Sorry, folks. You might not be able to blame that bulging waistline on slowing metabolism as you age. Established wisdom is being unestablished.
A study published in the journal Science says that our metabolism —simply put, the way our bodies convert food to energy — declines about 3% a year after it peaks when we reach our first birthday. That continues until about age 20. At that point, however, metabolism plateaus for roughly the next 40 years before it begins slowing again, although at a miniscule rate — less than 1% a year.
That means chucking out the window, among other myths, the notion that our middle age weight gain is metabolism’s fault. Or that women have slower metabolism than men, making them particularly susceptible to putting on the pounds. Or that menopause reduces it even further.
No, no and no, researchers say. Looks like when we gain weight, it’s because we eat too much. That is, we’re taking in more calories than we’re burning.
These new findings are based on data collected from 6,500 individuals. Investigators noted no obvious difference between the metabolism of men and women after controlling for other factors like body size.
And don’t think the work is the product of a rogue scientist. There are 80 co-authors on the paper and findings are described by some as pivotal in the scientific understanding of how our bodies burn energy. The study’s authors collected data for more than 40 years and shared information for publication.
The investigation has potentially important implications for medicine, among them calculating the right drug doses for patients.
As a final note, envy those 1-year-old babies. Their metabolism, when it peaks, rolls along 50% above the adult rate.