Body weight homeostat that regulates fat mass independently of leptin in rats and mice

(Sjur Gjøstein Karevoll) #1

http://m.pnas.org/content/early/2017/12/19/1715687114.full

Quite an interesting study where they show that rats and mice lose body weight when implanted with extra weights and how the weight lost is directly correlated to the amount of weight implanted. The weight loss was also caused by decreased food intake, which indicates that appetite was decreased and therefore that the weight-bearing lower extremities are communicating the weight of the organism with the brain (the study implicates osteocytes i.e. the skeleton is responsible for this).

Speculating, the first thing that comes to mind is that this means sitting increases appetite while standing decreases it independent of other factors. It could also further explain the impact of exercise, which on its own is poor for weight loss but which makes a noticeable difference when combined with dieting. It could suggest that standing exercises like jogging and weight-lifting are better than sitting exercises like cycling and rowing for weight loss, or that the intensity of the exercise doesn’t matter as much. Personally I’m guessing it’s less of the first possibility and more of the second.

Another interesting tidbit is how increased weight also apparently improved the insulin sensitivity of the mice.

Finally I’ll speculate wildly and say that depending on the degree of impact this weight homeostat has on body weight I think it can actually be a significant factor in explaining the rise of the obesity epidemic. Not just are we sitting more and more, but ever increasing body weight also leads to more sitting, creating a downward spiral. Poor diets can also have a similar impact where a bunch of fast food and generally nutrient deficient foods cause diminished general health and decreased inclination towards activity, again leading to more just sitting around and thus increased appetite and weight gain.

I’ll be very interested in further science on this topic, and especially human studies confirming the effect in humans.

(Central Florida Bob ) #2

So that’s saying that if you were to get a scuba diver’s weight belt and wear it around while walking or standing, you’d lose body fat.

Sounds like a simple, cheap experiment we can do. I love cheap, simple experiments, even if they are N=1.

(Sjur Gjøstein Karevoll) #3

Hypothetically yes, though I doubt you’d be able to tell using only an N of one due to confounding factors. It should be easily testable in humans though, just get the study participants to wear something heavy for a few weeks while making sure they stay on their feet, compare to people who don’t wear heavy things but still stay on their feet.

(Central Florida Bob ) #4

It’s an entertaining little study, but I’ll wait for it to be confirmed again, perhaps in other animals. Valuable studies would be to compare the strength of this effect (assuming it replicates) to other treatments. The idea is something I speculated on about 30 years ago, which is probably why I’m drawn to it. (I assumed it was in the soles of the feet, not the leg bones).

I was a rather dedicated cyclist for 20-some years, and gained weight during most of it - certainly the last 15 years of it. Is it because I wasn’t putting enough weight on my legs? Or is it because this effect is weak compared to other effects we know of? Note that I’m not talking about slow, barely-peddling, fat tire-cruising-type cycling, I’m talking more like road bike racing (I’d say grand tour racing, but I was nowhere near that level). Cycling like that has to put at least as much pressure on your legs as standing or walking.

(Brian) #5

The idea of wearing body weights while walking for exercise is not new. I don’t have any personal experience with it but have seen a few people do it.

Hikers that carry a large backpack or soldiers carrying large packs and body armor might be groups that could add something to the discussion.

(Central Florida Bob ) #6

Remember “Heavyhands”? Weights you carried while walking or jogging and were supposed to help you lose weight/get fit. Some study came out saying it wasn’t enough extra calories burned to matter and people kind of dropped them (pardon the pun).

In this case, it would be strap on a large weight (they implanted 15% of the body weight) and wear it all day. That would get uncomfortable and unpleasant, but the things we do in the name science(!).

I don’t have dive gear anymore, and never wore that much weight, but it is tempting. Of course, their thesis also says we could get the benefit from standing more and I can stand more than I do.

(Justin Jordan) #7

For what it’s worth, that’s only true if you’re using them wrong (which most people did) - just carrying two pounds in each hand has a fairly negligible effect on calories. But that’s not what Heavyhands actually is - there, you’re meant to be pumping the weights, swinging them to your eye level or above. That actually makes a huge difference.

(Which is a tangent to the topic, since we’re talking about just load)

(Jenn Monaghan) #8

My weight loss had been stalled since October 4th. I got a standing desk on December 18th. I am now down 6 pounds since then. I’m not sure if that’s what broke the stall, but seems like a big coincidence.

(Sjur Gjøstein Karevoll) #9

Actually, unless you are actively pulling yourself into the bike with your arms or were somehow strapped fast to the bike the pressure on your legs would be at most the same as when standing. As long as you’re partially supported by your arms on the handlebar and/or your ass on the seat your feet are carrying less of the weight, even when you’re pedaling.

But yes, there’s lots of questions about how this works. I personally don’t think cycling would come of as somehow “obesogenic”, but it’s possible that it wouldn’t come off better than walking either. If the weight loss comes from decreased appetite then it’s possible that effect is reduced by the increased calorie consumption more intense exercise like cycling has.

(Sjur Gjøstein Karevoll) #10

Actually, I know people who have worn chain mail shirts all day say it’s not really uncomfortable at all. You get used to the weight and eventually it’s like it’s not even there at all, until you take it off and feel a lot lighter that is.

(Todd Allen) #11

A thread in our forums on standing desks inspired me to make the switch. I’ve found it beneficial and it has become habitual. I pretty much only sit now when socializing/eating with other sitters or with vehicles that require sitting which I avoid as much as possible.

After having lost about 30 lbs of weight I bought a 12 lb weighted vest and 10 lbs of ankle and wrist weights. I use the vest somewhat often but not habitually and I only infrequently use the wrist and ankle weights as it takes time and fuss to put them on and take them off and I tire rapidly with them and everything becomes significantly more challenging. I think the weights are beneficial, though I haven’t noticed appetite inhibition from using them but the possibility never crossed my mind and I haven’t looked for that effect either.

Originally I planned to slowly increase the weights, especially as I continued to lose more weight but I haven’t done so. In part because they are more challenging to habitualize too then merely using a standing desk. But this thread has inspired me to redouble my efforts to incorporate these weights into my daily routine.