What We Know About Metabolism May Be All Wrong, a Pivotal Study Finds
We think it's good to eat less as we grow older, because we've been told that our bodies burn calories at a slower rate with age. Women have been told their metabolism is slower than men, and that menopause only makes it worse.
Turns out all that we know about metabolism might be wrong.
According to a new study published in the journal Science, middle aged people have the same calorie-burning capacity as 20-year-olds.
The metabolism peaks at the age of one, is stable from 20 to 60, and then declines, the findings suggest.
“This study reveals that there are lots of misconceptions about how metabolic rate changes with age,” said Prof John Speakman, co-author of the research, of the University of Aberdeen was quoted as saying by The Guardian.
About the Study
The researchers used data from nearly 6,500 people, ranging in age from 8 days to 95 years, to see how factors like age, size, and gender affect metabolism.
The researchers used a technique called 'a doubly labeled water test' to measure their energy expenditure. It measures calories burned by tracking the amount of carbon dioxide a person exhales during daily activities.
They discovered that there are four distinct periods of metabolic life.
Infancy to age 1: The calorie burning is at its peak, accelerating until it is 50 percent above the adult rate.
Age 1 to about Age 20: metabolism gradually slows by about 3 percent a year.
Age 20 to 60: No change in metabolism.
After age 60: It declines by about 0.7 percent a year.
No Surge in Metabolism During Puberty or Pregnancy
The researchers also found that there are no differences between the metabolic rates of men and women.
The study also found that there was no surge in metabolism during either puberty or pregnancy. There was also no slowdown around menopause.
The findings also throw light on the importance of nutrition during childhood and how malnutrition during the early years could have long-lasting consequences.
"When people talk about metabolism, they think diet and exercise - but it is deeper than that, we are actually watching your body, your cells, at work," Prof Herman Pontzer, from Duke University, was quoted as saying by BBC News.
The findings of the study could also have implications in medicine, the researchers said.
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