Burning calories through the life span

By John DiTraglia - Contributing Columnist

Ted Kyle’s the best of 2021 list has a report that was missed until now by me since I can’t keep up with my email. It was much acclaimed back in August by other parts of the world that do keep up with their email. (1,2,3,4)

The authors introduce this study by saying, “Total daily energy 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.” But this information is not really new since they basically got it together by googling it. They used data from prior work that measured human body energy burning by the doubly labeled water method for 6,421 males and females aged 8 days to 95 years, from 29 countries. The doubly labeled water method is the gold standard for measuring energy burning in a living body. Total energy expenditure during daily living (TEE) and energy expenditure during periods of being a complete couch potato (basal energy expenditure, BEE) correlate with things like fat-free body mass and total body mass and sex and age and other factors. When you control for all these things, energy expenditure still varies about 20% from individual to individual. That’s a lot of sloppiness that must mean that there are other factors that we have not figured out.

The surprising to many people findings of this report are that size-adjusted energy expenditure, both TEE and BEE, increases a lot, up to 50% higher than adults, from birth to about 1 year of age and then slowly declines from 1 to 20 years and then stays steady until age 60 when it starts declining again. This doesn’t change during pregnancy meaning that the growing fetus is more like the mother than a born baby who’s adjusted energy burning is increasing after birth.

This underlying average situation obviously doesn’t explain anything and may seem to contradict the average increases in obesity that seem to be happening between 20 and 60 and why do old people lose weight while their metabolism corrected for that decrease in body size is going down.

“Life is a game of turning energy into kids,” is the message of the lead author Herman Pontzer. What is also apparent is that whatever those 6,421 people were doing exercise-wise didn’t matter much over all to the constancy of TEE in both males and females. Pontzer et al. have done some also surprising work in the exercise part of this story that we can talk about some more soon. Apparently whatever your brain and liver and kidneys and bones and etc.. are always doing is way more energy consuming than your life’s ambition apart from making babies.

1. https://conscienhealth.org/2021/12/the-ten-biggest-stories-of-2021-in-obesity-and-health/

2. Pontzer H et al. Daily energy expenditure through the human life course. SCIENCE • 13 Aug 2021 • Vol 373, Issue 6556 • pp. 808-812 • DOI: 10.1126/science.abe5017

3. https://conscienhealth.org/2021/08/learning-humility-about-nutrition-and-metabolism/

4. https://www.nytimes.com/2021/08/12/health/metabolism-weight-aging.html

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- [email protected] or phone-354-6605.


By John DiTraglia

Contributing Columnist

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- [email protected] or phone-354-6605.

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- [email protected] or phone-354-6605.