When it comes to losing weight, sleep is often a neglected factor, but it also plays a big role. The IFResearch has shown that sleeping less than recommended is associated with an increased risk of obesity. Plus, it can influence how easily you lose weight.
What the investigations found
One study found that people who ate a calorie-restricted diet for two weeks and slept 5.5 hours a night lost less weight than those on an 8.5-hour sleep schedule. In addition, they experienced a greater loss of muscle mass.
Another study found similar results over an eight-week period, when sleep dropped from just one hour a night to five nights a week. Furthermore, the data shows that trying to “catch up” on lost sleep over the weekend is not enough to reverse the negative effects of insufficient sleep in people on a calorie-restricted diet. The recommended sleep duration for adults is 7-9 hours per night.
Metabolism, appetite and sleep
There are several reasons why shorter sleep may be associated with higher body weight and may affect weight loss.
These include changes in metabolism, appetite, and food selection. Sleep affects two important hormones: leptin and ghrelin.
Leptin is a hormone that reduces appetite, so when leptin levels are high, we generally feel full. On the other hand, ghrelin is a hormone that can stimulate appetite and is often referred to as the “hunger hormone” because it is believed to be responsible for feeling hungry.
Several studies have found that short sleep has been associated with higher levels of ghrelin and lower levels of leptin. This combination could increase your appetite, making calorie restriction more difficult to adhere to. This means that, in the long term, lack of sleep can lead to weight gain due to these changes.
Lack of sleep affects the way we see food
Insufficient sleep leaves its mark on the way we select our food and the way our brain perceives food. The researchers found that the brain areas responsible for reward were more active in response to food in people who did not get enough rest compared to those who did not get enough sleep (9 hours of sleep per night).
This may explain why people who don’t get enough rest tend to snack more and choose foods that are high in carbohydrates or sweets.
Sleep deprivation also affects insulin response
Sleep duration also influences metabolism, especially glucose (sugar) metabolism. When we eat, the body releases insulin, a hormone that helps process glucose in the blood. But inadequate sleep can affect the body’s response to insulin, reducing its ability to absorb glucose.
We may be able to recover from an occasional missed night, but in the long run, lack of rest could lead to obesity and type 2 diabetes. According to scientists, a single night of just four hours of sleep is enough to affect insulin response to glucose intake in healthy young men. Excess glucose is converted to fatty acids and stored as fat. And over time, you gain weight.
Can sports help us?
Physical activity could be a countermeasure against the damaging impact of sleep deprivation, which is promising.
Exercise reduces the level of ghrelin (appetite) and increases the level of peptide YY, a hormone that is released in the intestine and is associated with satiety. After exercise, people tend to eat less, especially considering the energy consumed.
Research has also shown that exercise can protect against metabolic deficiencies that result from sleep deprivation by improving the body’s response to insulin.
All of this sounds promising, but more studies are needed to determine the role of long-term physical activity in people with little sleep.