poverty and Food Insecurity
Living in poverty usually means living in a more obesogenic environment. Consider the fact
that some of the poorest neighborhoods in the United States—with some of the highest
rates of obesity—are often not safe or pleasant places to walk, play, or exercise. They
may have busy traffic and polluted air, and they may lack sidewalks, green spaces, and
playgrounds. A person living in this type of neighborhood will find it much more challenging
to get adequate physical activity compared with someone living in a neighborhood where it’s
safe to walk to school or work, play at a park, ride a bike, or go for a run.
In addition, poor neighborhoods often lack a grocery store where people can purchase
fresh fruits and vegetables and basic ingredients necessary for cooking at home. Such areas
are called “food deserts”—where healthy foods simply aren’t available or easily accessible.
Another concept useful in discussions of obesity risk is “food insecurity.” Food security
means “access by all people at all times to enough food for an active, healthy life.” 8 Food
insecurity means an inability to consistently obtain adequate food. It may seem counterintuitive,
but in the United States, food insecurity is linked to obesity. That is, people who
have difficulty obtaining enough food are more likely to become obese and to suffer from
diabetes and hypertension. This is likely related to the fact that inexpensive foods tend to be
high in calories but low in nutrients, and when these foods form the foundation of a person’s