Ever wonder why you feel sleepy after large meals? This actually has its origin in evolution. During ancient times, our ancestors would not sleep until after they were able to acquire food. Sleep was a reward for them after they had done their day's chores such as securing food.
Sleep and weight are found to have some connection. For instance, the condition sleep apnea suffered by obese people make it difficult for them to sleep comfortably.
There are studies which linked sleep with gaining weight. A study conducted by Case Western Reserve University with more than 68,000 women revealed that those who sleep for less than 5hours a night gained weight compared to those who sleep 7 hours a night.
Women who sleep less have greater chances of becoming obese compared to women who sleep a full night. Also, women who sleep less also consumed lesser calories.
This occurrence could be explained by the hormones in our bodies. Our body release leptin to the bloodstream which determines if you have enough fat in store. It functions as the appetite suppressor. The ghrelin is another hormone released by the stomach to tell us that we are hungry.
When we don't sleep our leptin levels decreases and the ghrelin levels increase. This means that your body cannot determine if you have enough fat stored because the leptin is inhibited and the body always craves for food because more ghrelin hormones are released.
Short sleep, usually 4 hours or less every night, can cause lower leptin and higher ghrelin. One should see to it then that he has more than 4 hours of sleep every night to avoid this dilemma.
Also, orexin system which is found in the brain region called hypothalamus affects leptin release which in turn could influence sleep and appetite. Latest studies enable the scientists to establish the connection between sleeping and appetite. In the tests conducted on mice, a gene which is controlled by circadian clock is found to control sleeping and walking. It is the same gene that results in fat deposits. When the scientists turn off the clock gene, the mice didn't gain weight even when feed with high calorie foods as compared to another group of mice whose clock weren't turned off. This means that if the gene for sleeping is controlled, weight also follows.
