When we think about weight loss, we typically start thinking about changing two things; improving our diet and embarking on an exercise program. But ask yourself; is getting a good night’s sleep as high on your priority list as your diet and exercise?
Numerous studies have identified a correlation between sleep and body weight. One such study was done at Case Western Reserve University. In this study, 68,183 ladies were followed for 16 years. It was concluded at the end of the study that women who slept less than five hours were 30% more likely to gain 30 pounds over those 16 years than those ladies that averaged over 7 hours of sleep. (Patel et al. 2006)
Another study out of the Stanford University School of Medicine revealed similar findings. During the study, the researchers examined the sleep patterns of 1,024 volunteers between the ages of 30 and 60. Study volunteers underwent nocturnal polysomnography (a test during which a number of physiologic variables are measured and recorded during sleep) and blood sampling once every four years. They also reported on their sleep habits every five years through questionnaires and six-day sleep diaries. The findings revealed that people who slept less than 5 hours compared with those who slept 8 hours per night have 3% higher Body Mass Index (BMI).(Taheri et al. 2004)
So, what is the connection?
There are two major hormones that contribute to how successful we are in our nutritional efforts to be a healthy weight; leptin and ghrelin. Leptin is a hormone produced in the fat cells and is responsible for sending a signal to the brain that you are full after you have eaten enough. Ghrelin is produced in the gastrointestinal tract and sends a signal to the brain to let you know that you are hungry when it is time to eat. When quality sleep is compromised in the body, leptin levels are decreased which interrupts your body’s ability to determine that you are full; this will typically lead to overeating. In addition, ghrelin is produced in higher amounts which means your body is sending a signal to the brain that it is time to eat even when it is not; this too can likely to lead to overeating.