Are you eating right, exercising, and still not losing fat? It may not be the way you’re eating that’s the problem – but the way you’re sleeping. According to a new study, too little sleep can thwart even the best laid diet and exercise plans.
Lack of Sleep and Fat Loss
In a study published in the Annals of Internal Medicine, researchers compared the amount of fat loss in two groups of overweight or obese people. Both ate similar diets and had the same level of activity, but they slept differing amounts. One group got 8.5 hours of sleep each night for fourteen days, while the other spent only 5.5 hours sleeping.
How did sleep affect their fat loss efforts? Interestingly, both groups lost the same amount of weight, but the group who got too little sleep (5.5 hours) lost less body fat but more muscle tissue than the well-rested group. Since losing fat, not lean body mass, Is the goal for most people, a lack of sleep had some undesirable consequences.
Why Does Too Little Sleep Prevent Fat Loss?
Researchers speculate that two critical appetite hormones, leptin and ghrelin, make losing fat more difficult for people who get too little sleep. Leptin is a hormone produced by fat cells that signals satiety, while ghrelin, produced by cells in the lining of the stomach, sends a hunger signal to the brain. When these hormones get out of whack, due to sleep deprivation, it stimulates appetite – and causes overeating. The result? The sleep-deprived person snacks more.
Another reason people who get too little sleep have trouble losing fat relates to the effects of a hormone called cortisol. Sleep deprivation causes cortisol levels to rise. This increases insulin resistance and promotes the breakdown of muscle tissue. People with high cortisol levels also have a more voracious appetite, especially for carb-rich foods. Cortisol commits another weight loss sin. It encourages the body to store fat in a place most people don’t want it – the tummy.
Is Too Little Sleep a Barrier to Losing Fat: The Bottom Line?
This is a small study, so it’s difficult to draw firm conclusions, but previous research also shows that getting enough sleep is important for successful fat loss – and for overall health. If you’re trying to lose fat, and you’re sleeping less than seven hours a night, it could be harder to reach your goals. Eat a healthy diet and exercise, but make sleep a priority too.
Eurekalert.org. “Sleep loss limits fat loss”