On a weight loss diet, we steer clear of fatty and sugar-laden foods. With some determination, we manage to do so but it gets difficult on certain days, mostly all those days after a sleepless night. Lack of sleep can bend our food preferences towards more sweet and high-fat foods like cheesy pizza or cakes and ice-creams. It actually does happen with most of us but till date, nobody knew the exact reason behind it and the exact mechanism that plays the role. A new Northwestern University's medicine study, published in journal ‘eLife' investigated this further assuming that the sense of smell tells the human brain what to eat. A sleepy nose affects the olfactory system to make the food odours stronger for the brain. Sleep deprivation could have an impact on the endocannabinoid system, a complex network of molecules in the nervous system that controls biological processes such as appetite.
The team of researchers studied the effect of a four-hour night's sleep on 25 healthy people. Their blood samples were taken the next day and it showed increased amounts of 2-oleoylglycerol, a molecule that is part of the endocannabinoid system.
(Also Read: 7 Foods That May Leave You Sleep Deprived)
Lack of sleep can bend our food preferences towards more sweet and high-fat foods
Surabhi Bhutani, lead author of the study said “Here we test the hypothesis that neural processing in central olfactory circuits, in tandem with the endocannabinoid system (ECS), plays a key role in mediating this relationship. We combined a partial sleep-deprivation protocol, pattern-based olfactory neuroimaging, and ad libitum food intake to test how central olfactory mechanisms alter food intake after sleep deprivation.”
The sleep-deprived participants were provided the choice to eat whatever they wanted. It was seen that people with higher levels of 2-oleoylglycerol reached out to more energy-dense foods. The team realised that in these people who did not get enough sleep the night before, an odour-processing region called the piriform cortex was encoding smells more strongly.
“We found that sleep restriction increased levels of the ECS compound 2-oleoylglycerol (2-OG), enhanced encoding of food odors in piriform cortex, and shifted food choices toward energy-dense food items,” Surabhi Bhutani concluded.
These findings pave way for a potential neurobiological pathway that may guide changes in ECS to regulate food choices, especially to avoid weight gain.