A study just published in the American Journal of Clinical Nutrition found that foods containing a high glycemic index (a.k.a. heavily processed foods) trigger hunger and craving faster than low-glycemic foods.
The subjects, 11 obese and overweight men ranging in age from 18 to 35 years old, were given two liquid meals with nearly identical calories, palatability, and macronutrient composition. The only difference was the form of sugar used – the high-glycemic meal contained light corn syrup and lactaid milk whereas the low glycemic-index meal contained cornstarch and 1% milk.
The results were astonishing – consumption of high-glycemic meals increased brain activity in regions of the brain associated with reward and craving. Those individuals who consumed high-glycemic meals also experienced a significant decline in blood glucose, which triggered hunger faster.
In concluding, the authors state, “These neurophysiologic findings, together with longer feeding studies of weight-loss maintenance, suggest that a reduced consumption of high-GI carbohydrates (specifically, highly processed grain products, potatoes, and concentrated sugar) may ameliorate overeating and facilitate maintenance of a healthy weight in overweight and obese individuals.”