The Science of the Middle-Age Spread By Mrs Vera West

Most middle-age persons blame their gaining of weight upon their alleged slowed down metabolism. However, the latest scientific research indicates that there are not statistically significant changes to human metabolism, at least until about age 60 years. Life style factors are now thought to be more important, such as diet, the quantity and quality of food eaten and probably reduced levels of exercise. So, this is good news for the middle-aged, and no more excuse for slackness!

https://www.newscientist.com/article/mg25333774-900-middle-age-spread-isnt-down-to-metabolism-but-we-know-how-to-beat-it/?utm_source=nsnew&utm_medium=email&utm_campaign=NSNEW_100322

“FEW of life’s milestones are as unappealing and unceremonious as arrival in middle age. Our skin becomes noticeably looser, grey hairs more numerous and, of course, our clothes typically start to feel a bit tighter – especially around the waist.

The last of these is known as middle-aged spread, the commonly accepted idea that we start to pack on the pounds around the abdomen as we get older. This excess weight is said to be easy to put on and harder to shift than when we were younger, the thinking being that our once-perky metabolism gets sluggish with age. We can no longer get away with as much, and our efforts to ditch the belly with diet or exercise become a losing battle.

So far, so miserable. But then, last July, a study of over 6000 people around the world blew the idea out of the water. It showed that metabolism stays remarkably stable as we age, at least until our 60s. “The amount of calories you burn per day from age 20 to 60 remains about the same,” says Herman Pontzer at Duke University in North Carolina. “We’ve shown that you have much less control over metabolism than we thought.” The idea that your metabolism is just as active as you approach your 60s as it was in your 20s should be welcome news for anyone nearing middle age – usually defined as the period from 45 to 65 years of age – and facing the dreaded spread. But it leaves a burning question: if metabolism isn’t to blame, then what is? And what can be done?”

https://www.science.org/doi/full/10.1126/science.abe5017

Daily energy expenditure through the human life course

HERMAN PONTZER HTTPS://ORCID.ORG/0000-0003-2397-6543 YOSUKE YAMADA HTTPS://ORCID.ORG/0000-0002-4284-6317 HIROYUKI SAGAYAMA HTTPS://ORCID.ORG/0000-0002-9040-7650 PHILIP N. AINSLIELENE F. ANDERSEN HTTPS://ORCID.ORG/0000-0003-0236-1558LIAM J. ANDERSONLENORE ARAB HTTPS://ORCID.ORG/0000-0001-8452-7202ISSAAD BADDOU HTTPS://ORCID.ORG/0000-0001-9158-2621KWEKU BEDU-ADDO[...]IAEA DLW DATABASE CONSORTIUM§ +74 authors Authors Info & Affiliations

SCIENCE • 13 Aug 2021 • Vol 373, Issue 6556 • pp. 808-812 • DOI: 10.1126/science.abe5017

“A lifetime of change

Measurements of total and basal energy in a large cohort of subjects at ages spanning from before birth to old age document distinct changes that occur during a human lifetime. Pontzer et al. report that energy expenditure (adjusted for weight) in neonates was like that of adults but increased substantially in the first year of life (see the Perspective by Rhoads and Anderson). It then gradually declined until young individuals reached adult characteristics, which were maintained from age 20 to 60 years. Older individuals showed reduced energy expenditure. Tissue metabolism thus appears not to be constant but rather to undergo transitions at critical junctures. —LBR

Abstract

Total daily energy expenditure (“total expenditure”) reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass–adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.”

https://www.dailymail.co.uk/health/article-9920355/What-really-causes-middle-age-spread-beat-it.html