Excess weight is commonly understood to be caused by an energy imbalance—more calories consumed than expended over the course of the day. A new study co-authored by researchers from Harvard T.H. Chan School of Public Health argues that this framework is incorrect. In its place, the authors propose a carbohydrate-insulin model (CIM) for understanding obesity. According to the CIM, obesity is the result of a dysregulated hormonal and metabolic response to the carbohydrates people eat.
The study was published September 13, 2021, in The American Journal of Clinical Nutrition.
Co-author Gary Taubes, a science and health journalist, described the CIM model in a September 13 opinion piece in STAT: “People don’t get fat because they eat too much, consuming more calories than they expend, but because the carbohydrates in their diets—both the quantity of carbohydrates and their quality—establish a hormonal milieu that fosters the accumulation of excess fat.”
The authors recommend substituting carbohydrates with a high glycemic load (a measure of their impact on blood sugar) like refined grains, potato products, and sugary foods with high-fat foods such as nuts, seeds, avocados, and olive oil, which have no impact on blood sugar.
Read STAT opinion piece: How a ‘fatally, tragically flawed’ paradigm has derailed the science of obesity