It’s the second to last day of SFN. Sci thought she was a grad student of boundless energy, but even she is beginning to feel…a little burned out. Posters, each one of the good and showing some seriously cool stuff, slide past her eyes. After a while you can barely remember what you just saw, even though you desperately want to, because you know you would never have seen it had it not been terribly cool. But at a conference this big, with so many people, it’s hard to remain “on” all the time, to ask the brilliant questions, to give the perfect presentation.
But press on we must! SFN comes only once a year. It’s like neuroscience Xmas! You have to soak in every inch of the experience. And even through your fog of exhaustion (and possibly your fog of hangover), there are some posters that stick out at you. Some that are elegant and interesting, no matter how tired you are:
*D. E. PANKEVICH, G. SMAGIN, T. L. BALE; Animal Biol, Univ. Pennsylvania, Philadelphia, PA; AstraZeneca, Wilmington, DE “Caloric restriction reprogramming of stress and reward neurocircuitry increases vulnerability to stress-induced binge eating”
As we all know, people in the US have a…concern with our weight. We might think we are too fat, or we are too thin, or that people in the US are too fat, or that we have unrealistic expectations of body shape and size. Regardless of which opinion you have, thinking about weight and diet takes up a LOT of American life, from the commercials we see to the amount we try to get to the gym.
And of course, Americans think a lot about diet. It seems that Sci cannot go a day without hearing about the Zone diet, the volumetrics diet, Weight Watchers. Sci herself writes down her food consumption, and worries far too much about what she’s putting in to her body. It seems like everyone is forever going on a diet. I hear endless stories about the grapefruit diet, the Atkins, the Zone. I hear about the new Caloric Restriction phenomenon, where you are supposed to restrict your calories by 25% and prolong your life (something which is currently in clinical trials and was featured recently in the NY Times). Caloric restriction seems interesting. It might be able to prolong your life, to make you healthier. But is it all good? Are diets good? And what IS it about diets that makes you immediately crave those awful foods you shouldn’t have, even when you know that you wouldn’t crave them, if only you weren’t on a diet?
Of course there’s a way too look at this. In this case, the authors of the study used rats, and put them on a diet. Not anything too severe, just restricting them abut as much as someone in those new “Caloric Restriction” diets. But then, they took these newer, svelter rats, and exposed them to stress, looking at how they responded.
And the results…well. When rats are on a diet, and exposed to stress, it turns out that they eat their feelings. They binge eat a lot more than rats that had not previously been on a diet. This seems like a simple finding, but it shows something very important. It shows one of the reasons that “yo yo” dieting may be so harmful, and it shows one of the many ways in which stress can disrupt your diet. In particular, it wasn’t just an increase in regular food intake in these rats, it was an increase in palatable food intake. These rats ate oreos (well, the rat equivalent of oreos, which is a high fat diet and very tasty to them) like they never ate them before. This shows that caloric restriction, though it might provide health benefits, may also be enough of a stressor to…stop your caloric restriction, making you more likely to binge eat and possibly less likely to stay on your diet.
Well, sure, you might think. Big news there. Of course when I’m on a diet, I crave oreos, because I know that I can’t have them. Why do this in rats? Well, for several reasons. Doing this study in rats shows that the binge eating and cravings experienced in animals on a diet isn’t a social thing for humans. It doesn’t require conscious thought on our part, and in fact, may be due to some pretty basic drives. Not only that, when we study diet and binge eating in rats, we can look at their hormone levels, how they process food, and how they process signals of when to stop eating, which are things we cannot yet really investigate in humans. And finally, keeping humans on a caloric restriction is HARD. They tend to cheat.
So this relatively simple study could reveal, in the end, some very important things about how we process food cravings and how what we are currently eating changes our responses to simple things like stress. And it makes it more obvious that stressing out AND being on a diet is a recipe for an oreo disaster.