One piece of advice that all dieters receive is simply this: don’t skip breakfast. The idea is that skipping breakfast will make you crave junk food, and bypass eating the healthy stuff.
Well, new research presented at the Endocrine Society’s 92nd Annual Meeting in San Diego explains why this may be the case. And it has everything to do with the activation of ghrelin, the “hunger hormone.”
Before we get to the newest study, let’s learn a little more about this “hunger hormone.”
Ghrelin is a hormone located in the stomach that sends hunger signals to the brain. When ghrelin levels are too high, the brain wants food – even if we are full.
And when ghrelin levels are high, the food we crave is high in calories – especially foods that are loaded with fat.
Here is where it gets interesting: ghrelin helps you feel good. In fact it helps you feel REALLY GOOD by activating some of the same regions of brain that are also activated by cocaine! So let’s just say it is highly motivational.
Ghrelin and high calorie cravings
In a study on micei, Dr. Jeffrey Zigman and his team found that mice injected with ghrelin chose to be in a room previously anchored with a high calorie treat versus a room anchored with a low calorie treat. The mice not injected with ghrelin had no preference for either room.
For clarity, the mice with elevated levels of ghrelin just “felt better,” in the high calorie room, “The mice’s behavior had nothing to do with eating,” Zigman said. “Their behavior was linked to obtaining the more pleasurable thing.”
In a second test, Zigman tested how long mice would continue to poke their noses into a hole in order to receive a pellet of high-fat food. The non-ghrelin group gave up far faster than the mice injected with ghrelin.
A new way to increase ghrelin levels and your cravings for fatty foods…
Skip breakfast. In the studyii referred to earlier in this article, researchers recruited healthy (not obese) adults to test this theory.
Here were the conditions:
- Subjects came into the lab on three separate mornings.
- Each time, subjects would be asked to view pictures of either high calorie foods (chocolate, cake and pizza) or low calorie foods (salads, vegetables and fish).
- Then, using a keypad, the subjects rated how appealing they found each food picture.
- There were, however, three different conditions:
- Condition one: subjects came into the lab 90 minutes after eating breakfast and were injected with a saltwater solution 40 minutes before viewing the pictures.
- Condition two: subjects came to the lab 90 minutes after eating breakfast and were injected with ghrelin 40 minutes before viewing the pictures.
- Condition three: subjects came to the lab after skipping breakfast and were injected with the saltwater solution 40 minutes before viewing the pictures.
When injected, neither the researchers nor the subjects were aware of whether they were injected with salt water or ghrelin.
The results: Skipping breakfast is just like injecting ghrelin
The group that skipped breakfast (c) AND the group that ate breakfast and had the ghrelin injection (b) both preferred the high calorie foods.
The group that ate breakfast AND had the salt water injection (a) preferred the low calorie foods.
So don’t skip breakfast if weight loss is your goal!!
The best breakfast for reducing ghrelin (and your cravings)…
In a study, iiipublished in The American Journal of Clinical Nutrition, researchers determined that protein is the best way to lower post meal ghrelin levels.
The ingestion of fats had little to no effect on post meal ghrelin levels, meaning that eating fat for breakfast is not going to help you make better decisions later in the day.
The ingestion of carbohydrates had an initial ghrelin lowering effect. But in a short period of time after eating carbohydrates, the ghrelin levels not only rebounded, but after only two hours, they rose to an even higher level than before. So eating lots of carbohydrates might also be counterproductive.
So, if you want to control your cravings for high calorie, fatty foods throughout the day, it might be wise to include a lot of protein along with a limited amount of carbohydrates and fats. I am not sure of the types of carbohydrates and fats used in the study, so it might be that carbohydrates high in fiber have a different effect – I just don’t know.
And you definitely require a certain amount of good fat in your diet, so please don’t overdo this.
A ghrelin pill?
Don’t expect ghrelin to show up in your local health food hotspot any time soon. Other studies indicate that artificially reducing ghrelin is also associated with a rise in feelings of depression.
Would losing weight be worth risking depression? Sadly, when people were surveyed on this question back in 2008, the majority of people said it would be worth the risk.
So would you take a pill that would help you lose weight even if you knew it would probably make you feel bad?
Please leave me your thoughts…
iPerello, Mario, and Ichiro Sakata, Shari Birnbaum, Jen-Chieh Chuang, Sherri Osborne-Lawrence, Sherry A. Rovinsky, Jakub Woloszyn, Masashi Yanagisawa, Michael Lutter, Jeffrey M. Zigman. “Ghrelin Increases the Rewarding Value of High-Fat Diet in an Orexin-Dependent Manner.” Journal of Biological Psychiatry. May 1 2010. Vol. 67, Issue 9, 880-886.
iiThe Endocrine Society 92nd Annual Meeting. San Francisco, California. June 21, 2010.
iiiWendy AM Blom, Anne Lluch, Annette Stafleu, Sophie Vinoy, Jens J Holst, Gertjan Schaafsma and Henk FJ Hendriks. “Effect of a High-Protein Breakfast on the Postprandial Ghrelin Response.” American Journal of Clinical Nutrition. February 2006. Vol. 83, No. 2, 211-220.