Is agriculture responsible for obesity?

An article by Bruce M. King in the February-March 2013 issue of The American Psychologist indicates 502 million persons worldwide are obese (i.e., a body mass index greater than 30, calculated by weight in kilograms divided by height in meters, squared). Another billion of the world’s population of seven billion people are overweight.

A 2010 survey of 4,111 U.S. residents by Cynthia L. Ogden and her associates reported that 35.7 percent of adults and 16.9 percent of children were obese. Another third of American adults were overweight and 16 percent more children were overweight.

In his popular 2006 book, The Omnivore’s Dilemma, Michael Pollan blames the industrial food chain, particularly corn, for influencing American tastes and imparting our diet with too many starches. Corn is part of most dairy products, meats, soft drinks, snacks and many other foods and beverages.

Is the industrial food chain at fault? A 2011 Lancet article about worldwide obesity by Boyd A. Swinburn and his colleagues states: “The simultaneous increases in obesity in almost all countries seem to be driven mainly by changes in the global food system, which is producing more processed, affordable and effectively marketed food than ever before.”

“This passive overconsumption of energy leading to obesity is a predictable outcome of market economies predicated on consumption-based growth.”

Whoa! Is this the whole story? While a good argument can be made that a ready supply of skillfully marketed energy-rich foods contributes to obesity, additional factors are involved.

Our behaviors and genetic make-up also contribute to obesity. Choosing what and how much to consume, as well as exercising to burn calories, are behaviors that are largely under our control.

We are still in charge of what we eat and drink. A growing number of careful shoppers read labels on processed foods in the grocery stores and request caloric counts in restaurants to select items that are healthy and low in sugars and fats.

Work has become more sedentary as machinery and technology have eased physical labor requirements. We have to replace the physical activity lost because of office-bound work with other ways to use up calories.

Active recreation, working out at the gym or elsewhere and finding ways to make work routines more energy-consuming (e.g., taking the stairs instead of the elevator) can offset low activity work.

It is now common to observe farm residents walking, riding bikes or jogging on countryside roads and trails. A generation ago when we spotted a neighbor walking alongside a road we stopped to offer the neighbor a ride, but no longer.

Our genetics play an important role in obesity. Dr. King’s recent article in The American Psychologist states, “The prevalence in obesity in the United States has doubled since 1980.”

“The increase in the prevalence of obese and overweight individuals has happened too rapidly for it to be due to an alteration in the genome.”

Dr. King suggests our body systems that regulate taste and smell were gradually developed over the preceding two million years and were highly useful to our hunter-gatherer ancestors who relied heavily on these senses to locate food.

Hunter-gatherers were accustomed to gorging on food when available because they might have to endure periods of deprivation when palatable food could not be found. Accumulating fat for lean periods had survival value.

Agriculture changed our food consumption. When farming and raising livestock began to be undertaken some 15,000 years ago, our diets changed, but not our consumption habits. We were still accustomed to gorging on nutrient-dense foods because they gave us satisfaction.

Raising grains and fattening livestock on pastures gave agrarians ample food and reduced the need to sometimes traverse long distances to find foods. Many of the calories that agriculturalists produced were stored in our bodies as fat, as well as in granaries, livestock and substances such as beer and other alcoholic drinks.

Dr. King elaborates: “Brain reward circuitry that was acquired during evolution to seek out and eat as many nutritionally high-dense foods as possible is able to overrule the physiological inhibitory mechanisms that were designed to limit meal size and weight gain.” Sometimes we eat even when satiated.

In short, we are predisposed to eat and drink more than we need to exist. That doesn’t mean we can’t control ourselves.

As highly intelligent and rational beings we have the capacity to make healthy choices about what we consume, how much, and how we use up calories. We are responsible for managing the influence of the industrial food chain on our lives.

Dr. Rosmann resides on his Harlan, Ioaw farm. Contact him at: http://www.agbehavioralhealth.com.