Our Metabolism

Blaming those extra pounds on a slowing metabolism as you age? Not so fast.

A new international study counters the common belief that our metabolism inevitably declines during our adult lives. Well, not until we’re in our 60s, anyway.

Researchers found that metabolism peaks around age 1, when babies burn calories 50 percent faster than adults, and then gradually declines roughly 3 percent a year until around age 20. 

From there, metabolism plateaus until about age 60, when it starts to slowly decline again, by less than 1 percent annually, according to findings published Thursday in the journal Science.

To tease out the specific impact of age on metabolism, the researchers adjusted for factors such as body size (bigger bodies burn more calories overall than smaller ones) and fat-free muscle mass (muscles burn more calories than fat).

“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 and author of “Burn,” a new book about metabolism. 

“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.”

Pontzer and colleagues studied a database of more than 6,400 people, ages 8 days to 95 years, from 29 countries worldwide who had participated in “doubly labeled water” tests. 

With this method, individuals drink water in which some of the hydrogen and oxygen have been replaced with isotopes of these elements that can be traced in urine samples.  READ MORE

For Healthy-Minded Folks...

Several months ago, I decided that I would count my daily intake of calories in the hopes that I could shed/lose a dozen pounds or so that I had previously gained because of taking steroids with my chemo for over ten years (actually, it was 30 pounds).  My research revealed that if a person, my gender, age, and weight consumed over 2500 calories each day, I would gain weight and if I consumed 2000 to 2500 calories I would maintain my weight, but if I consumed 1500 to 2000 calories I would lose weight.  My initial goal was to see if I could limit my intake of calories from 1500 to 2500...

Over the course of the first month, it was discovered that consuming between 2000 to 2500 was relatively easy...  so, reducing that by up to 500 did not seem like it would be that difficult.  To help me with this process, I created a calorie counter (see below) thinking that if I recorded each day I would be more motivated to continue...



During the April, I decided to add an exercise routine to my calorie counting and started peddling on a stationary bike for 20 minutes each day.  After a week, I increased it to 30 minutes and then after another week, I increased it to 40 minutes.  After another week had passed on my 40 minute bike routine, I would peddle for 20 minutes, walk a 1/4 mile and then peddle for another 20 minutes.  A week later, it was peddle for 20, walk for 1/2 mile, and peddle for 20 again.  Then, a week after that it was peddle for 20, walk for 1/2 mile, peddle for 20, walk for 1/2 mile.

I have reached my limits so I am not going to increase anything for several weeks remaining at 40 minutes peddling at a moderate speed and walking 1 mile at a speed of 3.0...  what is interesting here, at least to me, is the fact that because of my weight, my treadmill does not operate very well at speeds lower than 3.0...  so, I have been at that speed from the getgo.  3.0 is a 20 minute mile.  BTW, my little exercise routine burns 350 calories (40 minutes peddling - 1 mile walking at 3.0)