Don't Worry, Be...Hungry??

Does hunger make you happy? As women – and especially those of us whose metabolism seems to be taking a vacation – we sometimes equate being thin with being happy. But maybe it isn’t just the slender body we look forward to when we reduce calories. Maybe it is that hit of ghrelin.

Ghrelin is a hormone that regulates appetite and rises when we reduce our food intake. Ordinarily, this makes us hungry, so we eat. If we ignore our appetite signal, we produce even more ghrelin, which oddly enough, seems to reduce stress and anxiety. In research done at UT Southwestern Medical Center, ghrelin levels rose when mice were either denied their usual food, or when they were stressed by “bully mice.” As a result, normal mice experienced a decrease in anxiety as the ghrelin level climbed. Mice who were genetically altered not to be able to respond to ghrelin did not show lower stress or anxiety as their levels of the hormone rose. In evolutionary terms it makes some sense that if we are going without food, or if we are stressed by the local tyrannosaurus rex, those who produced a stress reducing hormone would be better able to hunt for dinner or deal with Rex.

So how could this translate into human terms? Well, it may explain why you get hungry when you are stressed, since stress triggers ghrelin production. And it may be a clue why people who are anorexic get hooked on food restriction, since it is possible the increased ghrelin is reducing their anxiety or depression, and reinforcing their low-cal behavior.

And for menopausal women who are struggling with keeping that tummy trim? It makes a case for using both exercise and calorie restriction when getting those pounds off. Not only is that combination the best route to healthy weight loss, but keeping yourself just a little bit hungry may trigger ghrelin production, and reduce your stress and anxiety while you try to fit into a certain dress for your 30th high school reunion. Then again, these studies were done on mice after all, and having written about this I now have an overwhelming urge to pull up a Mars Bar and wait for the human trials.

No, on second thought, I’m going to grab a slice of tomato and wait for the ghrelin to kick in. At the reunion I’ll be the one with the placid smile, looking longingly at the crème brulee.

Photo: Leigh Schindler/Getty Images