The average length of a night of sleep for an adult in the United States has decreased by 2 hours in the last 50 years. Increasing evidence reports the damaging effects of sleep deprivation and restriction on hormone release, cardiovascular function, and glucose regulation. Now, in fact, evidence shows that sleep loss undermines dietary efforts to lose weight, especially body fat.

Just the latest in a series of studies evaluating the effects of sleep on weight gain and obesity, a study from the University of Chicago, published in the Annals of Internal Medicine, found that insufficient sleep reduces the effectiveness of normal dietary interventions for weight loss. The study included 10 overweight adults who completed a 2-period 2-condition crossover study. The participants experienced 14 days of moderate caloric restriction and either 8.5 or 5.5 hours of nighttime sleep opportunity. The goal of the study was to measure loss of body fat and loss of fat-free body mass under each sleep condition. Hormone concentrations, energy expenditure, and hunger were also included in the analysis.

Overall, a short night’s sleep significantly decreased the amount of body fat lost by 55% (3 lbs vs. 1.3 lbs with 8.5 hours vs. 5.5 hours sleep, respectively). Also, the loss of fat-free body mass significantly increased by 60% with 5.5 hours sleep compared to 8.5 hours (5.3 lbs vs. 3.3 lbs). Further, participants with 5.5 hours sleep experienced increased hunger compared to the group with more sleep.

Other studies have demonstrated similar benefits of sleep, and correlated sleep restriction to the rise in obesity. Under conditions of sleep restriction (either shortened sleep or complete deprivation), subjects experienced reduced levels of leptin (the hormone that decreased appetite), increased levels of ghrelin (the hormone that simulates appetite), and increased hunger and appetite, particularly for calorie-dense, carbohydrate-rich foods. One study also concluded that sleep-restricted individuals consumed more calories from snacks than meals.

In addition to promoting weight gain and decreasing fat loss, chronic sleep loss induces excess glucocorticoid levels, which promotes memory loss and accelerates the aging process. Further, sleep loss contributes to the dysregulation of carbohydrate metabolism, specifically glucose, increasing the risk for the metabolic syndrome and type 2 diabetes.

Decreasing sleep to the minimum tolerable levels appears efficient and almost advantageous in today’s society. But, the long term effects of limiting the body’s ability to rest has significant metabolic and endocrine consequences, which may result in weight gain and obesity. Promoting healthy sleep schedules and habits for adults and children is a simple intervention that could result in large public health gains.

References

Copinschi G (2005). Metabolic and endocrine effects of sleep deprivation. Essential psychopharmacology, 6 (6), 341-7 PMID: 16459757

Leproult R, & Van Cauter E (2010). Role of sleep and sleep loss in hormonal release and metabolism. Endocrine development, 17, 11-21 PMID: 19955752

Nedeltcheva AV, Kilkus JM, Imperial J, Kasza K, Schoeller DA, & Penev PD (2009). Sleep curtailment is accompanied by increased intake of calories from snacks. The American journal of clinical nutrition, 89 (1), 126-33 PMID: 19056602

Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, & Penev PD (2010). Insufficient sleep undermines dietary efforts to reduce adiposity. Annals of internal medicine, 153 (7), 435-41 PMID: 20921542

Schmid SM, Hallschmid M, Jauch-Chara K, Born J, & Schultes B (2008). A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal-weight healthy men. Journal of sleep research, 17 (3), 331-4 PMID: 18564298

Spiegel K, Tasali E, Penev P, & Van Cauter E (2004). Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of internal medicine, 141 (11), 846-50 PMID: 15583226

Van Cauter E, Spiegel K, Tasali E, & Leproult R (2008). Metabolic consequences of sleep and sleep loss. Sleep medicine, 9 Suppl 1 PMID: 18929315