Why Sleep is Important Especially When Dieting


By Staff Reports

(DGIwire) – There is an established connection between sleeping and hunger. This is because there is a connection between sleep and the levels of leptin and ghrelin in the body.

Ghrelin is a hormone that is released when we are hungry. It increases our appetite. Leptin has the opposite effect and is released to signal that we’re full which decreases appetite and increases our sense of fullness.

In one small study that was done on 12 men, 2 days of sleep deprivation followed were followed by 2 days of as much sleep as the participants wanted. Their hormone levels, appetite, and activity levels were monitored. On days of sleep deprivation, leptin levels went down and ghrelin levels went up.

This resulted in their appetite increasing with a 45% increased desire for higher calorie foods. 

In another study, people on a low-calorie diet lost the same amount of weight whether they slept an average of 8.5 hours or 5.5 hours each night. They all lost an average of nearly 7 pounds. However, those who slept 8.5 hours lost much more fat, while those on 5.5 hours lost mainly muscle, not fat. The researchers concluded that adequate sleep is a key contributor to managing body composition.

The researchers found that while getting 8.5 hours sleep each night that over 50% of the participants’ weight loss consisted of fat. When sleep time was reduced to 5.5 hours sleep each night only 25% of the participants’ weight loss consisted of fat. Although they lost the same amount of weight, the composition of the loss was different.

“Most diets result in a certain amount of lean tissue (LBM) loss, some more than others. All dieters should try to lose as little LBM as possible. This can be overcome by including a small amount of proper strength training. Not getting enough sleep when restricting calories will undermine any attempts a dieter makes to limit loss of LBM. Fat, not weight is what people really want to lose. Those starting a weight-loss program need to make sure they are going to get enough sleep each night,” according to Tom Griesel, co-author of TurboCharged: Accelerate Your Fat Burning Metabolism, Get Lean Fast and Leave Diet and Exercise Rules in the Dust

The researchers concluded the amount of human sleep contributes to the maintenance of fat-free body mass at times of decreased energy intake. Lack of sufficient sleep may compromise the efficacy of typical dietary interventions for weight loss and related metabolic risk reduction. They also noted feelings of increased hunger with less sleep.

Griesel adds, “Sleep is intricately related to our energy balance and metabolic survival. Lack of sleep, especially when restricting calories, creates stress and has a catabolic effect triggering built-in survival mechanisms resulting in loss of LBM and hoarding fat stores. Loss of excess body fat is good but loss of LBM is always bad. It takes the right combination of variables to be most successful.”

If you’re not sleeping enough yet doing everything else 100% right, the best possible scenario is that you will have to diet for longer, while being even hungrier all the time.  There is strong evidence that sleep is essential for optimal body composition and lack of sleep makes it harder to burn fat and increases your risk of LBM.

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