The effects of sleep deprivation are slowly gaining attention amongst fitness and wellness professionals. Getting adequate sleep quantity and quality is not only essential to optimizing mental and physical recuperation, it may be essential to preventing obesity.In a recent study published in the journal Sleep, researchers from Wake Forest University reported that getting less than 5 hours of sleep or more than 8 hours leads to increased intra-abdominal fat when compared to those who sleep for 6 or 7 hours.
More than 1,000 African- and Hispanic-Americans were interviewed to obtain information on sleep habits, nutrition, physical activity and lifestyle. They also participated in a CT scan, which was used to assess both visceral and subcutaneous abdominal fat. Baseline measurements were then compared to a re-assessment at 5 years.
Participants who slept less than 5 hours a night experienced a 32% increase in deep abdominal fat over 5 years, while those with averaged more than 8 hours of sleep increased by 22%. Subcutaneous abdominal fat increased similarly.
After factoring in lifestyle factors such as total calorie intake, education levels, physical activity and smoking, sleep duration persisted as an independent risk factor for increased abdominal adiposity, especially in participants under 40.
Researchers offer broad speculation to explain the cause and effect relationship of sleep to fat gain. The primary explanations involved increased daytime fatigue, which limits energy to participate in physical activity. In addition, some believe in the potential for sleep deprivation to inhibit appetite-suppressing hormones, thus leading to overeating.
Although this study replicates previous finding on sleep and abdominal fat, it is the first to assess this factor in minority populations.
Hairston, K.G., et al (2010) Sleep Duration and Five-Year Abdominal Fat Accumulation in a Minority Cohort: The IRAS Family Study. Sleep. 33(03): 289-295.
Amy Norton. (2010) Sleep habits linked to fat gain in younger adults. Reuters Health. March 1st.