There is an obesity crisis in America, 18.5% of children and 39.6% of adults are obese as of 2016. The rates of obesity are rising.

Obesity is associated with heart disease, some cancers, stroke, and type 2 diabetes among others. It is creating a national health crisis and is quite costly.

While obesity has been rising for all socioeconomic groups, it is hitting lower socioeconomic groups harder than others. In general, in the U.S., income is inversely related to obesity:

The above chart shows obesity levels broken down by households with various percentages of the Federal Poverty Level. The poverty level in 2014 for a household of four people was $23,850. 400% of the poverty level was $95,400.

Here is an amazing fact: in 1990 and prior years obesity did not vary by income! Only in the last 30 years has obesity stratified according to income.

Obesity also correlates with education level.

Obesity also varies by race and gender:

Rural counties have higher obesity than suburban and urban counties.

Why Does Obesity Vary by Income, Race and Education?

Obesity is a very complex topic and solutions to it have no easy answers. Possible “whys” with regard to variations in the different concentrations in obesity are quite interesting and shed light on causes and solutions to obesity. Here are some of the potential causes of the differences:

Food Availability and Food Deserts:

• Higher calorie food is often cheaper than lower-calorie food. It’s cheaper to buy a bag of chips than a few apples.
• Lower socioeconomic neighborhoods typically have less access to healthy restaurants and grocery stores.
• Neighborhoods with high concentrations of black and Hispanic individuals have been found to have more fast-food restaurants per-capita.
• A study from 2011 found that “the opportunity to move from a neighborhood with a high level of poverty to one with a lower level of poverty was associated with modest but potentially important reductions in the prevalence of extreme obesity and diabetes.” The exact mechanisms were not investigated.

The “Insurance Hypothesis”: “Under the Insurance Hypothesis, individuals should store more fat when they receive cues that access to food is uncertain. Poor people in high-income countries receive such cues, as they experience more stress and greater existential risk for multiple reasons. Prominent among these risks is malnutrition, yet empty calories are still inexpensively available as processed foods and sugar-sweetened beverages.”

Social Influence:

• Studies have found that obesity spreads through families and social networks. ” When one person gains weight, close friends tend to gain weight too.”
• Similarly, an interesting study in the New England Journal of Medicine looked at various sedentary leisure activities such as reading, going to movies, attending cultural events, attending sporting events, watching TV, listening to music, and socializing with friends. None of these events burn many calories, yet “participation time in cultural activities is associated with lower rather than higher body weight.” In other words,”highbrow activities” such reading and going to art museums was associated with lower body weight and “lowbrow activities” like watching TV and going to sporting events was associated with higher body weight. According to the study: “The activities are spuriously yet still meaningfully associated with body weight through a possible common cause – cultural tastes that in part distinguish socioeconomic status-related group membership.” So, to be in an upper social class, there is pressure to be thinner and engage in highbrow activities.

Less Physical Activity: As our society has moved from agrarian and factory-oriented to office jobs, we burn less calories and are less active. This leads to increased obesity. Thus, for many people, exercise must occur outside of work hours. Access to gyms and outdoor areas suitable for exercise outside of work hours vary greatly based on neighborhood and socioeconomic environment. According to the Robert Wood Johnson Foundation “low-income communities are far less likely to have healthy food, parks, and green spaces available to them and are four and a half times less likely to have recreational facilities such as pools, tracks, tennis courts, and sports fields.”

Advertising Disparity: According to the Robert Wood Johnson Foundation “food and beverage companies disproportionately target advertising for many of their least nutritious brands, including fast food, candy, sugary drinks, and snacks to Black and Latino youth.”

An interesting chart of different possible factors contributing to obesity: