Snacking is the first bad habit to lose if you want to find the line. However. After a busy day, what could be better than a little brioche or a square of chocolate to comfort yourself. Are you having trouble breaking this habit? Do not panic ! According to American researchers, succumbing to a snack at the end of the day would have less impact on health and on the silhouette.
Slimming: calories burn faster in the late afternoon
At the origin of a study published in the scientific journal Current Biology, scientists from the US National Institute on Aging, Brigham and Women’s Hospital in Boston, USA, Harvard University in the USA, the Finnish Cultural Foundation and the US National Institutes of Health have established that “the number of calories people burn at rest varies by time of day”. In effect, “people burn 10% more calories in the late afternoon and in the early evening than in the early morning.”
The reason ? The circadian cycle impacts the regulation of metabolism. This is a integrated biological rhythmtaking the form of a cycle of approximately 24 hours, and governing certain physiological processes such as sleep and food.
Energy expenditure is lower when body temperature drops
To arrive at these results, the researchers followed seven people for 37 days in a laboratory where it was impossible to know the time of day. In effect, the candidates were deprived of a clock, a window, a telephone and the Internet. In addition, the participants had a wake-up and bedtime schedule that varied each day. Each day, the schedule was shifted four hours from the day before. “They were doing the equivalent of traveling around the world every week, in terms of jet lag. So their body’s internal clock couldn’t keep up, and so it oscillated to its own rhythm”, explains Jeanne Duffy, of the Brigham and Women’s Hospital. This allowed scientists to measure metabolic rate, i.e. the amount of calories burned, at different times of the day.
Results : at rest, energy expenditure is lower when body temperature drops. In general, this process takes place in the last part of sleep, around 4:30 a.m. for a typical night. Conversely, this is the highest about 12 hours later, at the end of the afternoon for a classic cycle. “We were surprised to see that doing the same thing at one time of the day burned so many more calories than doing the same thing at another time of the day”, recognizes Kirsi-Marja Zitting, main author of the document.
Weight gain: avoid high-calorie foods in the evening or early in the morning
Asked by the Time, researcher Jeanne Duffy advises avoid high-calorie foods during slow-burn periodsin other words, in the evening or early in the morning.
“It’s not just what we eat, but also our sleep which influences the amount of energy we burn or store as fat,” she says. “Regularity of habits such as eating and sleeping are very important for general health.”
Nocturnal snacking: what are the health risks?
If this study informs that it is preferable to snack at the end of the afternoon, it should not be forgotten that this habit is sometimes bad, especially at night. Indeed, it can have adverse effects on health. In addition to weight gainnighttime snacking can compromise your health in other ways. Sleep disorders, digestive discomfort, diabetes, concentration problems… The inconveniences to which you expose yourself the next day or in the longer term are numerous. “Eating at night involves first of all the disruption of the appetite hormones ghrelin and leptin”, warns Raphaël Gruman, nutritionist and author of I treat myself with mesonutrients.
In effect, to resist overnight fasting, the body produces leptin, the satiety hormone. By day, to keep us awake, metabolism secretes ghrelin, the hormone that promotes hunger. “Between midnight and 5 a.m., you should never eat. And that’s what I always tell my patients, especially those who work at night, explains dietitian nutritionist Alexandra Retion, author of SOS Nutrition. Our body is not designed to be fed at night”.