A controlled study stated that sleep deprivation among young adults could be a reason for abdominal obesity and harmful visceral fat. 

The study included 12 healthy, non-obese people allocated randomly to controlled sleep restriction —4 hours of sleep a night for 2 weeks — or controlled sleep of 9 hours a night, followed by a 3-day recovery period. It was seen that by the end of 2 weeks, these participants gained 0.5 kg of extra weight which was significant but still very modest.

The patients with insufficient sleep ate on average 308 calories extra per day more than their controlled sleep counterparts (95% confidence interval, 59.2 - 556.8 kcal/day; P = .015), and had a weight gain of 0.5-kg (95% CI, 0.1 - 0.8 kg; P = .008). It was also tied to an increase of 7.8-cm² in visceral adipose tissue (VAT) (95% CI, 0.3 - 15.3 cm²; P = .042), corresponding to an increase of around 11%.

Even after the recovery period, VAT kept rising in the sleep-deprived patients though the body weight and subcutaneous fat decreased, and the increase in total abdominal fat flattened. 

Further research and study were necessary to understand the mechanism of VAT accumulation with less sleep. (Medscape Medical News, March 28, 2022)