Exercise, metabolism, and weight: New research from The Biggest Loser (2022) | Hacker News Reader

Exercise, metabolism, and weight: New research from The Biggest Loser (2022)

health.harvard.edu

38 pointspaulpauper52 comments

Just don't try to lose weight primarily through increasing activity. Activity is great for other reasons, but the human body is just too damn efficient and it would consume too much time. Caloric deficit is the best primary way.

The '5kg in 50 days' Diet! (2017)

https://youtu.be/mTABw0EyIWY

Caloric deficit is definitely true. The hard part is the implementation.

For example, I was supposed to meal prep ingredient for taco for this week so that I can have lunch, but I procrastinated and instead had noodle and ate out for a family occasion.

It used to be worse. For example, I had an expensive addiction to all you can eat hotpot.

Amen. I've tried more-or-less starving myself just by not having any food in the house other than healthy food ingredients that require significant time and attention to cook. I also went for 3 weeks without eating once, other than drinking 0 calorie hydration beverages, multivitamin, and fish oil to keep the gallbladder moving. My current strategy involves avoidance of food whenever possible.

I did the same. One afternoon I cleaned out the fridge. Food that was still 'good'. All gone. Never bought it again even though I was highly tempted at times and caved once. I knew I was wasting money by throwing away perfectly good but unhealthy food, but it was hurting my goals.

Self-control fluctuates with tiredness level and mood. You want to build systems to protect yourself when those things dip and you're not thinking properly, by adding some artificial friction.

Interesting. How long until you get over the hard part? I did meal replacement for a while (ALL meals replaced by essentially Soylent) but I just dreamt of food whenever I went to bed - which was super weird because I never dream!

For near total caloric restriction, the hump is ~3-4 days. The downside with this method is causes lose of muscle mass. It's not a safe or sustainable weight loss method in most cases.

I’m fine with losing muscle, but not being sustainable is a downer :(

I knew I'd have to feel full once in a while, so my rule was, only foods with 1 kcal or less per gram. This pretty much meant sauerkraut, pickles, raw veggies. Lemon water. Long walks.

Two weeks of this worked great.

Absolutely. Unless you do some very vigorous exercise for many hours per week it’s not going to make much of a dent. I remember jogging for an hour (I’m out of shape) and it was very difficult - I felt like getting a pizza afterwards as a reward. That would have been something like -500 calories from the jog, +2000 from the whole pizza == +1500 net.

After many years of doing it wrong - now I go with low calorie and high protein meals until dinner. ~150 calories for breakfast for example and no snacking. Once I got used to being hungry most of the day, weight loss actually became realistic.

it is even worse than that. the energy constrained model suggests it is impossible to ever work off a pizza. you just simply burn fewer calories later to negate exercise, such as lowed BMR or less NEAT. As you lose weight, your constraint is lowered and any calories above it will produce weight gain regardless of exercise.

The constraint throws off all the calorie math in regard to exercise. You find that no amount of exercise helps at producing lasting weight loss even if the meter/app says you burned 700 or whatever, which is .2 lbs. If you do this for 10 days you should lose 2 pounds of fat , keeping diet constant, but you don't. Either you lose less or just water.

If only we could find some way to harness the power of these thermodynamics-violating pizzas.

I don't think your basal metabolic rate goes down to zero as you increase exercise. There's probably at some point in which your daily total expenditure must increase, but it's unsustainable.

I find it very hard understand your paragraphs.

> (when i eat a pizza) i simply burn fewer calories later to negate exercise, such as lowered BMR/NEAT. as i lose weight my constraint is lowered. (constraint of what?) and any calories above it (above what?) will produce weight gain regardless of exercise.

what does this have to do with pizza? eating pizza negates exercise through lower BMR/NEAT: umm are you sure it's negating exercise itself? so michael phellps cannot possibly burn off a pizza? it's physically impossible?

felt compelled to comment cuz while i understand the terminology and know about this subject, i think its the particular form of writing that's just very hard to understand. thought you should know.

edit: i think you're saying you can't out work a bad diet. i usually hear it from the opposite pov: if you fast your body will compensate through lowered BMR/NEAT and so it's diminishing returns. surprised to hear your point seems to be it's physically impossible to burn off a pizza because a pizza will negate (seemingly any and all attempts at) exercise. ???

Obviously this isn't completely correct, because elite athletes work to eat 6000 calories/day and manage to "burn it off."

That said, it seems clear that exercise does not help most people lose weight; adding a small amount as you're losing weight may be a way to retain more muscle mass and improve health in other ways, though.

Exercise helps people to lose weight. Just go to a local group bike ride. Then first observe average BMI there and then talk to people and you will find out a lot of them started fat. The problem is that people delude themselves about calories - both burnt and eaten. For example riding a bike at somewhat brisk but sustainable (for a healthy average man) pace may burn 500kcal per hour (that would be around 140W). Similarly running or walking for 7km as 70kg person burns around 500kcal. You do it 7 days a week and you still can't really eat more than your baseline if you want to lose weight. We can argue if 7 hours a week is a lot of exercise or not but most people would feel they exercise a lot and use that as justification to eat more.

The problem is that we are so sedentary that a very mild volume of exercise like 7 hours a week (let alone things like going to the gym 4 days a week) is seen as "very active lifestyle" and used as license to eat a lot.

Unfortunately you're still sedentary if you do that and sit at the desk, drive a car or lie on a sofa for the rest of the day.

It's not like adding more exercise is bad. It's the fact people are sedentary, drive everywhere that it's not feasible for them to get to activity level to really make a dent. Imagine you have to walk to your office for 30 minutes every day (and then back) then walk to a store to buy food. Then do some sports on top of that and suddenly the amount of food you can eat changes drastically.

Unfortunately it's very hard to do in today's world. We even started SUV'ing children to school instead of letting them walk. No wonder almost everyone is getting fat and complains that "no amount of exercise makes a difference".

When I look at photos of my parents in their 20s I struggle to see any fat people. Almost no one had a car back then (in my country) and that needed to walk a lot just to get to school/job, buy food, get anything done around the town (no online forms back then). People usually attribute it to food availability but when I try to estimate how much they needed to walk every day I see a completely different picture.

> Exercise helps people to lose weight.

Exercise has been extensively studied in relation to weight loss, and has been found to be of limited effectiveness. Many studies found no effect, and meta-analyses found modest effect sizes.

Your anecdotes don't change my mind. The problem seems to be, exercise uses up willpower and makes you want to eat more, and only in very indirect ways (improving BMR, etc) really helps.

Of course, exercise improves a bazillion other things: cardiovascular health, blood pressure, insulin resistance, etc, etc, etc.

"Uses up willpower," I thought, was also studied and found to be lacking as a thing?

I think it is fair that "exercise" in the form of specific activity with the sole purpose of doing the activity is likely much harder to get results from than folks admit. I think it is also fair that getting more active, period, is more effective than people will admit. You don't have to have a gym membership to keep from getting over weight. You do have to be active.

That sounds idiotic. I'm on a very clear downtrend in weight and on days where I burn more calories I eat more to avoid going into too high a deficit.

(cycling workouts with power meter or on Zwift, accurate calorie counts)

I think the 'exercise isn't the key to weight loss' meme has been overplayed a little, I understand why but it's a take that lacks nuance.

To be sure: dietary control is the cornerstone of weight management. It ultimately comes down to CICO as the most impactful lever you can pull, and not putting stuff in your pie hole is the simplest way to pull it.

Your example of rewarding yourself with a pizza every time you go jogging though is contrived though. I felt that way when I started exercising, and I often did eat a lot after a workout, but eventually (6-12 months) exercising became a more comfortable and routine thing for me, and that bad habit disappeared.

Now I just get a nice 600 calorie deficit every time I go to the gym, and basically eat normally afterwards. The psychological need to reward myself is gone, it's just what I do, the endorphins and the physical improvements to my body are reward enough.

Trained athletes almost always have some sense of what both their CI and their CO is and they have developed the discipline to regulate both. If someone is 50 lbs overweight yeah 90% of the work for them in the beginning will probably be bringing CI down, they are going to be way above maintenance and way out of shape so incapable of maintaining a highly energetic exercise anyway.

But once you get over that initial hump you want to start incorporating light exercise as quickly as is comfortably possible, and dial up the intensity (as well as calorie burn) as your body adapts. Moving the needle on CO is slower and harder than moving it on CI but that doesn't mean you shouldn't bother at all.

There are 2 things that (for me at least) make exercise a core component of weight control:

1) When I lose abdominal tone, I can eat way more food before my satiety signals start firing. I screwed myself early in life by hoovering up as much of every meal as I could until I was physically uncomfortable, and that was my signal to stop eating. When I have good core tone, it's physically harder to distend my gut to pack more food in (I'm 5'6", so the smaller intestinal cavity may have a greater impact for my tiny ass).

2) The more muscle mass I'm carrying, in combination with better cardio capabilities, the greater caloric burn I can effect in the same amount of time, and the greater duration of energy output I can sustain.

My current exercise regime is a mix of kettlebells and heavy mace for strength training, and skating in the mini ramp in my backyard. 20 minutes of continuous moving of a kettlebell or heavy mace dynamically is an excellent conditioning routine on its own, and combine that with another 45 minutes of rock-to-fakie, tail stall, fakie-rock, 50-50s, 180s, backside disasters, and of course kickflips in the mini ramp all add up to a ridiculous caloric load and demand that the whole body be firing coherently at the same time.

I strongly recommend transition skateboarding for cardio, but I don't think many people are physically capable of it (although I only picked it up in my early thirties, so it's not necessary to have been doing it your whole life to get good mileage out of the sport later in life).

How do you go to work and think and function under a calorie deficit? Brains need calories and mine feels crippled without, like I am forced to choose between diet and productivity.

Start slow. First eat what you normally would to feel full, and merely measure it. Use a spreadsheet and the nutrition labels to see how many calories you're getting as well as macro %s. Leave nothing out!

First, start with obvious cuts: alcohol and candy/desserts. You don't need beer or ice cream and you will function better without them.

Then, cut 100 calories a week. Cut from fat and carbs, make sure to keep your protein and fiber up.

For me it’s best to eat filling whole foods that are inherently lower calorie - potato, rice, beans etc.

If you’re stuffed it won’t feel like calorie restriction.

Your brain needs glucose, not calories to function. Yes, we can get glucose from the calories we eat, but that's not the only way. Thanks to insulin, extra glucose can be stored in the liver and muscle tissues as glycogen. When those stores are full, it gets converted to fat and stored in your adipose tissue. This is lipogenesis.

When you're in a deficit, your body keeps blood glucose levels stable (and your ability to think and work constant) by tapping into glycogen stores from the liver. When your liver is out of glycogen, the body can convert glycerol, a component of fat molecules stored in your adipose tissue, into glucose through a process called gluconeogenesis.

While this process works, it's not always comfortable. However you can become more adapted to it and get to the point where your comfortable doing light exercise and heavy thinking in a fasted state.

Activity might not be a directly efficient way to lose weight, but (imo) increased activity leads to increased willpower to make healthy eating choices.

Inactivity (not our human default) comes with such a host of health issues, that even if activity had no bearing on weight, it would still be a no brainer to do it.

I find this kind of attitude frustrating because it likely discourages people from exercising, when they could benefit a great deal from doing both exercise and caloric restriction.

Exercise is so connected to everything else in life, like mental health and (per the article) metabolism, that the benefits to be reaped from even just walking a few thousand extra steps a day might easily make the difference between sticking to a caloric deficit or exceeding it.

By bogging down the concept of weightloss with an exercise requirement, you lose a lot of people who would otherwise be willing to diet to lose weight. Is exercise good for you? Yes, very. But you can lose weight without it.

>By bogging down the concept of weightloss with an exercise requirement

Conceptually weightloss for genpop is really get skinnier to fit into things. Body recomposition with more muscle and less fat can get you there faster and more muscle makes long terms maintaining higher weight at same waist size easier. In my experience the people who lost weight and kept it are the ones who got more muscular or have exercise goals that regulates their caloric intake. People who just diet tend to yoyo.

This feels to me like saying "hey, you don't need to buy a fire extinguisher to keep your house safe from bushfires, the primary way of protecting it is clearing vegetation away from the walls." While technically true, it presents the two methods as if they were in opposition to each other, when they are in fact complimentary. You can do both! If you absolutely have to prioritise one, then I guess you could pick one, but why bother?

It also assumes you'll "lose" people if you even mention exercising in a positive way unless someone comes along to tell them how pointless exercising is. I think the exact opposite is true: people get burnt out on weight loss because they aren't able to make it stick, and the solution is to incorporate exercise as well as educate them about concepts like losing your weight in stages then stabilising before metabolic adaptation hits, how your BMR needs to be recalculated as the weight comes off, water retention and weight loss plateaus, calorie tracking, satiation, and everything else that's been learnt through trial and error over the years.

> You can do both! If you absolutely have to prioritise one, then I guess you could pick one, but why bother?

You should ask someone who is really heavy how excited they are at the prospect of exercising, or permanently altering their lifestyle to frequently include something they don't actually enjoy doing. When faced with the choices "be fat" or "exercise regularly and make good dietary choices to lose and keep weight off" most people choose "be fat". I know for me, I managed to lose and keep off weight through diet and exercise, but most forms of exercise are still a chore. Actually, it was easy to exercise at first because I was enthusiastic about my goals and it felt important for weightloss. But as time has gone on and I've kept the weight off (still exercising), I'm much less enthusiastic. If I woke up suddenly 80 pounds heavier again, I don't know that I'd be able to bring myself to bring it back down. Especially if you told me that exercise was an essential component.

> I think the exact opposite is true: people get burnt out on weight loss because they aren't able to make it stick

I think they get burnt out because it requires a lot of discipline to control your diet, and cutting back makes you really tired and hungry. It doesn't stick because their body still lies to them about how much they need to eat, and it's exhausting to fight your body and its lies.

Ultimately, I think people correctly self-asses their interest level and motivation in maintaining a lifestyle that includes deliberate exercise. Many of the people in my life are thin and completely sedentary, and they've never battled with their diet or weightloss. I'm sure you know some people like that too, and I imagine people who want to lose weight want their lives to be like that. So, like I said, assuming exercise is not actually essential, I think the cultural emphasis on exercise does people trying to lose weight a disservice. It almost feels like wellness gatekeeping instead of actual advice.

I don't know one way or another what the numbers show about diet + exercise vs just diet say, but I'm also not sure whether I'd be convinced by statistics that show exercise is a key component to weight loss. People that lose and keep weight off only manage to do so if they are serious about it, and because there is a heavy cultural emphasis on exercise as a part of weightloss, people who are serious will also exercise to lose weight, confounding the correlation between exercise and weight loss.

> When faced with the choices "be fat" or "exercise regularly and make good dietary choices to lose and keep weight off" most people choose "be fat".

I think this is where education comes in, because when I was overweight I used to assume exercise had to be painful to be useful, and it really doesn't. Literally anything other than being 100% sedentary counts as meaningful exercise. It's okay to walk slowly with breaks, run slowly with breaks, walk in a pool where your weight is less of a factor, or whatever helps you. It's perfectly fine to exercise at a volume and intensity where you don't feel any pain at all, and "no pain no gain" is a disastrous lie.

As you note, it's hard to make that kind of change twice. I think we do a disservice by discouraging people from exercising, rather than presenting it as an optional but beneficial extra.

> Many of the people in my life are thin and completely sedentary, and they've never battled with their diet or weightloss. I'm sure you know some people like that too

My (at the time new) boss once said "I bet you don't need to worry about this stuff [diet and exercise]" at a time when I was still eating 3000kJ under my TDEE, which was quite funny. But yes, I agree there really are some people who don't need to exercise to be skinny.

The biggest problem I have is with hiding information from people. I agree that exercise isn't necessary or sufficient for weight loss, but I think on the margins exercise does help a considerable number of people succeed who would otherwise fail. That's why I don't like how most weight-related articles that end up on HN have something negative about exercise at the top of the comments.

As a contrary take, start doing weights. Go for walks. Not short ones. Adjust eating, but largely do so to give yourself more time for the activity. If it motivates you, jog or run. Bike, if you can and that motivates you.

What never worked for me, was just changing diet. No matter what the food, I can eat a lot of it. Unreasonably so. After a run of most any length, eating is just not something I want to do. Same for a long bike ride.

So, yeah, don't expect that exercise can lead to weight loss on its own. But also don't be surprised if you can't eat the same while doing exercise.

Of course, I think that is a related trap. High level athletes have a lot of calories they need. A lot of energy bars and such are necessary for long hikes, but complete overkill for walks. So, odds are you should avoid athletic food until you are an athlete...

> One contestant . . . had to consume an 800-calorie-per-day diet to maintain his weight.

This is wrong. The linked source says he “now has to eat 800 calories a day less than a typical man his size.” That’s very different.

So many thoughts and questions about this.

That's INSANE that 6 years later the bodies metabolism had not adjusted back!!? Hard to believe!!

Is there a decent sample size study for this or we going on one guy?

Maybe this person has some sort of syndrome?

If this is normal for the human race as a whole...is metabolic readjustment a spectrum like many things in biology? Like will some recover their original pre-fat metabolism after a period of time?

Are there medicines or areas of research into how to trigger this metabolism?

Are there foods and/or exercise that can build a metabolism back.

How does gastric bypass seem to work so well? Does it basically just reduce the distance of your digestive tract so that you absorb less calories which matches up to your new fat metabolism?

Ozympic seems to be a miracle drug in that it curbs the appetite so people can maintain this new low calorie diet.

> That's INSANE that 6 years later the bodies metabolism had not adjusted back!!? Hard to believe!

The paper argues it’s because they continued to have high levels of physical activity, which kept their resting metabolic rate low.

The ones with the highest metabolic adaptations were the ones who kept the most weight off, and were also the most physically active.

It can be surprising for folks that athletes have a lower resting heart rate than others do. I had thought it was greater efficiency in blood to muscle delivery, but I don't know why I thought that.

What is it then?

I don't know. Haven't read up on it.

Your heart literally gets bigger! Your stroke volume goes up, and you probably have more blood plasma, too. This aids in fueling muscles.

Though, if you Google heart hypertrophy, you'll find a bunch of scary things, because your heart can also get bigger in a bad way rather than a good way.

I'd guess there is also some efficiency in muscle tissue taking in oxygen over fat tissue? Also a bit better lungs, for runners and such? Though, I also don't know the relationship between lung efficiency and heart rate.

If you have links on any of this, it feels like it would be a very fascinating read.

This article links to this paper: https://onlinelibrary.wiley.com/doi/epdf/10.1002/oby.23308

It’s short and interesting, but the most interesting tidbit in there for me was that physically active hunter-gatherers have roughly the same daily energy expenditure as sedentary westerners. I always thought they’d have to eat huge amounts of food to fuel their activity, but that doesn’t seem to be the case. [https://pubmed.ncbi.nlm.nih.gov/22848382/]

So it seems like fast metabolism is one of those things that once you lose it you never really gain it back? Makes sense. For many, Ozempic may truly be the only viable path to healthy weight.

Going for 0.1 lb weight lost per week [1].

I started too high the first week, and now--a month in--getting a bit closer to a lose threshold.

Probably will adjust as things go. Not a lot to go on from a comment, but it seems doable.

[1] https://news.ycombinator.com/item?id=39200900

I fasted for a while (40 days) and definitely noticed a slowdown in basal metabolic rate towards the end. Initially I was around 2,600 calories but towards the end dropped to 1,700. Engaging in intense physical activity after ending my fast got me back up to 2,300 calories per day (rowing and CrossFit).

How much lighter were you at the end of your fast? It's expected a lighter body needs fewer calories to maintain.

Once you arrive at:

"and achieved a weight of 191 pounds, yet six years later, after regaining 100 pounds of that lost weight, had to consume an 800-calorie-per-day diet to maintain his weight."

You should just take a step back and look at your assumption. The contestant either wasn't able to count calories, was in medically induced coma or more likely was just deluding themselves about their calorie intake and/or lying about it.

"Metabolism slowing down" is such a nonsense term as well. Like how does it matter if your body gets slower at processing food? Maybe the body becomes a bit more efficient but that's about it. It's a good thing. It won't magically start producing energy from the sun though.

Like if you ever were around competitive athletes who care about their diet you would instantly see how nonsensical the thesis is. People struggle to eat enough to not lose weight. They eat as much as the body can process during activity (currently 90/120g of carbs per hour is a new normal at high level) and then eat a lot after to replenish their glycogen and lost fat. They would kill for "metabolism slowing down" allowing you to function on 800 kcal per day but no such thing was ever observed. We know quite well how much the body burns during activity. It's normal to burn 500-1000kcal per hour (or more at pro level) on a bike or running and you need to eat enough to cover that if you want to sustain your training volume.

Harvard publishing "people are clueless about their calorie intake but let's assume they aren't and reason from there" kind of "research " isn't good for their credibility.

It's an error, it shouldn't say 800 a day but 800 less than normal a day.

I doubt it's an error but let's assume it is. When I look at an online calculator for fat loss which uses some standard formulas for BMR (google fatcalc) I see that losing 62.5kg (91 pounds) means your "calories to maintain" are 1000kcal lower than at your starting weight.

It takes less calories to maintain a lighter body. Nothing surprising here. Metabolism didn't "slow down".

medically induced weight loss is really damn hard. vastly more drugs produce weight gain as a side effect compared to weight loss, and the few that do tend to be really dangerous or addictive. It took 90 years after the discovery of insulin, and ushering in the field of endocrinology, to develop Ozempic--the first in a class of non-stimulant and (mostly) safe weight loss drugs that work for a general population and produces substantial weight loss for most ppl who take it.

>after [reaching 291 lbs], had to consume an 800-calorie-per-day diet to maintain his weight. >A more recent study aims to explain and interpret the findings The lengths highly educated individuals go to to explain away obvious fibs. A 300lb person only eats one small meal a day and doesn't lose weight? Come on!

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