Is there a body weight set point?

[EiFit91]

https://sigmanutrition.com/episode391/

Found this recent podcast interesting, maybe others here will as well.

They discuss different theories of body weight/body mass regulation, including the «set point», «settling point» and «dual intervention point» model. I had personally heard of the first two before but was unaware of the «dual intervention point model». It posits that there is a zone of «biological indifference» within which environmental factors drive changes in body weight, and physiological regulation of body weight becomes dominant only when you exceed an «upper intervention point» or when you go below a «lower intervention point». These two intervention points vary across individuals.

[AdamWW]

https://sigmanutrition.com/episode391/

Found this recent podcast interesting, maybe others here will as well.

They discuss different theories of body weight/body mass regulation, including the «set point», «settling point» and «dual intervention point» model. I had personally heard of the first two before but was unaware of the «dual intervention point model». It posits that there is a zone of «biological indifference» within which environmental factors drive changes in body weight, and physiological regulation of body weight becomes dominant only when you exceed an «upper intervention point» or when you go below a «lower intervention point». These two intervention points vary across individuals.

I believe there is sufficient evidence that there is a 'set point range', moreso than a 'set point' per se.

This is, of course, possible to manipulate via certain dietary and lifestyle choices to some degree, but in most cases we do observe that individuals tend to hover within a particular range of weights/body compositions unless they adopt changes to lifestyle/activity/diet composition.



For example, someone may have a 'set point range' of 13-17% BF, and in order to go ABOVE that they would need to do one or some of the following:

- Reduce activity
- Increase the palatability and/or calorie-density and/or processing of their common foods
- Apply certain medications
- Suffer some kind of trauma to trigger chronic over-consumption

Even still, genetics come into play, as we do now understand there are varying levels of leptin sensitively and inherited fat cell concentrations that effect us indefinitely.

There's even that 'obesity gene' thing.

[EiFit91]

I believe there is sufficient evidence that there is a 'set point range', moreso than a 'set point' per se.

This is, of course, possible to manipulate via certain dietary and lifestyle choices to some degree, but in most cases we do observe that individuals tend to hover within a particular range of weights/body compositions unless they adopt changes to lifestyle/activity/diet composition.



For example, someone may have a 'set point range' of 13-17% BF, and in order to go ABOVE that they would need to do one or some of the following:

- Reduce activity
- Increase the palatability and/or calorie-density and/or processing of their common foods
- Apply certain medications
- Suffer some kind of trauma to trigger chronic over-consumption

Even still, genetics come into play, as we do now understand there are varying levels of leptin sensitively and inherited fat cell concentrations that effect us indefinitely.

There's even that 'obesity gene' thing.

Do you think it is body weight or body fat percentage that is subject to physiological regulation?

It seems that people sometimes refer to one and sometimes the other in discussions on this topic. I noticed that this isn’t entirely clear even in the academic papers. For instance I looked at one that had «body weight or body fatness» at the y-axis!

[AdamWW]

Do you think it is body weight or body fat percentage that is subject to physiological regulation?

It seems that people sometimes refer to one and sometimes the other in discussions on this topic. I noticed that this isn’t entirely clear even in the academic papers. For instance I looked at one that had «body weight or body fatness» at the y-axis!

There probably isn't a meaningful distinction for the general population: unless someone is adding a bunch of muscle mass in a short period, it's going to be almost all a change in BF that determines weight.

If we normalize for the lean mass component (in other words, it's not part of the scenario we're using to determine if or if not the set-point-range theory is true) then I think it is almost entirely BF related, not bodyweight.




Bodyfat is the major regulator/secretor or leptin, which is essentially at the core of almost all hunger-driven actions (eating, food seeking...), so that is largely what determines the outcome of bodyfat.

Not the only factor, but a major one.

[EiFit91]

There probably isn't a meaningful distinction for the general population: unless someone is adding a bunch of muscle mass in a short period, it's going to be almost all a change in BF that determines weight.

If we normalize for the lean mass component (in other words, it's not part of the scenario we're using to determine if or if not the set-point-range theory is true) then I think it is almost entirely BF related, not bodyweight.




Bodyfat is the major regulator/secretor or leptin, which is essentially at the core of almost all hunger-driven actions (eating, food seeking...), so that is largely what determines the outcome of bodyfat.

Not the only factor, but a major one.

What I had in mind was a scenario where someone has a lower limit set point at say 15%, and cannot sustain a leaner body composition. Suppose they now add a lot of lean tissue and at the old body weight they would now be 12%. If it’s body fat percentage that drives the regulation, then this person would now cut down to his old weight - that he previously sustained - and find that he now cannot sustain that weight. That just seems counterintuitive to me.

I know that when people go below 10% hunger goes crazy but as long as we are discussing the healthy range it makes sense to me that it would be body weight and not body fat % that is settled on?

[Tommy W.]

the hypothalamus will set the set point through hunger manipulation

[AdamWW]

What I had in mind was a scenario where someone has a lower limit set point at say 15%, and cannot sustain a leaner body composition. Suppose they now add a lot of lean tissue and at the old body weight they would now be 12%. If it’s body fat percentage that drives the regulation, then this person would now cut down to his old weight - that he previously sustained - and find that he now cannot sustain that weight. That just seems counterintuitive to me.

I know that when people go below 10% hunger goes crazy but as long as we are discussing the healthy range it makes sense to me that it would be body weight and not body fat % that is settled on?

It's not that they CANNOT sustain it; it just gets VERY difficult because again: hormones.

10% is also not a hard cut-off point for every man on the planet, it's kind of a generalization and actually I think most people start to feel added hunger higher than 10%... probably closer 12-13% or so, which again depends on food choices, lifestyle, and so on.

Im also not fully understanding your hypotheitcal:
"someone has a lower limit set point at say 15%, and cannot sustain a leaner body composition. Suppose they now add a lot of lean tissue and at the old body weight they would now be 12%. If it’s body fat percentage that drives the regulation, then this person would now cut down to his old weight - that he previously sustained - and find that he now cannot sustain that weight. That just seems counterintuitive to me."

In this scenario, 15% is below the lower end of the bodyfat set range (which means they will be experiencing a significant shift in hunger and energy-sparing adaptations), so dieting to that would have already sucked for them.

Someone who is at their lower-level of the range is going to have a VERY hard to recomping to 12% (which is what you're describing)... recomp is highly, highly unlikely if you're already so low on energy at 15%.... you're really just cutting.

Im not sure why you'd say they would 'cut down' to their old weight, because that 'old weight' is THE SAME weight... they just recomped.



To put it simply:

A) 180 at 15% = 157.25lb lean, 27.75lb fat
B) 180 at 12% = 158.4lb lean, 26.6lb fat

State (B) is not adding a 'lot' of lean tissue... it's a very small change.

But again, what do you mean they 'cut down' to their old weight? The weight is the same: 180lb. They just changed the BF%, and that same person is now going to be hungrier, more tired, and weaker if their lower threshold was 15% for optical wellbeing.

[EiFit91]

It's not that they CANNOT sustain it; it just gets VERY difficult because again: hormones.

10% is also not a hard cut-off point for every man on the planet, it's kind of a generalization and actually I think most people start to feel added hunger higher than 10%... probably closer 12-13% or so, which again depends on food choices, lifestyle, and so on.

Im also not fully understanding your hypotheitcal:
"someone has a lower limit set point at say 15%, and cannot sustain a leaner body composition. Suppose they now add a lot of lean tissue and at the old body weight they would now be 12%. If it’s body fat percentage that drives the regulation, then this person would now cut down to his old weight - that he previously sustained - and find that he now cannot sustain that weight. That just seems counterintuitive to me."

In this scenario, 15% is below the lower end of the bodyfat set range (which means they will be experiencing a significant shift in hunger and energy-sparing adaptations), so dieting to that would have already sucked for them.

Someone who is at their lower-level of the range is going to have a VERY hard to recomping to 12% (which is what you're describing)... recomp is highly, highly unlikely if you're already so low on energy at 15%.... you're really just cutting.

Im not sure why you'd say they would 'cut down' to their old weight, because that 'old weight' is THE SAME weight... they just recomped.



To put it simply:

A) 180 at 15% = 157.25lb lean, 27.75lb fat
B) 180 at 12% = 158.4lb lean, 26.6lb fat

State (B) is not adding a 'lot' of lean tissue... it's a very small change.

But again, what do you mean they 'cut down' to their old weight? The weight is the same: 180lb. They just changed the BF%, and that same person is now going to be hungrier, more tired, and weaker if their lower threshold was 15% for optical wellbeing.

I didn't have in mind someone staying at the same weight and recomping, I had in mind a guy who is currently sustaining 15% at 180 lbs. I assumed that was the lowest weight he could sustain long term. He then does a bulk, maintaining his body fat percentage (or maybe it increases, doesn't really matter). Then when he cuts down to 180 lbs again, he is at 12%. If BF% is the only thing that determines the set point as you suggest, he will now not be able to sustain the body weight that he previously was able to sustain. So after the cut, he will end up drifting upwards to a higher body weight.

I don't think the math above checks out, both of those examples seem to be about 15% to me (15.4% and 14.8%). When I compute it I get that to go from 180 at 15% to 180 at 12% he would need to add about 5 pounds of lean tissue. For a guy of average height that seems like a lot of lean tissue as he would realistically already have several years of lifting experience.

[AdamWW]

I didn't have in mind someone staying at the same weight and recomping, I had in mind a guy who is currently sustaining 15% at 180 lbs. I assumed that was the lowest weight he could sustain long term. He then does a bulk, maintaining his body fat percentage (or maybe it increases, doesn't really matter). Then when he cuts down to 180 lbs again, he is at 12%. If BF% is the only thing that determines the set point as you suggest, he will now not be able to sustain the body weight that he previously was able to sustain. So after the cut, he will end up drifting upwards to a higher body weight.

I don't think the math above checks out, both of those examples seem to be about 15% to me (15.4% and 14.8%). When I compute it I get that to go from 180 at 15% to 180 at 12% he would need to add about 5 pounds of lean tissue. For a guy of average height that seems like a lot of lean tissue as he would realistically already have several years of lifting experience.

OK I see what you're saying now I think.

But my numbers are accurate:

180 * .88 = 158.2lb ... that is for 12% BF

180 * .85 = 157.25lb. .. that is for 15% BF


158.2 - 157.25 = .95lb of lean tissue gained (NOT 5lbs as you said). It's barely anything in terms of % of total weight but it means a lot for an advanced lifter.


You have to keep in mind that 12% is, in fact, a lot leaner than 15% especially in how it will FEEL if someone's set range bottoms out at 15%... you're going 3 percentage points below it. That's a lot.


That same person with the added muscle would be 186.1lb at 15% bodyfat.


I know it doesn't seem like like much, but again, you're assuming 15% is the very lowest possible number that exists wherein they don't start feeling and performing poorly... then you're stripping away 6lbs of fat from it...

6lb's is nothing if they're 25%... but not if they're 15%

[desslok]

From what I have experienced training people for 30 years, there is a floating set point-ish. If you want to change it you have to maintain the new point for several months to a year. Kind of similar to standard of living. If a guy making $30k per year gets a raise to $50k, he will have extra money for a very short time but will quickly adjust his standard of living to his new salary. If he later on got a raise to $100k, he would have extra money for a while, but soon afterwards his standard of living would again adjust to his new salary and he would be living paycheck to paycheck like he was at $30k.

[AdamWW]

From what I have experienced training people for 30 years, there is a floating set point-ish. If you want to change it you have to maintain the new point for several months to a year. .

Yup, that's very consistent with my experience too, which does require some of the changes I mentioned before which are kind of inherently present in the lifestyle changes required to lose the weight/fat in the first place.

The methods a person uses to lose weight (changes in food choice, activity, social environment) are all important factors.

There's very few people out there who are at very high 'set ranges' who eat nutrient-dense, primarily whole food based diets, exercise regularly, etc.

[CommitmentRulz]

O

But my numbers are accurate:

180 * .88 = 158.2lb ... that is for 12% BF

180 * .85 = 157.25lb. .. that is for 15% BF


158.2 - 157.25 = .95lb of lean tissue gained (NOT 5lbs as you said). It's barely anything in terms of % of total weight but it means a lot for an advanced lifter.

Math error.

180 * .88 = 158.4

180 * .85 = 153

So a 5.4 pound difference in lean mass. So with weight remaining the same, that's a loss of 5.4 pounds of fat and a gain of 5.4 pounds of lean tissue.

[AdamWW]

Math error.

180 * .88 = 158.4

180 * .85 = 153

So a 5.4 pound difference in lean mass. So with weight remaining the same, that's a loss of 5.4 pounds of fat and a gain of 5.4 pounds of lean tissue.

Oh weird... i think my phone calculator must have been storing something in memory.

Either way, it's really a matter of BF% at the end of the day

[Heisman2]

In general the literature suggests the body fights weight loss pretty hard but not weight gain. There is a mild tonic inhibition of hunger as body fat increases but eventually when enough fat mass is gained this goes away and people continue to gain more weight until age 60 or so. I think the fact that most of society is continuing to gain weight argues against a set point of any sort.

On the flip side there likely is a lowest body weight, in my mind dictated by both lean body mass and body fat percentage, that most people can go before it becomes very difficult to decrease further.

[AdamWW]

In general the literature suggests the body fights weight loss pretty hard but not weight gain. There is a mild tonic inhibition of hunger as body fat increases but eventually when enough fat mass is gained this goes away and people continue to gain more weight until age 60 or so. I think the fact that most of society is continuing to gain weight argues against a set point of any sort..

I imagine part of that is due to environment but also that the negative feelings of being overfat or eating despite a lower level of hunger are less uncomfortable than those experienced when bodyfat is too low.


Most people 'have room for dessert'... but that's also probably related closely to food choices too.

[EiFit91]

In general the literature suggests the body fights weight loss pretty hard but not weight gain. There is a mild tonic inhibition of hunger as body fat increases but eventually when enough fat mass is gained this goes away and people continue to gain more weight until age 60 or so. I think the fact that most of society is continuing to gain weight argues against a set point of any sort.

On the flip side there likely is a lowest body weight, in my mind dictated by both lean body mass and body fat percentage, that most people can go before it becomes very difficult to decrease further.

What do you think about the dual intervention point idea? I think that could potentially accommodate what you write, but the proponents of the idea would have to hold that environmental factors are still the primary driver of weight gain as most people are within the zone of biological indifference and below their upper intervention point. And the model would predict that at some point weight should stop increasing as everyone eventually reaches their upper intervention point.

Since you write «lowest body weight» dictated by both lean mass and body fat percentage, would that imply that the more lean mass you gain, the easier it should be to maintain a leaner physique than before? So for instance, a guy who cannot sustain 12% at 170 lbs would find it slightly easier to sustain 12% at 180 lbs?

[Heisman2]

I think there is a zone of biological indifference and that the environment is the key driver. I don't think there is an upper limit. If it was then adults wouldn't continue to typically gain weight, but they do. At least that is how I see it.

I think it would be slightly easier to sustain 12% at a higher body weight as you'll have more total fat but I cannot make an evidence-based argument for this. My rationale is that there will be a need for some essential fat in the body for various organ-specific fat depots and the higher total amount of fat beyond that for the heavier person will send more leptin or other adipokines to make it a bit easier.

[snailsrus]

I don’t know how relevant this may be to the thread, but lower body + lower body weight, say sub 10% bf and a low bmi of sub 20-18 generally can drop phosphorus levels and affect hunger

I’ve noticed initial drops in bf and or weight, the longer the amount of time they are maintained hunger levels adjust

As for genetic set point for bf % I think another factor is the fat cells you have accumulate before puberty can play a factor. This is the only time the body can create /gain more fat cells as I understand. After puberty they can shrink or expand but not necessarily create more. Which could affect hunger and bf % set points as an adult?

[EiFit91]

I don’t know how relevant this may be to the thread, but lower body + lower body weight, say sub 10% bf and a low bmi of sub 20-18 generally can drop phosphorus levels and affect hunger

I’ve noticed initial drops in bf and or weight, the longer the amount of time they are maintained hunger levels adjust

As for genetic set point for bf % I think another factor is the fat cells you have accumulate before puberty can play a factor. This is the only time the body can create /gain more fat cells as I understand. After puberty they can shrink or expand but not necessarily create more. Which could affect hunger and bf % set points as an adult?

This makes sense to me. When I cut «recent fat» accumulated during my 20s it’s relatively easy. When I try to go below the weight I was in my late teens and cut some of the «old fat» it gets way harder. And that is fat that I accumulated during my teens when I was still undergoing puberty.

[SuffolkPunch]

The recent talk I've seen on TV about ultra processed foods and their effect on appetite signalling (to the point of actually changing brain chemistry) probably has the effect or raising set points... interesting but I don't have the bandwidth to look at it in depth.

[Heisman2]

The recent talk I've seen on TV about ultra processed foods and their effect on appetite signalling (to the point of actually changing brain chemistry) probably has the effect or raising set points... interesting but I don't have the bandwidth to look at it in depth.

I think that mixes together separate (but related) topics.

1. Body weight/fat/skeletal muscle mass/organ mass control, which can likely be impacted by adipokines such as leptin, myokines from muscle, and who knows what signals from organ tissue.

2. Hunger/appetite/satiation/satiety, all of which have distinct definitions and can be influence by the signals from the prior point but can also be influenced by gut peptides as well as various signalling pathways in the brain (ir, upregulation of the hedonic system or mesolimbic system for emotional eating).

So I think there is certainly overlap between the two but I think ultra processed foods have a much stronger influence on the second point.

[GeneralSerpant]

Conservation of energy principles probably dictate that most animals' hunger drives aren't calibrated to live in an environment with too much food, most crucially on a general populous scale. Gold fish are the only ones that come to mind that will eat themselves to death.

[Heisman2]

Not open access, but this review discusses this question in depth and agrees with me that the dual intervention point model is likely not correct: https://pubmed.ncbi.nlm.nih.gov/31494154/