Food intake and appetite during sleep restriction Original paper

In this randomized crossover trial, sleep restriction increased hunger, cravings, fatigue, and energy intake from snacks.

The effect of sleep restriction on hunger, dietary intake, fatigue, and cardiometabolic risk factors.

24 adult participants (average age of 21; 13 women and 11 men) without overweight or obesity (BMI<25 ) or sleep problems and had a chronotype of “definitely not evening type”.

In this randomized crossover trial, the participants’ activity levels and food intakes were monitored during 3 nights of restricted sleep (5 hours per night) and control sleep (8 hours per night). The conditions were separated by a washout period of at least 3 weeks.

The participants slept at home, with a wakeup time of 6 a.m. and a bedtime of either 10 p.m. or 1 a.m. They were provided with a daily allowance with which to purchase foods on days 2 and 3, during which hunger, appetite, desire for sweets, desire for fatty foods, sleepiness, and fatigue were assessed hourly using a visual analog scale. The participants reported all food intake (which included taking photos of all foods eaten), and an accelerometer device was used to track activity levels and step counts.

On day 4, fasted blood samples were collected to compare biomarkers such as glucose, insulin, cortisol, and lipids, as well as levels of the endocannabinoid 2-arachidonoylglycerol (2-AG; used to assess eating behavior). The participants then completed a sweet taste preference test and were provided with an ad libitum breakfast.

Area under the curve or overall ratings of hunger, desire for fatty foods, sleepiness, and fatigue were higher on day 3 of sleep restriction, compared to the control sleep. Although total energy intake on day 3 did not differ significantly between the conditions, sleep restriction led to greater intakes of energy and carbohydrates from snacks. Total dietary intakes and snack intakes on day 2 were similar between conditions.

Sedentary time and sedentary-to-light activity time were higher in the sleep restriction condition; however, there was no difference between conditions after adjusting for the amount of time spent awake.

During the ad libitum breakfast, energy and carbohydrate intakes were higher in the sleep restriction condition (362 vs. 277 kcal; 54 vs. 42 grams of carbohydrate). Levels of 2-AG were lower in the sleep restriction condition compared to the control condition, but there were no other differences in biomarkers between conditions.