Lack Of Sleep Limits Your Fat Loss
By: Jayson Hunter RD, CSCS
When you cut back on sleep research is starting to show that it can affect your weight loss. Some studies are also showing that you lose less fat stores then if you got a good nights sleep.
In this study when weight loss participants got a full nights sleep they lost the same amount of weight as when they didn't get a full nights sleep. The big difference though is that when they got a good nights sleep more than half the weight they lost was fat.
When their sleep was cut back then only 25% of their weight loss came from fat loss. They also felt hungrier when lacking sleep.
What they believe happened here was that when their sleep was reduced their body produced greater levels of ghrelin, which is a hormone that triggers hunger and also slows down your metabolism or the rate at which you burn calories.
This was a small study conducted with only 10 overweight, but otherwise healthy individuals. They were each placed on individualized diets and were studied twice. One time was for 14 days in the lab with the participants getting 8.5 hours of sleep each night. The 2nd time was also for 14 days, but they only were able to get 5.5 hours of sleep per night. The calories during both tests were about 1450 calories per day.
The participants lost on average about 6.6 pounds during each 14 day session. So you would think that lack of sleep made no difference in weight loss. Though when they looked at the amount of fat lost compared to weight loss they discovered something significant. During the 14 days with 8.5 hours of sleep each night the lost 3.1 pounds of fat and 3.3 pounds of fat free body mass (lean muscle, protein).
During the 14 days of only 5.5 hours of sleep they only lost 1.3 pounds of fat and 5.3 pounds of fat fat free mass (lean muscle, protein).
Researchers also found that getting adequate sleep controlled the ghrelin levels, but when they slept for only 5.5 hours ghrelin levels rose and they were hungrier during those 2 weeks.
What this shows at least with a small population is that sleep may play a very important role in your overall weight loss and whether you lose fat mass or lean muscle.
Nedeltcheva AV, et al. Insufficient sleep undermines dietary efforts to reduce adiposity. Ann Intern Med. 2010; 153:435-441.
We are a GMP Rated facility, so what we say is in the bottle is really IN the bottle. Sure, it's extremely difficult to get certified, but we feel the extra effort is worth it. Don't you agree?