New meta-analysis on energy intake and muscle growth

[EiFit91]

Very interesting in light of previous forum discussions.

Link: https://onlinelibrary.wiley.com/doi/10.1111/sms.14075

Summary by Menno Henselmans:
https://mennohenselmans.com/energy-d...meta-analysis/

One important point emphasized by Menno: They find that BMI correlates negatively with muscle growth. One possibility is that having a high BF% impairs muscle growth. Another is that high BMI lifters in the study sample could be more experienced and closer to their genetic potential (haven’t read the text in detail and it may be that this is discussed). Menno also mentions this as a possible interpretation.

I found the following figure neat and interesting:



It seems to me that while a large deficit negatively influences muscle growth, the effect size is highly dependent on the size of the deficit. With a small deficit, muscle loss is rare and muscle growth often happens. With a very small deficit muscle growth seems to be the norm. It would be interesting to see the above graph restricted to lifters who are already experienced with resistance training.

[EliKoehn]

Did I hear you right?

You found the graph about energy expenditure NEAT?

[EiFit91]

Did I hear you right?

You found the graph about energy expenditure NEAT?

LOL not this again

[Heisman2]

One thing to note is that they calculated the energy deficit from the change in body fat. This was presumably determined by DEXA scans in most if not all studies. So any error in the determination of changes in body fat would have altered the energy deficit calculation.

Also, analysis A had 7 studies, 6 specified the participants were inactive at baseline, and the average age was 60 years old. Analysis B had 52 studies, average age 51 +/- 16 years, and only 2 of them had people who were stated to be previously resistance-trained.

Thus, this really looks at beginners alone and in a populated skewed to being on the older side. They also found no influence of study duration on lean body mass change, which is somewhat concerning for the overall quality of the resistance training interventions and/or the methodology they used to assess changes in lean body mass.

So I'm glad this was published but there is still a lot to learn in this area, I think.

[EiFit91]

One thing to note is that they calculated the energy deficit from the change in body fat. This was presumably determined by DEXA scans in most if not all studies. So any error in the determination of changes in body fat would have altered the energy deficit calculation.

Also, analysis A had 7 studies, 6 specified the participants were inactive at baseline, and the average age was 60 years old. Analysis B had 52 studies, average age 51 +/- 16 years, and only 2 of them had people who were stated to be previously resistance-trained.

Thus, this really looks at beginners alone and in a populated skewed to being on the older side. They also found no influence of study duration on lean body mass change, which is somewhat concerning for the overall quality of the resistance training interventions and/or the methodology they used to assess changes in lean body mass.

So I'm glad this was published but there is still a lot to learn in this area, I think.

Thanks for clarifying. The point about measurement seems very concerning...

That they mostly look at beginners makes it very surprising to me that they found what they found concerning BMI and muscle gain. I would expect overweight beginners to be much more likely to recomp than beginners with a low BMI. But maybe the studies using larger deficits more often featured participants with high BMIs?

[air2fakie]

One thing to note is that they calculated the energy deficit from the change in body fat. This was presumably determined by DEXA scans in most if not all studies. So any error in the determination of changes in body fat would have altered the energy deficit calculation.

Also, analysis A had 7 studies, 6 specified the participants were inactive at baseline, and the average age was 60 years old. Analysis B had 52 studies, average age 51 +/- 16 years, and only 2 of them had people who were stated to be previously resistance-trained.

Thus, this really looks at beginners alone and in a populated skewed to being on the older side. They also found no influence of study duration on lean body mass change, which is somewhat concerning for the overall quality of the resistance training interventions and/or the methodology they used to assess changes in lean body mass.

So I'm glad this was published but there is still a lot to learn in this area, I think.

Thanks for reviewing & elaborating. Tbh not surprised with another study limited to subjects and researchers who prob have little personal experience with fitness.

[desslok]

Did I hear you right?

You found the graph about energy expenditure NEAT?

TEE-hee

[desslok]

Thanks for reviewing & elaborating. Tbh not surprised with another study limited to subjects and researchers who prob have little personal experience with fitness.

Its almost like studies go out of their way to find completely irrelevant participants.

[EliKoehn]

TEE-hee

Haha, you got me with that one lol

[EliKoehn]

Its almost like studies go out of their way to find completely irrelevant participants.

In all seriousness, it might have to do with the inherent limitations of voluntary participation, especially for macroscopic, long-term studies like this. I agree with you, but I assume it will be harder to find a more suitable demographic among people already acquainted with fitness and its principles.

[air2fakie]

In all seriousness, it might have to do with the inherent limitations of voluntary participation, especially for macroscopic, long-term studies like this. I agree with you, but I assume it will be harder to find a more suitable demographic among people already acquainted with fitness and its principles.

Sure, just like it's also hard to administer/control/monitor the actual food & exercise of sedentary, obese test subjects for TDEE / effect of exercise on weight loss studies - but that's not an excuse to only do it solely by secondhand measures when that's literally the heart of the studies.

If a study is going to have such obvious shortcomings, they should be clearly highlighted if they want to appear to be credible.

[EliKoehn]

Sure, just like it's also hard to administer/control/monitor the actual food & exercise of sedentary, obese test subjects for TDEE / effect of exercise on weight loss studies - but that's not an excuse to only do it solely by secondhand measures when that's literally the heart of the studies.

If a study is going to have such obvious shortcomings, they should be clearly highlighted if they want to appear to be credible.

Ah, but then how will they support their barely-employable academic livelihoods without the grant money that such "research" sustains?

[paulinkansas]

Many years ago the Coast Guard wanted to do a test. They got 4 volunteers to go out in a lake in a boat and observe flares shot from a flare gun on the shore. The Coast Guard wasn't testing the visibility of the flares, that was just a ruse. They were really testing the people to see if they would utilize their life vests in an emergency.

The boat was rigged to start sinking when it was out in the lake. There were life preservers in the boat, and they wanted to see if the people in the boat would don the life preservers. The 4 people swam half a mile back to the shore instead of wearing the life preservers.

After the fact, it was discovered the 4 people were on the swim team of a college.

[air2fakie]

Many years ago the Coast Guard wanted to do a test. They got 4 volunteers to go out in a lake in a boat and observe flares shot from a flare gun on the shore. The Coast Guard wasn't testing the visibility of the flares, that was just a ruse. They were really testing the people to see if they would utilize their life vests in an emergency.

The boat was rigged to start sinking when it was out in the lake. There were life preservers in the boat, and they wanted to see if the people in the boat would don the life preservers. The 4 people swam half a mile back to the shore instead of wearing the life preservers.

After the fact, it was discovered the 4 people were on the swim team of a college.

Convenient, would've been unfortunate if they discovered after the fact that none of 4 volunteers could swim.

[desslok]

In all seriousness, it might have to do with the inherent limitations of voluntary participation, especially for macroscopic, long-term studies like this. I agree with you, but I assume it will be harder to find a more suitable demographic among people already acquainted with fitness and its principles.

I think also that people into health/strength/appearance don’t want to take a chance that they may be in the control group. Years ago for a medical condition the doctor asked if I would like to be in a study, I didn’t really know much about studies back then(early 90s), so he explained that I may end up in a control group getting sugar pills. I said hell no, I want the medicine that works. I think it’s the same with muscles, people don’t want to risk being in the group where they lose all of their gainz and their muscles fall off.

[Heisman2]

Regarding BMI, in their meta-regression this was a significant modifier. If you look at Table 1 its coefficient was -0.0243 with a p value of 0.03. With the negative value this implies a higher BMI leads to less LBM gain with RT. However, BMI is the one variable they were hoping to match between the intervention and controls but were not able to (for Analysis B). The energy deficit groups had an average BMI of 32.7 while the non-energy deficit groups had an average BMI of 27.5. Thus, the groups were not matched, and the average BMI was in the overweight or obesity range for both groups, meaning there probably were not that many "fitness lean" individuals. Keep in mind a higher BMI will correlate to some degree with insulin resistance and I expect people with more insulin resistance will have a harder time gaining muscle.

[Tommy W.]

I doubt these studies will ever be accurate. Between not knowing exact daily changing maintenance, including the impossibility of measuring NEAT, not knowing the actual amount of weekly calories the subjects were taking in it will always be an educated guess at best.

[air2fakie]

I doubt these studies will ever be accurate. Between not knowing exact daily changing maintenance, including the impossibility of measuring NEAT, not knowing the actual amount of weekly calories the subjects were taking in it will always be an educated guess at best.

I'm surprised no one found a study saying the larger the deficit, the greater the muscle growth - claiming it's right because the authors are cited, published and presumably experts, and we're all just idiots who base things on old science and real life.

[EiFit91]

I'm surprised no one found a study saying the larger the deficit, the greater the muscle growth - claiming it's right because the authors are cited, published and presumably experts, and we're all just idiots who base things on old science and real life.

Starting to understand what that other guy (Animal something) said about you holding a grudge...

[EiFit91]

Regarding BMI, in their meta-regression this was a significant modifier. If you look at Table 1 its coefficient was -0.0243 with a p value of 0.03. With the negative value this implies a higher BMI leads to less LBM gain with RT. However, BMI is the one variable they were hoping to match between the intervention and controls but were not able to (for Analysis B). The energy deficit groups had an average BMI of 32.7 while the non-energy deficit groups had an average BMI of 27.5. Thus, the groups were not matched, and the average BMI was in the overweight or obesity range for both groups, meaning there probably were not that many "fitness lean" individuals. Keep in mind a higher BMI will correlate to some degree with insulin resistance and I expect people with more insulin resistance will have a harder time gaining muscle.

As always, I need to spread some reputation around before giving it to Heisman2 again.

Do you think insulin resistance is a factor even in trained powerlifters with a high body fat percentage? Is it just related to bodyfat or general fitness level as well?

[air2fakie]

Starting to understand what that other guy (Animal something) said about you holding a grudge...

Sounds like something someone with a grudge would bring up, esp since the average forum reader wouldn't even have connected anything to you. You voluntarily choose interesting company I must say.

As always, I need to spread some reputation around before giving it to Heisman2 again.

I got him for you, as I appreciate logical reasoning and thought whether or not I always agree.

[EiFit91]

Sounds like something someone with a grudge would bring up, esp since the average forum reader wouldn't even have connected anything to you. You voluntarily choose interesting company I must say.



I got him for you, as I appreciate logical reasoning and thought whether or not I always agree.

I just find it amusing that you are so obviously trying to bait me after you accused me of doing the same in the other thread.

[Tommy W.]

I'm surprised no one found a study saying the larger the deficit, the greater the muscle growth - claiming it's right because the authors are cited, published and presumably experts, and we're all just idiots who base things on old science and real life.

Researchers need things to research so these studies keep coming up. There will be no new breakthroughs on these things. The parameters of success in adding muscle and losing fat have a long, ongoing history of what works and what doesn't, whether is anecdotal from person to person or general knowledge that's been with us awhile. I think we're at the point of diminishing returns with the science.

[Heisman2]

As always, I need to spread some reputation around before giving it to Heisman2 again.

Do you think insulin resistance is a factor even in trained powerlifters with a high body fat percentage? Is it just related to bodyfat or general fitness level as well?

I think higher levels of fitness can mitigate the impact of higher levels of body fat on insulin resistance. Having said that... I'm not sure I'd consider some of the larger powerlifters to have decent cardiovascular fitness, lol. I haven't looked for studies evaluating cardiovascular fitness in trained powerlifters who don't specifically do any cardio; I think that would be a fun study to look at.

Whether I agree or disagree with anyone here I generally appreciate everyone's posts when they don't veer too off track into back and forth arguing as that just can derail threads. That's why I try to jump in as quickly as I can prior to that happening. If everyone agreed with everyone else then there wouldn't be any purpose in discussing anything. I generally do learn things from these types of threads when reading differing points of views. Even if those posts don't directly teach me anything just by considering things from a different viewpoint I can make different types of connections. Speaks to the large heterogeneity in the literature for many of these topics that it is possible to throw out lots of conditionals/exceptions/etc.

[air2fakie]

I just find it amusing that you are so obviously trying to bait me after you accused me of doing the same in the other thread.

Actually you had replied directly 3x to statements of mine with some quote trying to refute it, and argued every point under the sun except whether or not what I had said was factually incorrect. Above I was replying to someone else, and stated an actual thought of mine at the time upon reading his comment.

Apologies if I can't comment when you might take it as reflecting poorly on your past posts. No need for everyone here to have to relive it yet again, my bad.

[air2fakie]

Researchers need things to research so these studies keep coming up. There will be no new breakthroughs on these things. The parameters of success in adding muscle and losing fat have a long, ongoing history of what works and what doesn't, whether is anecdotal from person to person or general knowledge that's been with us awhile. I think we're at the point of diminishing returns with the science.

Agree with the bold.

Regardless of their own self-interest, I'm less skeptical than you about whether continuing studies could yield new info that could help smaller, select groups with specific health issues. But wish the studies would be more honest about shortcomings with protocols & limited subject classes, since that would guide future research on improvements, and might dissuade readers from misinterpreting assumptions & results beyond what's in the studies themselves.

No problem with studies if the protocol, data & results are reviewed for the information they actually provide, and don't.

[EliKoehn]

I'm surprised no one found a study saying the larger the deficit, the greater the muscle growth - claiming it's right because the authors are cited, published and presumably experts, and we're all just idiots who base things on old science and real life.

I just find it amusing that you are so obviously trying to bait me after you accused me of doing the same in the other thread.

That is in fact exactly what this looks like to me, when you did actually accuse him of this very thing in one of the other threads.

Bear in mind, I actually agree with you, A2F, on the greater significance of anecdote and real experience etc., and that the downregulation is overplayed by studies relying on weak evidence, but this does come across as strangely vindictive.

[air2fakie]

That is in fact exactly what this looks like to me, when you did actually accuse him of this very thing in one of the other threads.

Bear in mind, I actually agree with you, A2F, on the greater significance of anecdote and real experience etc., and that the downregulation is overplayed by studies relying on weak evidence, but this does come across as strangely vindictive.

See my reply above to him, and no offense taken - you are certainly entitled to your own opinion.

[paulinkansas]

See my reply above to him, and no offense taken - you are certainly entitled to your own opinion.

I'd like to conduct an experiment. Put the 2 of you on a boat and go out in a lake to observe some signal flares. The boat will be rigged to start sinking in the middle of the lake and there would only be 1 life jacket.

[desslok]

I'd like to conduct an experiment. Put the 2 of you on a boat and go out in a lake to observe some signal flares. The boat will be rigged to start sinking in the middle of the lake and there would only be 1 life jacket.

Well, I know what I would use the flare gun for in that situation