The obesity epidemic in the US is due solely to increased food intake

I recently read an article by Fran Lowry on heartwire reporting on research presented at the 2009 European Congress on Obesity in Amsterdam. The research showed how the increased amount of food Americans eat is the cause of the obesity epidemic not the lack of physical activity. This idea runs against the current assumption that our increasingly sedentary lives are to blame for the weight gain.

“If Americans want to get serious about winning the battle of the bulge, they are going to have to cut down on the amount of food they eat, Swinburn, who is director of the World Health Organization Collaborating Centre for Obesity Prevention, told heartwire.” Swinburn and his colleagues created a series of equations to take into account energy intake, energy expenditure, and body size for a group of 963 children and 1399 adults. They used USDA food-supply data and then predicted the increase in weight in the children and adults between 1971 to 1976 and between 1999 and 2002. If the predicted weight matched the observed than it was food consumption, otherwise it was the change in physical activity. The children’s gain of 4.0 kg was attributed to calorie consumption. The adults predicted 10.8 kg was higher than the observed of 8.6 kg showing that physical activity may have moderated the weight gain somewhat. This study clearly shows that controlling what and how much we eat is going to have a much greater impact on weight gain/loss. It is important not to loose sight of the benefit of exercise and physical activity as there are a number of physiological benefits. Exercise allows us to do the activities we love whether it is chasing the kids, climbing a mountain, or dominating at the Sunday flag-football game.

The bigger challenge to creating awareness is fighting the driver of this overconsumption, the food industry. The easy approach for politicians and the food industry has been promoting physical activity as the solution to obesity, said Swinburn. "It's relatively uncontroversial, there are no commercial competitors, it's a positive thing to do, so politicians, egged on by the food industry, heavily promote the physical-activity side of the equation." The food industry has also mastered promotion, especially to the most vulnerable and impressionable members of society—children. "Over the past 30 years they have become very sophisticated in marketing and advertising that is particularly iniquitous in relation to kids. They are adept in the way they turn kids into liking, preferring, demanding, and pestering for the foods that they advertise."

The American College of Cardiology spokesperson Dr Matthew Sorrentino (University of Chicago), agreed that Swinburn and colleagues verified what experts in the obesity field had long suspected. "The main cause of the obesity epidemic in this country is the wide availability of high-caloric foods and the fact that we are eating way too many calories in the course of a day. Exercise has much less impact." Sorrentino said that about 90% of weight loss is achieved by cutting calories; only about 10% of weight loss is achieved by significantly increasing physical activity.

The take away from this study is to focus on what we can control, which is what goes in our mouths. This study does not mean that we should become anorexic and sit on the couch. Instead focus on eating whole, unprocessed, unrefined foods (lots of veggies) like the way grandma used to make. It is still important to increase the exercise as this will help with a whole host of things (we’ll save that for another blog) beyond just weight loss. Next time you crave that double double cheese burger with a soda…remember that you will have to run for an hour to burn the calories. Simply prevent that weight gain by opting for the low-cal alternative with tea/water and skip the extra 700 calories.