Let's say you went on a strict diet for 2 weeks in the hopes of losing fat.
That is precisely what researchers did to a group of overweight men and woman who stayed in a medical centre for two weeks.
One group of individuals were given just 5 and 5 1/2 hours time in bed, while the other group were offered 8 1/2 hours in bed.
Although weight loss occurred under both conditions, the type of weight loss came from very different sources.
The 5 hours group lost 70% of their weight from lean body mass--muscle mostly.
However the group that slept 8 or more hours lost well over 50% of fat while preserving muscle.
When you don't get enough sleep, the body seems to become especially stingy about giving up fat. Instead muscle mass is depleted while fat is retained.
Lean and toned is unlikely to be the outcome of dieting when you are cutting sleep short.
Short sleep will increase hunger and appetite, compromise impulse control within the brain, increase food consumption, decrease feeling of food satisfaction after eating, and prevent effective weight loss when dieting.