Simulating the Influence of Changes in Macronutrient Composition and Amounts in the American Diet From 1971–2008 on Body Composition Changes and Their Contribution to the Obesity Epidemic

Abstract

BackgroundThe obesity epidemic in the US has many suggested causes. We investigated the role that changes in diet macronutrient composition (carbohydrate, protein and fat) and amounts had in contributing to the observed changes in body weight and composition between 1971 and 2008.MethodsUsing a previously validated physiologically‐based mathematical model that simulates the effect of dietary macronutrient composition and amounts on body weight and composition changes in sedentary men and women, we simulated body weight changes from 1971 through 2008 based on dietary macronutrient composition and amounts reported from NHANES and the Centers for Disease Control and Prevention (CDC).ResultsSimulated body weight change patterns for both men and women were similar to those actually observed, though body weight values for men were generally over‐predicted and for women were under‐predicted. Final simulated body weights for men and women were +9.3% and −10.4% actual reported values, respectively.ConclusionsWe conclude that the obesity epidemic has been predominantly driven by the amounts and types of consumed macronutrients in food, and that if the American diet were to return to pre‐epidemic macronutrient levels and composition the obesity epidemic would likely reverse and disappear.