Calorie restriction in humans builds strong muscle and stimulates healthy aging | Hacker News Reader

Calorie restriction in humans builds strong muscle and stimulates healthy aging

nih.gov

110 pointsrstocker9959 comments

I did a bit of a double-take at the headline because it seems to imply that one can grow stronger while calorie-restricted, which is contrary to common practice around strength development - caloric surplus is generally understood to be necessary for muscle growth.

I've only read the abstract, but the title as I interpreted it seems misleading:

> One study showed that individuals on calorie restriction lost muscle mass and an average of 20 pounds of weight over the first year and maintained their weight for the second year. However, despite losing muscle mass, calorie restriction participants did not lose muscle strength, indicating calorie restriction improved the amount of force generated by each unit of muscle mass, called muscle specific force.

So even if force per unit increased, overall mass decreased and total strength was unchanged. I guess the title is technically correct but the implication is off. This might be better phrased as "calorie restriction in humans doesn't incur as much muscle/strength loss as previously thought", which is still an interesting result.

Increased power over weight ratio does count as "increased strength" IMO. You will run and bike much faster for one thing.

Sure, but for how long?

Potentially very long. If you look at the top endurance runners (e.g. Killian Jornet) they're not particularly muscular. In this sport efficiency rules over power.

Might not wrestle better in open weight class, chop as much wood or shovel as much snow or dirt, though ?

Wrestling seems like exactly the wrong thing to cite here, since it's generally not done in openweight, and if you're wrestling in traditional weight classes then what's described here is hugely beneficial - you can drop a weight class but not lose strength.

> you can drop a weight class but not lose strength.

Exactly. This aligns to strategic weight cutting. Once you go up and then go back down, you feel stronger than you were for about as long as you continue regular training.

Also your opponent would have an advantage of you being lighter, which affects the results

Except both you and your opponent would be using tricks to be lighter (e.g. not drinking at least 1 day before the weighing)

Normally in weight classed sports, people cut and dehydrate etc so that they are just inside the weight class they want to be in.

In other words, if they didn't cut they wouldn't be meeting that opponent at all because they would be in a different weight class.

those activities are a bit useless nowadays compared to cycling/walking/running

> which is contrary to common practice around strength development

This belief is already changing in bodybuilding and strength circles. Surprisingly, the fitness influencers on tiktok are leading the charge in changing minds about this.

Interesting - guess that hasn't percolated through to my traditional powerlifting-ish circles yet. I'd love to read/watch anything on this you've found useful.

Idk the bro science i always heard, for at least 10 to 15 years, suggests that strength is alot of stuff like neurons firing. You can take time off from lifting and get back to it pretty quick. Size from body building is mostly targeting hypertrophy, breaking down muscle and have then regrow to be larger. Strength and size would normally correlate but couldn't get someone's strength just from their size.

Oh yeah, no doubt about that. I've observed the same picking back up after injuries, and some version of this whole thing is ultimately what's backing the concept of cutting. Definitely not trying to say that mass equals power or anything. I'm just trying to zero in on the gains while not at surplus thing, because ime I can lift all day but don't gain (as measured by increasing lift capacity) jack shit unless I also eat big. I don't particularly love bulking and cutting, though, so I was kinda hoping there was a trick I was missing.

That Ukrainian guy on tiktok who only weighs around 80kg but can deadlift over 270kg.

Anatoly. Very fun channel on YouTube.

"This belief is already changing in bodybuilding and strength circles."

This is a mistake and one that can be extrapolated to the much larger world.

Real world growth implies building in excess of the target and then trimming the leftover.

I don't care if you're planning a battle charge or setting your family finances or going for massive gains in your delts: exact allocation of resources is doomed to fail.

In fact: the "bro science" of bulking up in a training phase and then "cutting" to a competition weight, etc., is revealing a deeper truth about the world.

I'm probably leaving way too much information on myself on this website, but Anne Debouté, a french kayakist (won France Championship, top 8 in a world cup) told me she ate a lot after the competion season, but 5 month later (in the 90s), she cut her calory intake and lost up to 15 kg. Her trainer was skeptical, but she did it every year and told me she really felt relatively stronger despite being less muscular, so i guess she was right in the end, and her trainer wrong. I'll bookmark this.

I was part of 9 month University weight loss study.

I had a Dexa scan before and after. As well as various other ultrasounds, physical tests and blood tests.

I lost weight and gained muscle according to the Dexa scan!

No other changes to my general exercise. I wasn’t weight training or doing cardio. Just walking and day to day stuff.

That strength (which has to be defined via a mostly arbitrary set of tests) can increase while body mass or even muscle mass decreases is not controversial, anyone who starts strength training while losing weight can attest to that. There's more to force output in a specific context than contractile tissue mass.

Increasing muscle mass while losing body mass is a very different question though.

This is super interesting though! It would defeat the myth "don't try to lose weight while weight lifting".

Any calorie based study when it's self reported should be highly suspect of being false.

One of my favorite studies, an oft-replicated and cited study, tracks several hundred people who claimed to be "diet resistant". Using a technique invloving "doubly-lableled water" they were able to determine that every single person in the study who claimed to be diet resistant was overreporting their exercise and underreporting their calorie intake:

https://www.nejm.org/doi/full/10.1056/nejm199212313272701

Of course, this was a study of obese people. If you're doing a study on healty-weight people who are trying to build muscle, you may get far fewer people who will lie.

Is it supposed to be surprising that someone having weight issues would have issues reliably tracking the impacts of actions that would lead to their weight?

Have any similar "favorite studies" on hand about alcoholics who underreport alcohol use and overreport abstaining? Punching down is a favorite pastime of mine too btw :)

> Have any similar "favorite studies" on hand about alcoholics who underreport alcohol use and overreport abstaining?

Thank you for your genuine concern! Unfortunately, I don't. I track weight loss studies because I had struggled with weight gain and obesity. I am fortunate to have never had a problem with alcohol. I hope you can find the help you need.

It's not punching down.

It comes with frustration that these garbage studies mislead people who have been struggling with their weight by discouraging them from internalizing the simple facts that lead to effective and sustainable weight loss/maintenance/manipulation.

You see them cited all the time by people who've grabbed onto the next diet fad in hopes of achieving what bodybuilders and athletes who compete in weight classes have known for decades.

Participants also lost weight and muscle mass in this study. 12% calorie restriction and 10% weight loss maintained over 2 years (avg weight reduction of 7.5 kg vs 0.1 kg weight increase in control group), of which 71% was fat loss.

> They found that during a two-year span, the goal for participants was to reduce their daily caloric intake by 25%, but the highest the group was able to reach was a 12% reduction

This feels like something the royal we should be talking about as well.

It’s clearly really difficult to restrict calories/eat less in the US. It’s unclear if this is a US only phenomenon or not but I wouldn’t be surprised if it were.

It's not hard to restrict calories in the US if that's what you've always done, but if you grew up eating a lot, it's hard to stop eating a lot. Doesn't matter where you are in the world, it's just hard to change your lifestyle long-term.

> It’s clearly really difficult to restrict calories/eat less in the US

Just came back from a 3 weeks trip to the US. I found it easy to control my calorie intake by just skipping a meal or two and avoiding sodas and sweets. It was much harder to eat something reasonably healthy while being on the move though. I'd be curious to check my cholesterol level before and after the trip.

Little anecdote… my friends and I are mostly from Europe and travel a lot and eat food from all over the world… we are mostly not fat. So the only country where we gain weight without doing anything else are the USA. It’s like magic. And yes it’s the food and you people don’t walk anywhere. Not even a block. Still love your culture.

Then here in Australia I'm seeing a massive increase in people using electric scooters rather than walking

12% reduction of what? The basal metabolism? Were the people overeating before? How many calories on average?

Read the article.

I never get this "calorie restriction" term. What does it mean? I have a BMI of 20. Should I reduce my intake by 12%? When do I stop reducing?

I want to live longer. I would also like to build some more muscle, ideally to a BMI of 22. What if I gain 10lbs of muscle then restrict?

Read Roy Walford out of UCLA on the CRON diet

It just means eating 12% fewer calories than your baseline to maintain your current weight. So if you eat 2,500 calories per day to keep your weight and activity levels, bump it down to 2,200 and keep it there. I have heard that it is possible to build muscle while "cutting" (calorie restricting) but it's going to be much slower and probably more uncomfortable. Note that this study was a 12% restriction maintained for 2 years. The metabolic and inflammatory benefits persist long after the calorie restriction period in animal models, and this study seems to show the same genetic pathways are getting upregulated and downregulated in humans as we have seen in the animals that benefit from longer lifespan after calorie restricting.

When you put on 10 lbs of muscle, presumably your baseline will be slightly higher than it was prior to that (extra muscle requires extra calories to maintain), but still less than what it took to put that muscle on quickly and efficiently. I have no clue how much you should expect that difference to be, I'm sure many a bro scientist has opinions on it, some of which may be reasonable. Bulking and cutting is a classic technique in bodybuilding, however, typical cuts go on for a few months at most as opposed to 2 years.

One major takeaway from this study is that on average, you will be just as strong as when you started calorie restricting even though you will have lost muscle mass. It is theorized that your muscles will have become more efficient, so if you put on more muscle after a long period of calorie restriction you will be considerably stronger than if you had skipped the calorie restriction and just added the muscle. Food for thought.

"It compared outcomes in a group assigned a target of 25% CR (i.e., a 25% reduction in energy intake below baseline levels) with outcomes in an ad libitum diet control group. "

and

"... CALERIE TM participant requirements included:

    Absence of significant health problems, including diabetes, cancer, heart  and liver disease, and AIDS 
    Absence of medication use except oral contraceptives 
    Age from 20 to 50 (inclusive) for men and ages 20-47 (inclusive) for women
    Body mass index (BMI) of 22-27.9 (lean to slightly overweight) 
    No recent substantial weight loss
    No history of eating disorders, behavioral, or psychiatric problems 
    Use by women of an acceptable form of contraception throughout the study"

Source - https://calerie.duke.edu/background

If people lost 20 lbs in the first year of a 12% calorie restricted diet then that means that this study took place among people who were already obese (which seems extremely relevant). Anyone who is in good shape and not 6'8 is in no position to lose 20 lbs without serious risks to their health, aside from vastly decreased muscle strength. It is interesting, but not very surprising, that obese people with atrophied muscles don't lose "strength" by cutting calories and losing some muscle mass, which is very low to begin with.

I'm not sure of your math. I weigh 180 at 5'9". That's well under obese. If I lost 20 pounds, I'd be just under the midline of healthy.

Yeah they're pretty far off.

Does any one find hard to eat a lot of protein (150g) in a 8 hour feeding window? I hate to live off of protein shacks.

Roughly 40g/meal for me, plus one 30g snack (usually a shake).

Do you really need that much protein though?

That’s quite a contentious question, there aren’t that many good studies, and they are difficult to do well

It’s really not: https://examine.com/guides/protein-intake/. There is tons of quality research quoted on examine.com, and the results around protein are very conclusive. The short answer is that the recommendations are for much higher protein intake than most people think, and than most standard food will give you.

That site you linked says people with active lifestyles can need as much as 3g/kg, if you weigh 80kg that's 240g of protein a day.

Their recommendations are always a range, and for athletes the recommended range generally tops out at 2g/kg. But the recommendation can be higher for people with very strict body composition requirements, especially when trying to lose the last bit of fat when you are already very lean (e.g. bodybuilders before a show, action movie actors etc). But the range for most people is pretty wide, and it’s not a requirement, it’s just that you’ll probably get better results when gaining or losing weight if you err higher.

But yeah, even the minimum is a lot, and it’s hard to achieve without building all your meals around protein.

Need for life? Maybe not. But for sports performance, 1.4 to 1.6 grams per kg of bodyweight is about where the ROI tapers off for most people so far as i know. More probably only if one is very lean or anabolically reistant.

I do 4 meals at 40g each. Only one of those meals has a single scoop of whey protein (I add it to my pre-workout oats). Though all the meals usually revolve around some high protein source like cottage cheese, skyr, eggs and of course chicken breast. YouTube is full of high protein recipes (look for bodybuilding "full day of eating" videos and the like). Some channels just produce a ton of videos with anabolic recipes (jclarkefitness, felu and pretty much every major fitness influencer).

I'm sure this won't be enjoyable to many people, and only works well for certain meals, but my secret weapon is gelatin powder. Mix with water until paste forms in your bowl then put steaming hot food on top and it will turn into a kind of 'creamy' sauce-like consistency. Nice mouth feel without too much flavor.

Oh, and learning to cook meat/protein so it is tender, browned, flavorful, and seasoned properly. It also seems like acid is way under-utilized in a lot of lazy / American style cooking. Helps a lot with palatability and digestion to use lime juice, rice vinegar, and other acidic ingredients during the cooking process.

Eat more veggies, too. They are full of digestive enzymes, but most veggies don't add too many calories.

Why 8hr? For the entire day eat 5 times and 200 plus grams is very doable. I only have one scoop of whey, and sometimes a bar, but everything else is lean Protein or carbs and fat that also have protein (oats, pb, yogurt)

Intermittent fasting. I don't know if there are any real documented benefits but anecdotally fasting is pretty nice. I often feel very energized and clear headed while fasting.

If you want 150 grams of pure protein that's about 500g of chicken meat. Other things have protein as well so you could probably bump it down to 400 and have some other stuff like rice and veggies on the side.

Thats a pretty big meal but if you split it in two and have 8 hours between them it's really not that much. Doesnt seem like it should be a problem.

I've spent years without eating any meat, and this week I ate 500g of chicken in one shot, that feels good. But I really don't need it every day, it's also not very scalable in terms of environment

I'm 60kg, 1m83, with I guess strong and endurant muscle with all the bike and manual tasks I'm doing

Whey can easily get you 50g daily with low effort.

Reply on news.ycombinator.com