A CNN review article describes that people are craving junk food with a lack of sleep. This research has been conducted at the University of Chicago. The main investigator was behavioral neuroscientist Erin Hanlon, who studied the connection between brain systems and behavior. He says that there are at least three hormones that play a role in people craving junk foods in the middle of the night.
- There is the hormone lectin that suppresses appetite. People feel they had enough to eat and they start losing weight. A lack of sleep reduces the body’s lectin production.
- The lining of the stomach produces ghrelin. The body absorbs ghrelin in the small intestine and increases hunger feelings in the brain. With sleep deprivation ghrelin levels spike. The end result is an increase in hunger and craving for junk foods.
- Researchers detected the first cannabinoid receptor in 1988. Now we know there are at least 2 different cannabinoid receptors, CB1 and CB2. Dr. Erin Hanlon has proven in a publication that cannabinoids cause food cravings.
- 14 participants slept 4.5 hours for 4 consecutive nights in comparison to controls who slept 8 hours for 4 consecutive nights. The researchers measured their cannabinoid blood levels, particularly the endocannabinoid 2-arachidonoylglycerol (2AG). Sleep deprived participants reported higher food cravings for fatty, starchy and sugary foods. Their afternoon levels of 2AG showed elevation in comparison to the individuals who slept well.
Ancient food habits
Way back in history of mankind when high carbs and fats were rare the three hormones mentioned above were in balance most of the time. But in today’s society junk foods with too much sugar, salt, fat and starchy foods are freely available. Our internal hormone system did not have time to adjust to modern life, it still reacts with the way it always reacted. As a result, when we are sleep deprived, we get hungry due to high ghrelin, low leptin and high 2-arachidonoylglycerol.
“Evolutionarily speaking, it was a big deal to have a high carb, high fat meal, because you didn’t necessarily have those all of the time,” explained Hanlon. “It’s only in the recent time of human existence that we have been able to have food around the clock or food that is high in saturated fats and high in carbs,” Hanlon continued. “And our brain has not evolved as quickly as the food choices that have become available.”
Sleep deprivation seems to trigger cannabinoid receptors in the brain to make us eat junk foods. At the same time low leptin and high ghrelin levels reinforce these food cravings. This results in weight gain, as high sugar and saturated fat snacks contain a lot of calories. On top of that too much salt contained in junk foods is also feeding into more cravings and consumption of soft drinks and beer. We need to rethink our food habits, make sure we sleep long enough to avoid faulty hormone signals and balance our meals in the sense of a Mediterranean type diet. This will rebalance the three hormones discussed and help us to overcome any abnormal food cravings. Another important fact is to remember to sleep 7 to 8 hours every night. This will restore our energy and prevent food cravings.