-Diablo's Journal, 13 May 22

CHANGES IN METABOLIC RATE ARE UNLIKELY TO BE A PRIMARY CAUSE OF SLOW OR NO WEIGHT LOSS⁠ ⁠ This is from a webinar in the Weightology Research Review. In this webinar, I cover the impacts of metabolism and NEAT on body weight.⁠ ⁠ While metabolism does slow down with weight loss, there's a limit to how much it can slow down. In this well controlled study, there was a 12% reduction in resting metabolic rate after 10% weight loss, after controlling for changes in body weight and fat-free mass. However, metabolism didn't really change much further after 20% weight loss.⁠ ⁠ Thus, reductions in metabolism are not a big factor in slower-than-expected weight loss, particularly after large reductions in body weight. Typically, reductions in energy expenditure with more weight loss come primarily from physical activity energy expenditure, mainly non-exercise activity thermogenesis (NEAT).⁠ ⁠ The good news is that, unlike metabolic rate, NEAT is something we have some control over. This means deliberate and conscious increases in overall physical activity to help battle this reduction in NEAT. In fact, the research shows that high physical activity levels are very important for preventing weight regain after weight loss.⁠ ⁠ For more video presentations and other research reviews, check out the Weightology Research Review. We review 6+ studies per month, and subscribers get access to all back content. 

Thank you for posting this, Diablo. Unless your thyroid is all out of whack, it's more likely that you're being a lazy couch potato. Thin people can eat a bunch because they're constantly moving around during the day (NEAT). I intentionally walk to & from work, and I don't drive to run errands -- they're all done by walking and carrying stuff back -- so I keep my NEAT high and steady throughout the week. No weight loss is because you're eating more than you're burning each day. Pretty straight forward. 

Good news, isn't it? People exaggerate how much less you'll have to eat to maintain a lower body weight. It's less as a baseline, but it's not normal to have to eat the same calories to lose weight and maintain a loss.  

And before someone brings up the Pontzer paradox to suggest that increased activity doesn't burn calories - the compensations (slowing down during other daily activities, not wanting to move the rest of the day or on rest days) only occurs at EXTREMELY high levels of activity, like, crazy levels that athletes perform at. For the average person sitting on the couch who isn't very active, more activity to a moderate or even high level, will help with weight loss or to maintain it. 

On a very similar note - my coach was just telling me about a paper that claims/demonstrates the same thing about aging. Metabolism and energy requirements really don't "slow down" until well into our 80's. People's activity levels tank, and that's what causes most "age-related weight gain". ON that note, I'll have to check out Weightology. Great post. 

Given the same weight, muscle to fat ratio, and activity level, I don't see how one person can be so much more efficient than another so it makes sense. A "slow" metabolism means your body is more efficient at calorie expenditure suggesting a healthier body and a better chance of survival. So you can see how that doesn't make sense. An obese unhealthy person advising that they have a slow metabolism so they can't lose weight on less than 2k calories a day are just underreporting intake. Plain and simple. 

This is contrary to that biggest loser study found? Maybe because the losses were slower? 

Liv I can't remember exactly where I read it now but there has been some challenging of studies that claimed that RMR decreased much more than expected. I think there have been the usual issues with people underreporting calories and overreporting activity. Can't remember exactly. 

Bananas - as a former really skinny person, even in my sleep my RMR was sky high lol. I used to gain weight even on keto just from calories alone though. It took me forever to get my metabolism under control. All that to say, I think body size doesn't have so much to do with it as amount of movement. I would actually think an overweight person with the same amount of activity as a thin person would have a higher metabolism because it's more effort to move a bigger body. Exercise is exercise though, no? Why does size matter regarding RMR?  

I dunno, Chris. I've always been active and thin (except for the 2 years at this one job where I grazed on garbage all day and destroyed my careful CICO balance). Maybe age factors into it somehow, since we do collect injuries over the years, and arthritis, tendonitis, sciatica -- things like that that cause us to slow down and be more careful and deliberate with our movements. And I assume that you're comparing 2 people of the same height, since longer bones and muscles and bigger organs take more energy to lift & move.