Losing weight may have perks that go beyond looking better, feeling better, improved health and better mobility. It can improve your body’s insulin sensitivity, reduce belly fat and contribute to your cardiometabolic health. Weight loss does this by raising a dieter’s levels of ghrelin, the “hunger hormone,” a new study suggests.

Ghrelin is a hormone produced in our gut, primarily in the stomach. It is nicknamed the “hunger hormone” because it stimulates appetite and increases the amount of food we eat.

Dieting led to an increase in fasting levels of ghrelin which resulted in the loss of belly fat and improved insulin sensitivity, theoretically reducing the person’s risk of diabetes or other metabolic diseases.

Levels of ghrelin are mostly regulated by when we eat. Before eating and when fasting, levels increase, and after we eat, levels of the hormone go down. The timing of rises and falls in our ghrelin level depends on our eating routine, so the hormone is believed to play a role in our growling stomachs and feeling the need the eat.

Clinical trial data on nearly 300 people who had either dyslipidemia or abdominal obesity were used in an 18-month study of ghrelin levels. Researchers at Ben-Gurion University in Israel and the Harvard T. H. Chan School of Public Health had participants follow one of three diets combined with physical activity. One group followed the Mediterranean diet. Another followed a green version of the Mediterranean diet that omitted red meat but included green tea (3-4 cups/day) and a Mankai plant (a leafy vegetable) green shake. The third group's diet was based on healthy dietary guidelines.

Fasting ghrelin levels were twice as high in people on the green-MED diet compared to participants who followed the traditional Mediterranean diet, even though calorie restrictions and weight loss were similar.

Dieting led to an increase in fasting levels of ghrelin, and that increase resulted in the loss of belly fat and improved insulin sensitivity, theoretically reducing the risk of diabetes or other metabolic diseases.

“The results of our study suggest that fasting ghrelin is an essential hormonal factor in the diet-associated recovery of sensitivity to insulin and visceral adiposity regression, or reduction in belly fat,” Gal Tsaban, of Ben-Gurion University of the Negev and Soroka University Medical Center, said in a statement.

The reason behind the diet-specific elevation in fasting ghrelin levels is not yet clear. It could be the result of some other mechanism in a dietary regimen that lowers cardiometabolic risk, Tsaban suggested, such as was seen with the green-MED diet.

The study is published in the Journal of Clinical Endocrinology & Metabolism.