There are lots of hormones involved in how we eat and whether we gain or lose weight. There are ghrelin and leptin, the hormones of hunger and satiety; there’s insulin with its influence over blood sugar; and there are glucocorticoids like cortisol impacting your metabolism, to name just a few. A less known contributor is neuropeptide Y (NPY).
We’ve only known NPY exists since the 1980s, but it has a role in all sorts of the body’s systems, from controlling seizures and reducing anxiety to improving heart health and changing how we react to alcohol. It also seems to play a prominent role in appetite and fat, with obese people apparently having higher NPY levels (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1642692/) (https://pubmed.ncbi.nlm.nih.gov/26156739/) (https://pubmed.ncbi.nlm.nih.gov/30678628/).
When the NPY in our brains and nervous systems goes up, often as a response to stress or fasting, we eat more. That’s going to have an impact on our weight. On top of that, NPY has a powerful influence on our fat tissue. It encourages our body to store more fat, potentially manifesting as obesity. Weight alone doesn’t always indicate health, but the portion of that weight that is fat is significant.
Hormones may play a prominent role in weight, fat and appetite, but that isn’t always helpful when you’re trying to shed some pounds. You can’t exactly just switch your hormones on and off at will. NPY is one of the ones where we’re still figuring out how it works, and you can’t just take a supplement to bring it under control.
The best advice we can give is the advice pretty much every health professional always offers. Exercise regularly, and try to eat a balanced and nutritious diet. Some research suggests that exercise helps bring NPY under control, but other studies don’t seem so sure. There’s a little bit of evidence that lots of fat and sugar in your diet can drive NPY up, and we’re always recommending you control your fat and sugar intake anyway.
Understanding that we can’t control everything that contributes to obesity is important, even if it means you don’t start losing weight. It may help you set more realistic expectations for your own body and counteract some of the despair that may accompany continued failed attempts. Control what you can, accept what you can’t, and you’ll soon have a healthier perspective on fat loss.