Comment by Gatsky | Hacker News Reader

Comment by Gatsky | Hacker News Reader

This study was in Chinese people who were overweight and were eating a lot of carbs (~300g a day). Presumably this was largely high GI rice. IF made a modest difference. They also lost some muscle mass, as expected. The study tested a lot of different variables, apparently without adjusting for multiple hypothesis testing.

Hard to generalise these results. If you are eating a toxic diet, I guess more time without it is a good thing. A similar study in a Western population showed no effect of isocaloric IF [1]. In another study, IF with energy restriction in obese subjects was more effective than energy restriction without IF [2].

I don’t see that the data supports IF as a universal strategy. If you are obese, then these studies suggest eating less, for less hours of the day and less at night is probably beneficial. Otherwise, as far as health interventions go, exercise has a much larger magnitude of benefit than dietary interventions. It also has the major advantage of simplicity - more exercise is better for everyone everywhere at every age [3]. Contrast this with the utterly confusing state of nutrition science. And exercise also makes a difference even when you do a little bit, whereas eating a little bit better does almost nothing.

[1] https://jamanetwork.com/journals/jamainternalmedicine/fullar...

[2] https://jamanetwork.com/journals/jamainternalmedicine/articl...

[3] This is not 100% true. There are some contraindications to exercise for people with specific conditions.

EDIT: When talking about the benefits of exercise versus diet, I mean the effects on health in general (mortality, lifespan, healthspan). Exercise isn't an effective method of weight loss as others have indicated.

I have been experimenting with lifestyle TRF for 5 years before finally finding an approach that works consistently with little effort in a modestly socially acceptable way with common food sources.

Starting from 235 pounds I lost 55 pounds since April by restricting my feeding time window to 4 hours and I only exercise once every week or two.

An eating time window larger than 4 hours did not result in any meaningful long term weight loss for me. It must be 4 hours per day or shorter. 4 hours works great.

I barely made a change in my diet to eat healthier besides cutting out foods and beverages commonly known as being bad and I only drink water and coffee. I consistently begin to plateau and this process only stops with increased water intake and exercise, but mostly water intake more than 1 gallon per day.

In terms of effect size time restriction is most critical followed by eating food that isn't obviously unhealthy (e.g. anything containing added fructose), closely followed by drinking a gallon of water per day. Exercise is a distant next step but it has a big effect whenever loss plateau begins.

As I approach my weight goal I plan to expand my eating window by one hour per day per month until I plateau.

Forgive the question, but why is exercise such a distant next step for you?

You very clearly have a lot of self-discipline, and you have your shit together. For me, exercise has always been the most rewarding part of the whole deal.

Really glad that you took the time to make the effort over literal years to find what works for your body. For most people - myself included - that's what it takes.

And most people won't stick with it and see it through.

> You very clearly have a lot of self-discipline, and you have your shit together. For me, exercise has always been the most rewarding part of the whole deal.

Not OP, but answering for myself: I don’t enjoy exercising, and not doing something is far easier than doing something extra.

I have easily removed most carbs (doing Keto), and reduced my eating window to 8h. I’ve been doing this for almost 10 years. Hell, I even got an electronic desk and work standing 70% of my work day.

But exercise is extra. I can’t just do exercise while doing something else (maybe if I enjoyed audiobooks it would work better, but I’m really into reading books), so any exercise takes effort for something I don’t enjoy unlike all other changes.

I felt this way for a very long time and have made similar choices. I simply can't get myself to consistently go out on runs, or work out on gym machines. That said, out of sheer chance I discovered an enjoyment of powerlifting and swimming and I've been able to keep those up, and even look forward to doing them. Perhaps it's a matter of finding the exercise you can tolerate.

There are many forms of exercise outside of a fitness center. I know a handful of guys in their 60's and 70's who are in fantastic shape due to fencing. They can still regularly place in the top 20% of regional tournaments against guys in their teens and 20's.

"Perhaps it's a matter of finding the exercise you can tolerate."

This.

I was a bit of a free-weight gym rat in my 20s and never liked it (still don't), but have over the years find things I have/do enjoy, and that makes it easier to get stuff done. Some are very low friction to accomplish regularly (Kettlebells, ergs, trail-running/hiking...note, I hate running on treadmills or in urban environments, but will alternate running and hiking in an afternoon in the forest like a 5 year old kid exploring. It's actually a joyful event for me. YMMV). Other things happen perennially due to logistics or weather (e.g. swimming, rowing, Bikram yoga).

I've tried lots of other things in between, so there is some measure of "i need to figure out what works and what doesn't" and that in and of itself can be an unpleasant set of experiments, but...

Sure you can do exercise whilst doing something else. I get about an hour's exercise in daily whilst moving to places I need to be.

The idea that exercise needs to be an activity in its own right is somewhat toxic. It puts a big burden on beginning the activity which needs to displace something else. Even for those that manage to get an hour at the gym or whatever, it doesn't necessarily make up for the rest of a sedentary lifestyle.

reminds me of

https://m.youtube.com/watch?v=KPUlgSRn6e0

but not very easy depending on where you live

Alas, the furthest I need to go is to the store, about 800 meters away. I walk everywhere, but nothing is far.

You can also just walk around while doing something else, e.g. listening to a podcast or talking to somebody on the phone (this can even be a work meeting!)

Walking is not great exercise from a time efficiency standpoint. It's like half the caloric burn in twice the time of any dedicated exercise, be it running or swimming or weight lifting. Exercise that elevates your heart rate is simply better, from a fitness perspective or from a weight-loss perspective.

Depends on what the goal of the exercise is. For the majority of people who need to be in better health, zone 2 cardio is what they need rather than increased caloric burn. You can't look for time efficiency with zone 2 cardio - you just have to do it for enough time to build conditioning. Depending on the person, zone 2 might be running, but for most people a brisk walk is enough.

That doesn’t matter when you’re sneaking walking into activities you’d normal do sedentary. It’s not competing against dedicated exercise.

I have this goofy plastic As Seen On TV board that is bent in the middle. Whenever I’m watching TV or playing a game, I stand in it and waddle my body so that i’m doing a light core activity.

It doesn’t matter that sprinting is better exercise when I otherwise would be sitting in the couch.

Efficiency isn't the only factor. I'd say the most important factor is enjoyment. We each have a finite amount of willpower. If you're using it up on exercise you hate doing eventually you're going to hit a day where you don't have much willpower, skip the exercise and break the routine.

The most time efficient exercises I know aren't ones you can sustain for longer periods of time. I can consistently walk for hours but only run sprint intervals for a few minutes. Sure every minute of sprinting burns more than a minute of walking but if I can walk significantly longer than I can sprint it will probably lead to a higher total calorie burn.

As others have said, it's not about efficiency. Also, doing a brisk walk does elevate your heart rate (mine goes up to ~100-110 BPM). If your goal is just being healthier, and not necessarily increasing your stamina or building up muscles, than walking is great. It also doesn't fuck with your joints.

> Walking is not great exercise from a time efficiency standpoint.

Sure, but it's infinitely better than a more efficient exercise that never gets done.

As someone with a mostly daily workout habit for the past 10+ years, the trick I’ve found works best is not to exercise, but do a sport (that you enjoy). Then everything else falls into place on its own.

I used to lift. That got boring fast. Then I got into boxing. That hasn’t gotten boring ever. Eventually I started running, you know, to have more stamina in the boxing. That has lead to several marathons and a motivation to beat the magic 3-hour barrier. Now I’m back to lifting because it helps with the running and the boxing.

Running has actually turned into my me time. A socially acceptable way to be alone, outside, ignore the world, and have no responsibilities. Great time to chug through podcasts and audiobooks too.

> Great time to chug through podcasts and audiobooks too.

One of the reasons I feel liking those would be advantageous. But I have a strong dislike for them.

I specifically like podcasts in the context of running and only started listening because I got bored of music. Started audiobooks because podcasts got too short.

Can’t stand either format otherwise.

What about hiking or going on walks?

Not OP, but share similar sentiments with OP about exercise, so maybe this perspective can help. /shrug

Hiking is my jam. I love it, and it's the one area of exercise where getting my ass kicked physically feels incredibly worth it. The trouble with hiking is that I like getting out into the mountains to do it (I prefer the less-traveled hikes that really get out out, up and away from everything and everyone... solitude, baby!), and I have a couple of small kids, so I can only get around to what I consider a "quality" hike once every couple of months. That'll change as they get older, but yeah.

Walks are different; I walk my dog for about 20-30 minutes every night, but it's just not the same for me.

I hate it. I’d rather exercise (which I do, just unhappily) than walk somewhere just for the sake of walking. When going somewhere by myself, I walk at a speed that some people would call jogging, but that’s for getting to a spatial goal.

I don’t know what I did wrong but I was on a Keto type diet for over a year but I lost muscle mass and had multiple alopecia-looking hair loss spots occurring on my scalp. I looked great because I was slimmer but I fell off the keto wagon. Anyhow, I’m eating carbs again and hair is back to full health and muscles are noticeably back to prior mass. I don’t lift—-just usual busy work of activities.

Elimination diets, whether keto or anything else, put people at heightened risk of subtle micronutrient deficiencies which can cause all sorts of weird symptoms. If you're going to eat only a limited set of foods then take a detailed look at nutrition labels and make sure you're not missing something. Multivitamin pills are mostly useless for people eating normal, healthy diets but can be a convenient way to fill in the gaps for people eating restricted diets.

Keto isn't an elimination diet, it's more of a reduction diet (people choose different levels of carbs ranging from the < 10 hardcore crowd to the 30-50g crowd). You can eat a lot of veggies, certain types of fruits, meat, nuts and dairy. There's just a ton of variety available across a wide nutrient spectrum.

Any "diet", even SAD can leave one with deficiencies if you just eat pre-packaged foods. One always should look for variety in their food selection.

Not saying keto is necessary or for everyone - it's not. But it's pretty easy to not be nutrient deficient on it.

Just out of interest, did you eat a balanced diet, mainly with a lot of different vegetables? Or closer to /r/keto "egg & bacon everyday"

GP here, I gave up on keto after one year because it required eating a special diet which is difficult to prepare and store while traveling. 4 hour TRF worked for me long term.

Did you do resistance training on a regular basis while on keto? When at a deficit, your body gets rid of what it doesn't need. The goal is to tell your body it needs the muscle (and doesn't need the fat).

Edit: just read that you don't lift. That's why you lost muscle.

Doing frequent hard exercise that builds lean muscle tissue is essential to long-term metabolic health. Just not being fat is insufficient if you want to maintain a good quality of life in your later years.

You may find it unpleasant. That's fine. Learn to enjoy the suffering.

https://www.gabriellereece.com/muscle-as-the-cornerstone-of-...

https://peterattiamd.com/ama39/

This was about how despite following harsh-ish restrictions, exercise is still a problem.

The TRE approach is closer to a natural pattern, as our ancestors - generally - also had a limited window of time in which to eat [when they did]. A notable difference between ancestral and modern habits is that eating was, as a rule, a physical activity in itself [walking and overcoming obstacles in gathering or running - and overcoming obstacles - in hunting].

I also could never motivate myself to do exercise, like running or going to the gym. What I found that works for me are:

- Doing brisk walks, either when you are going somewhere, or if you don't need go somewhere, just around the block. And yes, brisk walking is also exercise =)

- VR gaming (e.g. Beat Saber gets your heart rate up alright, or if you need more, I can recommend boxing or dedicated fitness games, but the latter are again boring to me).

- Yoga at home (I can recommend Yoga with Adriene on YouTube) - going to actual Yoga classes never worked for me, but doing at home works amazingly well

- Hiking - being out in nature feels great and depending on the level of hike, this can be amazing exercise

Hello, we're very similar it turns out.

My solution to this problem was "Couch to 5K" as it told me when to walk and when to run. Just did what I was told. I did duolingo while walking and audiobooks / music while running. Decided to go to the gym every single day for 30 mins (it's very close to my house) to walk and if it was a run day just do what the app told me. I succeeded in completing the program and I'm moving on to the 5K to 10K with the same system in place. It's amazing how the body adapts with small spaced ramp ups like that.

The easy solve for this is choosing to live somewhere where activity is baked into your lifestyle. I haven't 'exercised' in the gym-going sense in years. BUT, I chose to live in a location that allows us to be a single-car HH. So I have 40m per day of 'activity' doing my daily errands on the bike on week days. And on weekends we typically do one or two walks, and once a week I have an indoor soccer. It takes no effort to do something 'extra' to do this once you realize that cars are cancer.

The method of dieting probably drives GP's energy level to the floor. He/she is probably exhausted all of the time.

Nope I have normal energy and ride my bicycle 25 miles at a time every week or two

There is no proven health or performance benefit to drinking extra water beyond your level of thirst. The goal should be to maintain proper hydration and electrolyte balance rather than drinking a certain minimum volume of water. The optimal amount will vary a lot depending on genetics, diet, activity level, and environmental conditions.

https://www.goodtogobook.com/goodtogobook.com

I lose more weight per day when I drink a minimum of 1 gallon of water. The opposite is true when I don't drink enough water because I otherwise "feel fine." Beats me as to why this is so.

I wonder if it is the feeling of satiation rather than any benefit the water is bringing for hydration.

If true it is only a minor and temporary effect because it passes right out within the hour. It seems to work on another level.

I used this technique while cutting in a previous life where I lifted frequently. I'd drink a bowl of "water soup" before bed, so that I would feel temporarily satiated and be able to fall asleep more easily. (My water soup consisted of hot water, a bit of soy sauce to add saltiness, and a bit of sesame oil for greasiness... basically I was making a minimal imitation soup stock.)

> I only exercise once every week or two

If your goal is weight loss, this is fine, but if your goal is a healthy lifestyle, this isn't enough.

> They also lost some muscle mass, as expected.

Not sure why that would be expected. Fasting leads to significantly increased levels of HGH which preserves muscle and improves body composition. [1]

Fasting yields an up to 1250% increase in HGH depending on the duration of the fast. [2]

[edit] > ...exercise has a much larger magnitude of benefit than dietary interventions...

This could not be further from the truth. Exercise is not a good way to lose weight. It has a ton of health benefits and you should do it anyways but you should not expect to lose weight from exercise alone.

Think about it, 1lb of fat loss requires a caloric deficit of 3500kcal. An average human burns like 100kcal per mile running - so 35 miles per pound of fat. Deficit. Humans are well known for compensatory eating, after all you're running 1.5 marathons, you're going to be hungry, right? Someone who needs to lose 16bs needs to run from San Francisco to LA along the entirety of the high-speed rail Phase 1 track, via Merced, Bakersfield and Palmdale.

This is bad advice and it simply does not hold up.

> Contrast this with the utterly confusing state of nutrition science.

Fasting is the simplest nutrition science there is. BMR 2000kcal? Don't eat for a day, lose 0.6lbs. Or, you know, run an entire marathon without treating yourself to any more food that day than you would have normally consumed.

[1] https://pubmed.ncbi.nlm.nih.gov/3127426/

[2] https://pubmed.ncbi.nlm.nih.gov/6758355/

Just because it boosts GH doesn't mean you build muscle. Undoubtedly, fasting has positive metabolic benefits, but building lean muscle mass isn't one of them. The studies I have seen about regular fasting and muscle mass generally show loss or at best maintenance with exercise. Generally you will be catabolising muscle when you wake up from sleeping, until consuming sufficient protein. This is why body builders eat so often, and also try to have some slow release protein before sleeping.

You are right that exercise isn't a good way to lose weight, I am not talking about that at all. By magnitude of benefit I am talking about mortality/longevity/frailty, not weight loss. That's what really matters.

The relationship between body weight and hard clinical outcomes is complicated and not monotonic (obese pre-menopausal women are less likely to get breast cancer, to provide one example). Additionally, asian people suffer from the skinny-fat phenomenon, where they are not obese but have metabolically pernicious visceral fat.

The post you are responding to does not make the claim that it builds muscle, nor does it make reference to lean muscle mass... It says "preserves" muscle (comparable to "maintenance" as you suggested).

I'm not buying it. Muscles use energy even while at rest so in the case of an emergency I'm sure the body will first remove the useless consumption of unnecessary muscle mass than to start tapping the reserves.

In what world would the body prioritize consuming "unnecessary muscle mass" (the thing you need to hunt down and kill food) over fat, which is by definition energy stored for this exact scenario?

Muscle simply doesn't consume much more energy at idle than fat does but is far more useful and far less calorie-dense. A pound of muscle burns 4-6 calories per day at idle vs a pound of fat which burns 2-3 calories. Basically the same.

>In what world would the body prioritize consuming "unnecessary muscle mass" (the thing you need to hunt down and kill food) over fat, which is by definition energy stored for this exact scenario?

I would predict that the body would consume both, in a ratio that shifts from fat towards muscle as energy supplies dwindle, in an attempt to stretch the final reserves by reducing consumption.

HGH promotes breakdown of fats [1] and inhibits the breakdown of muscle [2]. Since fasting significantly increases HGH, that would all make sense.

[1] https://pubmed.ncbi.nlm.nih.gov/11086655/

[2] https://diabetesjournals.org/diabetes/article/50/1/96/10905/...

>in a ratio that shifts from fat towards muscle as energy supplies dwindle

it's in fact the other way around. The body first reduces what is not used (unused muscles) and then energy reserves.

[citation needed]

>citation needed

common sense

Try to build some muscle and get shredded... should be very easy with your methode/logic

With respect 'common sense' is frequently wrong which is why I was asking for some study, evidence, documentation etc. Along the lines of the articles I provided.

If you just want an anecdote it certainly works for this guy [1]. And he, in turn links out to a ton of studies.

To be clear at no point did I claim that fasting would grow muscle, I don't have any data to back that up. What I said was that your body will preserve muscle when fasting because muscle is useful and fat is not. This is backed up by the articles I cited indicating significant HGH increase, and articles citing the role of HGH as inhibiting the breakdown of muscle and promoting the breakdown of fat.

Your claim requires evidence.

[1] https://leangains.com/

> Fasting is the simplest nutrition science there is. BMR 2000kcal? Don't eat for a day, lose 0.6lbs.

And there are additional benefits aside from basic weight loss. Fasting for a day every once in a while should be regular behaviour. Some religions sort of get it and there are versions of fasting in most major religions. But for basic weight loss, it's very simple. Stop eating so often, stop eating so much, stop eating garbage. Unfortunately it's not easy.

>Humans are well known for compensatory eating

True, but this applies to fasting as well as exercising (if not more so)!

At the end of the day, what matters most for fat loss is changing your habits. I don't think that "calories in / calories out" has been invalidated, so you have two sets of habits you can adjust. If it is easier for you to reduce calories in with fasting vs. portion control, then go for it.

IME it is incredibly painful to miss a meal, but not so painful to eat less calories when I do eat - particularly if I substitute high density carbs (bread, pasta, sugar) for lower density (veg, etc).

I do think that just focusing on calories out is problematic for the obese and/or long term sedentary - mainly because they are way more likely to injure themselves by not ramping up to activity very carefully...

> IME it is incredibly painful to miss a meal.

Like anything it takes practice! Day two is usually the worst but then hunger basically zeroes out and doesn't come back until ... well, ever. Apparently it returns once you run out of fat stores, but I never got that far. You get cravings once in a while, but not hunger.

> An average human burns like 100kcal per mile running

This is not true, and it’s far off the mark for those who are overweight.

> A general estimate for calories burned in one mile is approximately 100 calories per mile, says Dr. Daniel V. Vigil, an associate clinical professor of health sciences at David Geffen School of Medicine at UCLA.

But sure it varies by weight. That said, the super-overweight are also too out of shape to run anywhere close to the required distance.

[1] https://www.healthline.com/health/fitness-exercise/running-b...

An average human isn't overweight enough to make this matter. That's why it's an average.

For a morbidly obese person they burn more calories standing up and walking around the house than I do. The thing is once you're past this phase of being overweight or obese your caloric expenditure drops precipitously. When I was working out 4 days a week my body adapted such that my caloric consumption had to go from 3200 calories a day to 2500 calories a day to maintain weight.

Running is not an efficient way to burn fat. It never has been, and never will be. The reason marathon runners are so rail-thin is because they run a lot. Running preferentially burns muscle as well due to the quickness of conversion after glucose is gone. Worse yet, there's no increase in calorie burn via muscle gain and hormone stimulation. It's just a flat consumption of calories.

In summary: being overweight is an edge case and not an average. Any mildly trained person will realize a drop in overall calorie expenditure as their body adapts to exercise. This is why modern exercise science emphasizes "confusion". Otherwise you plateau (and pretty hard, usually).

> The reason marathon runners are so rail-thin is because they run a lot. Running preferentially burns muscle as well due to the quickness of conversion after glucose is gone.

I think there's some selection bias to this though. The morbidly obese tend not to be marathon runners, as well as the very muscular. Marathon running is an extreme activity that preferentially self selects certain physical attributes and conditions. This is not to say that a morbidly obese person can't take up marathon running - but they unlikely to be able to maintain it successfully while remaining so.

Original GP quote:

> Otherwise, as far as health interventions go, exercise has a much larger magnitude of benefit than dietary interventions.

Note that GP doesn’t mention weight loss, only health in general. To push further on this point, many studies came with the conclusion that exercice had more impact on health than dieting (subjects wouldn’t lose weight, but get healthier)

e.g: https://www.cell.com/iscience/fulltext/S2589-0042(21)00963-9

But exercise increases your muscle mass, which raises your basal metabolism, doesn't it? How big is that effect? Seems like it should be quite big, but I have no data and seldom see it discussed, as if it didn't matter at all.

But then why do we lose muscle mass if we don't exercise? Seems like it would be a huge maladaptation if muscles were "cheap".

Musculature alone doesn't increase basal metabolism by a lot. At least not the muscles gained from typical light exercise stuff. It's a combination of maintaining them and exercise that gets you maybe an extra 300-500 a day average.

Muscle mass also isn't lost as quickly as people claim. It varies based on person and diet. You lose some, but many can get back to their former peak in a few weeks if it has been a year or so. Even fairly muscular individuals.

> Not sure why that would be expected. Fasting leads to significantly increased levels of HGH which preserves muscle and improves body composition.

If you lose a lot of weight, that means that your muscles have to work less to move all that weight around.

I wonder if regular resistance training would've avoided the muscle loss.

Dumb question: Wouldn’t every diet show no improvement with an isocaloric control group?

I find it interesting you criticize their study methods but then assume what food they are eating (GI rice) without evidence and state that it is toxic, without evidence, and then use this info to draw conclusions.

Forgive me for being brief, Supplementary table 3 breaks down the the baseline food intake, and rice and wheat flour are the top two items.

Regarding your second query, the first line of the abstract of the article is: "Overconsumption of carbohydrate-rich food combined with adverse eating patterns contributes to the increasing incidence of metabolic syndrome (MetS) in China. "

High levels of blood glucose are toxic to most tissues, and high GI foods tend to cause glucose spikes. This is like Physiology 101 level common knowledge and not something that requires additional evidence in every little comment.

This isn't wrong, but it's pretty hyperbolic. A large helping of white rice isn't "toxic" in a meaningful way.

But as a diet, this would be glucose spikes multiple times per day, for perhaps a lifetime. That may not qualify as "toxic" I guess, in that it doesn't kill you on the first day. But it is not benign.

Rice is literally the most commonly eaten food in the world, eaten by billions of people a day.

Rice is commonly eaten mostly because it's easy to grow in wet climates, and it's a cheap source of calories. I eat rice myself, but let's not be fooled into thinking that rice and other grains are particularly healthy. Small amounts are fine, but if you get the majority of your calories from grains or consume large quantities in a single meal that cause blood glucose spikes that certainly isn't ideal from a health and fitness perspective. Everything in moderation.

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