Hormones and hunger: the effect of ghrelin

Written by: Professor Barbara McGowan
Published: | Updated: 26/11/2020
Edited by: Top Doctors®

The gut-brain axis plays a crucial role in appetite control. Circulating gut hormones send signals to the brain to inform whether we feel hungry or full. Ghrelin, our hunger hormone, is secreted by the stomach just before meal times to signal that we feel hungry. After meals, satiety hormones such as GLP-1 and PYY are secreted by the intestine to signal to the brain that we feel full. In people with obesity, some of these gut hormone responses are impaired and may contribute to their obesity.

The problem with losing weight

When we attempt to lose weight through dieting, our gut-hormone response leads to increases in ghrelin and decreases in our satiety hormones. This is the body’s way of telling the brain that we have lost weight and we must fight to regain the calories lost. Furthermore, when we lose weight, our basal metabolic rate, the energy required to keep our basic metabolic processes ticking, is lower, that is we need to eat less calories to maintain the new body weight. These lower energy requirements, together with gut hormone response, are some of reasons to explain the challenges of weight loss maintenance.

Combining lifestyle change and medication

Lifestyle and dietary changes are the cornerstone of any dietary loss programme, but diet alone may not be enough when trying to maintain weight loss long-term. New pharmacotherapies are now available for the treatment of obesity. Medication can mimic the action of the satiety hormone GLP-1 and works by decreasing appetite through its action on the brain. Clinical trial data show that obese patients can achieve a mean weight loss of 8% in one year, although patients with an early response can achieve more. For patients with prediabetes, medication can reduce the incidence of developing type 2 diabetes over 3 years. These gut-hormone therapies are promising and effective treatments in the fight against obesity and related co-morbidities.

By Professor Barbara McGowan
Endocrinology, diabetes & metabolism

Based in London, Professor Barbara McGowan is a leading expert in endocrinology. Her special interests include weight loss, bariatric medicine, polycystic ovarian syndrome, thyroid problems, infertility, adrenal disease and pituitary disorders.

Outside of her clinic she is dedicated to research, her work has been recognised by NIHR/RCP who awarded her for her 'outstanding contribution to research' in 2016.

She has published extensively in high impact journals, including the Lancet and New England Journal of Medicine. She practices from Guy's Hospital and BMI Bishops Wood while also serving as an Honorary Professor at King's College London.

View Profile

Overall assessment of their patients

This website uses its own and third-party cookies to collect information in order to improve our services, to show you advertising related to your preferences, as well as to analyse your browsing habits..