A study from the University of Copenhagen shows that the hormone neurotensin may help predict whether people are able to maintain weight loss. The proof-of-concept study is the first time that the hormone has been investigated in relation to weight loss induced by a low-calorie diet.
"Initially, we examined the effect of weight loss in obese mice and concluded that weight loss led to decreased amount of the hormone neurotensin. Subsequently, in a clinical study we found that weight loss also led to a decreased amount of neurotensin in humans,” explained Professor Signe Sørensen Torekov, who is last author of the study, at the Department of Biomedical Sciences at the University of Copenhagen. “Interestingly, people who maintained weight loss released more neurotensin than people who regained weight again. It may help explain why some people are more successful than others at maintaining weight loss."
The gut derived anorexigenic hormone neurotensin (NT) is upregulated after bariatric surgery which may contribute to the sustained weight loss. In contrast, diet-induced weight loss is most often followed by weight regain. Therefore, the researchers investigated whether diet-induced weight loss impacts levels of circulating NT in mice and humans and whether NT levels predicts body weight change after weight loss in humans.
In humans, similar to the mice, the low-calorie diet induced weight loss of 13% body weight was associated with 40 % reduction in fasting plasma NT levels (p < 0.001). Meal-induced NT peak responses were greater in humans who lost additional weight during the one-year maintenance phase, compared to participants who regained weight (p<0.05).
The researchers concluded that the people who lost even more weight in the year following the diet released more neurotensin than people who gained weight after completing the diet.
"It is an interesting result. You can speculate whether the people who put on weight again simply lack the appetite-inhibiting effect which neurotensin appears to have," added Torekov. “Another interesting thing about studying these appetite hormones is to learn how humans may respond to potential treatment and especially the combination of several appetite hormones to maintain weight loss.”
"We know that other gut hormones, released in greater amounts after obesity surgery, help explain why people who have undergone obesity surgery are able to maintain weight loss. But no one had studied the role of neurotensin in connection with diet-induced weight loss," added PhD student, Joachim Holt, who is first author of the study.
"When researchers first discovered leptin, a key hormone in weight regulation, they learned that amounts drop during weight loss. This could indicate that increasing the amount of leptin in the body would cause people to lose weight," said Torekov. "But it turns out that people who live with obesity are leptin resistant, which means that they do not respond with weight lose to the hormone. We do not know whether this also applies to neurotensin. So we still have a lot of work ahead of us."
The outcomes were reported in the paper, ‘Increased meal-induced neurotensin response predicts successful maintenance of weight loss—Data from a randomized controlled trial’, published in Metabolism. To access this paper, please click here