Surely, at some point in your life, you’ve heard that after a certain age you would have to reduce the amount of food you eat. “The metabolism slows down,” they say. Or, for teenagers, the warning is the opposite: “Let them eat because they burn the calories quickly. ” There are several concepts about the best age to get fat or lose weight shared for decades. There is, for example, the classic excuse for someone who gains a few extra pounds in middle age: “at that age, my metabolism is no longer the same as it was at 20” or even “I can’t lose weight, it’s my fault slow metabolism that no longer burns calories. Age thing, there’s no way”. But these usual pretexts that weight gain at a certain stage of life is the responsibility of metabolism – a set of all chemical reactions that take place in the body’s cells and transform food into energy – fell apart after the publication of an article in the journal Science revealing that the burning of calories does change over time, but not in the way we imagined.
The conclusions presented in the article show that the oscillations in metabolism are divided into four phases: in the first year of life, the burning of calories reaches its peak, accelerating until it is 50% above the rate of an adult; from 1 to 20 years, the rate of metabolism gradually drops by about 3% per year; from 20 to 60 years of age, it remains stable and, after 60 years of age, it decreases by around 0.7% per year. That is, no more excuses for teenagers who overeat, believing that their bodies will take care of the excess calories, and also for those who put on too much weight in midlife and blame their metabolism. “This study really highlighted that, on average, adults have similar metabolic rates between the ages of 20-60, but there is still a lot of individual variability between people. Of course, healthy eating and exercise are the cornerstones of healthy weight maintenance, and this study doesn’t rule out any of that,” said Peter T. Katzmarzyk, associate executive director for Population and Public Health Sciences at the Pennington Biomedical Research Center, to LOOK. “To achieve your weight loss goals, limit your calorie intake and engage in physical activity.”
According to the survey, the total daily energy expenditure rapidly accelerates in newborns, and is up to twice the average value of adults. But after a year of life, it drops to levels that, between the ages of 20 and 60, remain stable. After that age, it starts to decrease until reaching lower levels in the last years of life. “This is because the way the body consumes energy decreases with age. The slower metabolism causes us to burn fewer calories even with exercise, as the cells consume nutrients more slowly and tend to reserve fat in case of need”, explains Juliano Burckhardt, nutritionist and geriatrician, full member of the Brazilian Association of Nutrology ( ABRAN), from the International Colleges for Advancement of Nutrology and the Brazilian Society of Geriatrics and Gerontology.
Another relevant factor in the research is to show that metabolism has nothing to do with gender. There are no real differences between men’s and women’s metabolic rates if the conditions are similar, says the study, which collected information from 6,500 people aged 8 days to 95 years. “These changes call attention to human development and aging and should help in nutrition and health criteria throughout life”, attests Herman Pontzer, from Duke University, in the United States, and the main author of the work.
The 4 phases of human metabolism:
Up to 1 year old: Calorie burning is at its height, accelerating to 50% above the adult rate.
From 1 to 20 years: Metabolism gradually slows down by about 3% per year.
From 20 to 60 years old: Remains stable.
After 60 years of age: decreases around 0.7% per year.