Putting in hours at the gym may mean nothing if you’re not also putting in hours in your bed. Though many people try to achieve weight loss while skimping on their ZZZs, a recent study suggests that a good night’s sleep may be the key ingredient missing from their diet.
The study monitored 10 participants over a two-week period and split them into two groups. Both parties were fed the same quantity of calories and allowed the same type and amount of physical activity, but were required to sleep for different lengths of time. The findings revealed that participants who slept 8.5 hours a night experienced more body fat loss than those who slept 5.5 hours a night.
Both groups averaged the same 6.5 pound weight loss, but those who slept less lost more lean body mass than body fat. Lean Body Mass is what makes up our muscle tissue, bones and organs. In addition to its essential role in facilitating basic human functioning, it is more metabolically active than fat tissue. In other words, lean body mass is not the type of weight anyone wants to lose and could even be harmful to your health.
The results of this study are likely attributed to metabolic disturbances which occur with inadequate sleep. These cause the body to burn calories from stored protein and carbohydrates rather than calories from fat. Additionally, research has shown an association between sleep duration and the secretion of appetite-regulating hormones like leptin (lower with less sleep) and ghrelin (higher with less sleep). While leptin promotes feelings of satiety and suppresses appetite, ghrelin promotes hunger and fat retention. Additionally, people tend to eat more mindlessly and make undesirable food choices when they are tired, and night owls have a propensity to engage in late night snacking, often exceeding their caloric needs.
While no definitive conclusions can be drawn from this study given its small subject pool and mere two week timeframe, it does support the vast body of evidence suggesting that sleep is an imperative component to achieving optimal health. So if you’ve plateaued with your weight loss despite making the best food choices possible and exercising most days of the week, it may be time to consider your sleeping habits, and try hitting the sack an hour or two earlier.