Myth Blown: Persons with Obesity Have Same Diet as Normal Weight

June 15th, 2011 by MorganDowney Leave a reply »

One of the most pervasive beliefs about persons with obesity is that they eat an unhealthy diet and that persons of normal weight eat a healthy diet. Many, if not most, anti-obesity programs include teaching ‘healthy eating’ as part of their efforts to prevent and treat obesity. Ever since I started working in obesity in the late 1990s, I looked for evidence that the eating patterns of persons who were overweight or obese were different from those at normal weight. I was amazed that there was not any. I was even more amazed that many people  reacted with a “Why even ask?” attitude. They knew it was a given.

Hold on. New evidence indicates that  persons with obesity eat the same diet  as overweight and normal weight persons.

Jim Hill and colleagues looked at changes in consumption from NHANES in 1971-1975 to NHANES in 2005-2006. During this time, obesity increased dramatically. Carbohydrate consumption increased from 44% to 48.7%; fat decreased from 36.6% to 33.7% and protein decreased from 16.5% to 15.7%. But they, for the first time, could look at changes across BMI levels.

The percentage of energy from carbohydrates increased uniformly across both men and women across normal, overweight and obese groups. The percentage of energy from fat decreased uniformly across both men and women across normal, overweight and obese groups. Ditto, decreases in protein consumption. The authors note, “Furthermore, although the percentage of energy from fat has decreased, the total amount of fat consumer has not decreased in the setting of an overall increase in energy intake, primarily from carbohydrates. Even normal-weight men and women consume at least 33% of claories from fat, which could be considered a high-fat diet as absolute fat intake has not decreased but the proportion is smaller because of the overall increase in energy intake. The additional calories from carbohydrates combined with a high-fat diet may only further the propensity toward obesity.” Trends in carbohydrate, fat, and protein intakes a… [Am J Clin Nutr. 2011] – PubMed result

This finding has profound implications in terms of obesity policy. The assumption that obese people eat differently than the rest of the world is a powerful one which has gone unchallenged until now. Of course, this study does not address the quantity consumed nor consumption patterns on BMI levels above 30. Nevertheless, this study should spur researchers to take a closer look at this dietary pattern and its implications for policy.