The time of the day when food is consumed may determine how many calories in it will be burned by the body, according to a study which suggests that a daily fast between the evening meal and breakfast can optimise weight management.
The researchers, including Kevin Kelly from Vanderbilt University in the US, said the balance between weight loss and gain is predominantly determined by diet, the quantity of food consumed, and the amount of exercise a person gets.
They said the time of the day when most food is eaten also determines how well a person burns dietary calories. According to the study, published in the journal PLOS Biology, the human body’s daily biological clock and sleep regulate how the food is metabolised.
It added that the choice of burning fats or carbohydrates also changes depending on the time of day or night. The scientists said the circadian rhythm, or the body clock, is programmed to assist the body burn fat when people sleep.
As a result, they said, when people skip breakfast and then snack at night, it may lead to a delay in burning the fat.
In the study, the researchers monitored the metabolism of mid-aged and older subjects in a whole-room respiratory chamber over two separate 56-hour sessions. In each session, they said, lunch and dinner were presented at the same times but the timing of the third meal differed between the two halves of the study.
In one of the 56-hour sessions, the additional daily meal was presented as breakfast whereas in the other session, a nutritionally equivalent meal was presented to the same subjects as a late-evening snack, the scientists said. However, they said the duration of the overnight fast was the same for both sessions.
While the two sessions did not differ in the amount or type of food eaten, or in the subjects’ activity levels, the daily timing of nutrient availability, coupled with sleep control of metabolism, flipped a switch in the subjects’ fat/carbohydrate preference, the study noted.
The late-evening snack session resulted in less fat burned when compared to the breakfast session, it said. Based on these observations, the scientists said the timing of meals during the day/night cycle may affect the extent to which ingested food is used versus stored.
According to the researchers, this study has important implications for eating habits, suggesting that a daily fast between the evening meal and breakfast may optimise weight management. (PTI)
