There's a scientific reason you crave junk food when you don't get enough sleep - CNN

What is it about sleep exhaustion and junk food? The answer lies in history, back when we dug in the dirt for starchy tubers, foraged for sweet berries and gorged on fatty fish. Simply put, a lack of sleep triggers ancient instincts that yearn for rich, sweet, fatty foods.....

https://www.cnn.com/2019/10/23/health/sleep-junk-food-cravings-wellness/index.html