In recent years, diet trends such as intermittent fasting have popularized the practice of delayed or restricted eating for many people looking to manage caloric intake. Still, many open to restructuring their schedules have the same question: When is the right time to avoid eating?
The answer is at night, according to a new study out from Vanderbilt University.
For the study, Johnson and postgraduate student Kevin Kelly tested meal time restriction by monitoring the metabolism of middle-aged and older adults in a whole-room respiratory chamber, under controlled conditions, over two separate 56-hour sessions—both with the same overnight fasting period.
They found that, while the two sessions did not differ in the amount of food eaten or the amount of physical activity of the participants, the daily timing of nutrient availability coupled with the body’s increased metabolism during sleep (thanks to the body’s circadian rhythms) flipped a switch on fat burning: In each instance, late-evening snacking delayed the body’s ability to target fat stores for energy and instead caused the body to target the readily accessible carbohydrates newly introduced into the body.
The study has important implications for eating habits, providing evidence contrary to a recent trend of skipping breakfast and suggesting instead a daily fast from supper to breakfast to help optimize weight management.