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The activity in a cortical area involved in self-regulation was the best correlate of weight loss in a study published today (October 18) in Cell Metabolism.
Previously, scientists thought that challenges to losing weight stemmed from imbalances between the hormones leptin, which produces a feeling of satiety, and ghrelin, which stimulates hunger. When people go on a diet, ghrelin levels go up and leptin levels go down.
To see how brain activity fits into dieting physiology, Alain Dagher, a neurologist at McGill University, worked with 24 overweight and obese people who were starting a 1,200-calories-per-day diet at a weight-loss clinic. Before starting the regimen, participants had fMRIs—imaging scans that show brain activity—while looking at pictures of either appetizing, sometimes high-calorie food, or of scenery. The researchers repeated the scans one month and three months into the diet.
Typically, food pictures activate the ventral medial prefrontal cortex, ...
