Diet While You Sleep…Literally

People on a diet are given a mountain of advice:

“Keep a food journal”

“Watch out for carbs”

“Eat a really big breakfast”

Brand new research from universities from around the world are suggesting that one of the best pieces of diet advice should be:
“Sleep in”

Body Weight and Sleep: What’s The Connection?

Study after study over the last decade have clearly shown this connection: the less you sleep, the heavier you tend to be. In fact, one enormous study had over 1.1 million participants (yes that’smillion). That study found a direct and independent correlation between high BMI (body mass index) and sleeping less than 7 hours per night.

A researcher in this area, Dr. Patricia Prinz states: “There is a well-documented relationship between short sleep duration and high body mass index.”

How Can Staying Up Late Make You Gain Weight?

Years ago, I remember discussing this research with a colleague of mine from the University of Rhode Island. Her explanation of this phenomenon was: “Of course people who sleep more will be thinner-when you sleep you aren’t eating.”

Although she has a point, scientists have other explanations.

They point to two important hormones in our body that make a huge impact on our appetite: Ghrelin and Leptin.

30 Second Crash Course on Ghrelin and Leptin

Ghrelin is one of about a hundred appetite controlling hormones produced by your stomach. As ghrelin levels rise, you get hungrier. As they fall, you get more full. If you are trying to lose weight, doing things to keep ghrelin low will go a long way in curbing your appetite.

Leptin, on the other hand, is made by your fat cells. Although extensively studied, leptin’s role in weight gain is not entirely understood. Once thought to be a “holy grail” treatment for weight loss, leptin is now known to be a less important regulator of metabolic rate and appetite. In general, leptin does the opposite of ghrelin-it tells your body that you’re full.

What Does Sleep Have To Do With Ghrelin and Leptin?

A recent study tested ghrelin and leptin levels in about a 1,000 people. They separated the subjects into those that slept “enough” (>8 hours) or didn’t sleep “enough” (<8>

They found that the people who slept less than 8 hours had more ghrelin (the one that increases appetite) and less leptin (the one that decreases appetite) floating around in their bodies than those that slept enough. They also weighed both groups and found what other studies have also found: less sleep=more weight.

The research is telling us that when you stay up late to watch the Oscars, your body responds by making more ghrelin and less leptin.

A Warm Glass of Ghrelin Before Bed…

Apparently, your body has good reason to be shooting out all of this ghrelin after pulling an all-nighter: ghrelin makes us sleep better.

When researchers inject ghrelin in someone at bedtime, they tend to have increased REM (and therefore restful) sleep. The increase in circulating ghrelin seems to be evolution’s method of getting us to get back on track with our sleeping patterns. Although effective, it has an unintended side effect: making us hungry.

Hitting Snooze To Lose Weight

The next time you are having a dream about your new and improved body, remember: that may be your bodies way of telling you that you’re doing the right thing.

Brian Dean MS, RD is a registered dietitian and researcher. After years of research, Brian has set his sights on helping those with lower back pain. He serves on the Medical Nutrition Committee for The American Society for Nutrition and is a professional member of numerous research organizations including the International Association for The Study of Pain, American Chronic Pain Society, and The American Dietetic Association. He recently created a research-based lower back pain treatment program called The Back Pain Diet which is available from his website Stop Lower Back Pain.