Read on Twitter
Obesity researchers: I'm going to share some ideas for experiments that I think could be important.
I've been mulling this over since I was a postdoc but I'm not in a position to do the experiments myself. I'd be happy to see someone else do them.
I've been mulling this over since I was a postdoc but I'm not in a position to do the experiments myself. I'd be happy to see someone else do them.
Intro: It's clear at this point that adiposity is biologically regulated, and to some degree we understand the mechanism.
The "starvation response" to weight loss that this system generates is a major barrier to weight loss and maintenance.
The "starvation response" to weight loss that this system generates is a major barrier to weight loss and maintenance.
To a large degree, we understand how the regulatory system operates and what its effectors are.
The "starvation response" is caused by ↓↓ leptin, and it causes characteristic changes in energy expenditure, thyroid hormones, satiety, attention to food cues, brain activity, etc.
The "starvation response" is caused by ↓↓ leptin, and it causes characteristic changes in energy expenditure, thyroid hormones, satiety, attention to food cues, brain activity, etc.
In a series of fascinating experiments, Rudy Leibel and Michael Rosenbaum's group has shown that replacing leptin back to the pre-weight-loss level reverses these effects.
https://www.jci.org/articles/view/25977
https://www.jci.org/articles/view/35055
https://academic.oup.com/ajcn/article/95/2/309/4576721
https://www.jci.org/articles/view/25977
https://www.jci.org/articles/view/35055
https://academic.oup.com/ajcn/article/95/2/309/4576721
Clearly, the tendency to regain weight (and all the effector mechanisms that comprise it) is related to the activity of this homeostatic system. And we have ways to measure its activity via the effectors.
This also probably affects the ease of weight loss to begin with.
This also probably affects the ease of weight loss to begin with.
My idea is to do basically these same experiments, but with other variables that could plausibly impact the energy homeostasis system.
We already have candidate variables from other lines of investigation: protein, other macronutrients, food reward, exercise, stress, sleep, etc.
We already have candidate variables from other lines of investigation: protein, other macronutrients, food reward, exercise, stress, sleep, etc.
It would be extremely valuable to test the effect of variables that could be used in an individual or clinical setting.
Imagine if we had hard, quantitative data on the degree to which common diet and lifestyle variables (or even drugs) impact the "starvation response".
Imagine if we had hard, quantitative data on the degree to which common diet and lifestyle variables (or even drugs) impact the "starvation response".
When I wrote my book, I used indirect evidence to identify variables I think are likely to dampen the starvation response, which I think is a determinant of sustainable weight loss.
I'd much rather have direct evidence.
I'd much rather have direct evidence.
To get a bit more specific, one interesting idea would be to test the impact of food reward. Compare the effects of tasty normal food, vs. the exact same amount of the exact same food consumed in unappealing smoothie form. Measure how it impacts the effectors.
If food reward isn't your cup of tea, this could be done using diets differing in protein, or other variables.
Feel free to contact me if you want to discuss these ideas further.
Feel free to contact me if you want to discuss these ideas further.
