Why high protein diets suppress hunger

A recent study, published in the Journal of Clinical Endocrinology & Metabolism has helped us to understand why some diets have more potential for weight loss than others. Researchers, led by Karen Foster-Schubert of the University of Washington School of Medicine in Seattle, Washington, examined the relative ability of different nutrient types to suppress ghrelin, which is secreted by the stomach and is the only known appetite-stimulating hormone. Circulating ghrelin levels increase shortly before meals and then decrease promptly after ingestion of food.

They found that eating protein resulted in the greatest suppression of ghrelin over a long period and, interestingly, consumption of carbohydrates resulted in a strong ghrelin suppression initially, although subsequent ghrelin levels rebounded well above baseline.

Study participants were given three drinks with widely different proportions of carbohydrates, fats and proteins. Ghrelin levels were measured every 20 minutes for six hours afterwards.

This suppression of ghrelin may be the basis for the apparent success of high protein, low fat and low carbohydrate diets in stimulating weight loss.