Various researchers have found, over the past few years, that getting less than about 7 hours of sleep per night is correlated with weight gain and they have even discovered
the probable mechanisms for such weight gain. An estimated 63% of American adults do not get the recommended eight hours of sleep a night, according to the National Sleep Foundation. The average adult gets 6.9 hours of sleep on weeknights and 7.5 hours on weekends, for a daily average of seven hours.
Eve Van Cauter (see link below) is one of the top researchers in this area. She has discovered that less than optimal amounts of sleep, even in one night, can lead to changes in two hormone levels within people: Ghrelin
(which influences feelings of hunger) and Leptin
(which tells the person that it is time to stop eating). When one is sleep deprived, ghrelin levels increase while leptin decreases, which results in people eating more and not knowing as well as they could when they are full. Not a good thing.
In addition to studies on these two hormones and their relationship with sleep, others show a correlation between less sleep and weight gain. One study, including 70,000 subjects, found that women who slept 5 hours per night were 32% more likely to experience major weight gain (an increase of 33 pounds or more) and 15% more likely to become obese over the course of the 16-year study, compared to those who slept 7 hours a night. Those women who slept 6 hours per night were still 12% more likely to experience major weight gain, and 6% more likely to become obese, compared to women who slept 7 hours a night. In another study of 1,024 people aged 30-60, Body Mass Index (BMI) levels were recorded. Those who slept only three hours a night had a 5% increase in body weight over 15 years.
Inadequate sleep can:
· interfere with the body's ability to metabolize carbohydrates and causes high blood levels of glucose, which leads to higher insulin levels and greater body-fat storage
· reduce levels of growth hormone--a protein that helps regulate the body's proportions of fat and muscle
· lead to insulin resistance and contribute to increased risk of diabetes
· increase blood pressure
· increase the risk of heart disease
GET ENOUGH SLEEP!
Patel SR, Malhotra A, White DP, Gottlieb DJ, Hu FB. Association between reduced sleep and weight gain in women. Am J Epidemiol. 2006 Nov 15;164(10):947-54.
Spiegel K, Leproult R, Tasali E, Penev P, and Van Cauter E. (2004). Sleep curtailment results in decreased leptin levels, elevated ghrelin levels and increased hunger and appetite. Annals Int Med 141(11):846-50.
Spiegel K, Leproult R, L'Hermite-Balériaux M, Copinschi G, Penev P and Van Cauter E. (2004). Impact of sleep duration on the 24-hour leptin profile: relationships with sympatho-vagal balance, cortisol and TSH. J Clin Endocrinol Metab 89(11):5762-71.
Van Cauter E, Latta F, Nedeltcheva A, Spiegel K, Leproult R., Vandenbril C, Weiss R, Mockel J, Legros JJ, Copinschi G. (2004). Reciprocal interactions between GH axis and sleep. Growth Horm IGF Res. 14 Suppl A:S10-7.