Packing on the poundage? Sorry, suckers: We can’t use middle-age as our excuse for that spread anymore!
A revelatory new study has determined that metabolism, long thought by most of humankind to decline progressively during adulthood, is actually stabilized between the ages of 20 and 60 — when it actually starts tanking.
An international team of killjoy researchers, whose work was published Friday in the journal Science, discovered that metabolism is at its highest in infants — naturally — who burn calories about 50% faster than adults. That rate declines yearly by about 3% until they reach the age of 20 or so, when metabolism plateaus through middle adulthood. At 60, the slump returns at a depressing rate of about 1% more per year until we drop dead.
What this means: We can no longer blame middle-age as the primary reason for amassing newfound weight. For accuracy, researchers accounted for metabolic differences in volunteers, such as body size muscle to fat composition.
"Metabolic rate is really stable all through adult life, 20 to 60 years old," said study author Herman Pontzer, an associate professor of evolutionary anthropology at Duke University, who spoke to NBC News on Thursday about the research.
Pontzer went on to pontificate about new data that’s likely to send a shiver down the lucrative wellness industry’s collective spine:
"There’s no effect of menopause that we can see, for example. And you know, people will say, ‘Well when I hit 30 years old, my metabolism fell apart.’ We don’t see any evidence for that, actually," said Pontzer. His new book, "Burn" (Avery) is about new frontiers in bariatric health.
As part of a global experiment, 6,400 participants, aged 8 days to 95 years were asked to perform "doubly labeled water" test, in which some of the hydrogen and oxygen atoms were replaced with their isotopes, making their pathway easily traced through urine samples.
"By calculating how much hydrogen you lose per day, and how much oxygen you lose per day, we can calculate how much carbon dioxide your body produces every day," Pontzer explained to NBC News. "And that’s a very precise measurement of how many calories you burn every day, because you can’t burn calories without making carbon dioxide."
The findings, said Pontzer, were a long time coming as scientists now have access to such a large test group.