Cause ; Lack of sleep

Sleep and weight gain are closely related, and weight gain is one of the common effects of lack of sleep. Obesity and sleep apnea occur together frequently, as do lack of sleep, depression and weight gain. Mounting evidence suggests that lack of sleep has multiple effects that can all result in excess weight.

Sleep and Weight Gain

Several studies have noted the connection between sleep and weight gain. A study published in the journal "Sleep" (2010) examined sleep and weight gain in over 35,000 employees of a Japanese electric power company. Most employees were male. The study found that men who slept five or less hours a night were twice as likely to experience weight gain as those who slept seven to eight hours a night.

Too much sleep also affected weight: Men sleeping more than nine hours a night were 1.4 times more likely to gain weight over the course of the study when compared to men who slept seven to eight hours.

Other studies suggest the relationship between lack of sleep and weight gain also affects women. According to a 2006 study from the Case Western Reserve University in Cleveland, women who slept less than five hours a night were 32 percent more likely to gain 33 pounds or more over the 16-year study period than women who slept at least seven hours a night.

Effects of Lack of Sleep on Appetite

Lack of sleep lowers levels of leptin, a protein that regulates and controls appetite. Low leptin levels may increase appetite, leading to weight gain.

Appetite may also be affected by the mind's reaction to both sleepiness and hunger. The two conditions cause similar psychological sensations. People used to living with a lack of sleep sometimes assume low energy levels are a sign of hunger when they are actually sleepy.

The Sleep Apnea/Obesity Connection

Obesity is linked to sleep apnea. Obesity can contribute to sleep apnea, but new research suggests the sleep disorder also encourages weight gain. Sleep apnea causes frequent short pauses in breathing that disrupt sleep.

A study presented at the 2009 Annual Meeting of the Associated Professional Sleep Societies noted that as sleep apnea severity rises, so too does the risk of obesity. Obesity and sleep apnea aggravate each other. Obesity causes sleep apnea, which in turn leads to more weight gain.

Other Sleep and Weight Factors

The effects of lack of sleep on weight gain are far-reaching. In addition to physical effects of lack of sleep, people experiencing sleep deprivation find it difficult to gather the energy needed for exercising, or even preparing healthy meals. People struggling to lose weight should consider examining their sleep habits and consider the possible connections between obesity and sleep.