> "So if we burn more of our energy every day on physical activity, on exercise, after a while our bodies will adjust and spend less energy on the other tasks that we sort of don't notice going on in the background," Pontzer says.
I also think this is true related to food. Your body adjusts its metabolism based on the amount of food you eat as long as it's not chronic. That's why you can have competitive eaters that can eat a weeks worth of food and not be overweight. Spikiness and variability are probably good for you. Its funny that the Bryan Johnson types who closely control every calorie in their body have such a bad reaction to any variability. I don't know if its him, but I heard someone not be able to sleep and their levels got all messed up from one sweet. And their conclusion was sweets are so bad for you, rather than you're building your body to be too fragile to shocks.
The interesting thing is when this breaks down. Obviously if you eat a weeks worth of food every day for a sustained period of time, you will start to gain weight. Or if you run 12 miles every day, you will be in such a deficit that it won't be possible to lower your metabolism enough. Outside of the extremes, I think it's a cliff, where you have to have some kind of shock for some period of time for your body to react.
The timing of when I eat changes, if I gain weight. Eating pizza after jogging? Fat on belly.
Eating as much pizza as I want, but going to bed after on empty stomach after running, or putting the running in the morning while doing about 12 to 16 hour slots of intermitted fasting? Hello, six-pack.
This is true to an extent and I'm very fond of the saying, but beyond a certain point you can indeed outrun a bad diet.
I used to spend ~4 hours a day training martial arts (kickboxing, BJJ, etc) during which time I could eat almost anything I wanted without gaining weight.
I'm sure if I had downed a cheesecake a day it would've been bad for me, but I was able to get away with a level of excess back then that I am unable to today.
So you can indeed outrun a bad diet, it just takes more running than most people want to do!
I’ve been thinking about writing a book on this topic: “No overweight person eats well”.
By very definition of a person is overweight, they got there by eating poorly, and are continuing to do so. They have eaten more energy than they use, this energy storage in fat.
The title is disappointing: it implies a causal relationship. The study was an observational study.
Indeed, you can outrun a bad diet: we all know that. The study just shows that the lack of activity isn't the main reason for obesity. Both things can be true simultaneously.
Reminds me of a video I saw recently that pointed out the absurd number of calories professional athletes burn. Upshot of that video was that you almost certainly can run to lose weight. Just don't expect it to be an easy task.
At a personal level, I can also say that it is flat out hard to eat large amounts of food if you are staying active. The stereotype of wanting an after meal nap is legit.
It is also somewhat interesting to see other places try and contend with just how much food your average person in the US has at their ready disposal.
It ought to be obvious. A chocolate donut, large Frappuccino or pick your unhealthy food of choice are about equivalent to half an hour of running. Given how many people throw in a snack like that several times per day good luck burning that off with exercise.
One of the most straight forward things to lose weight is just limiting yourself to two or three actual meals, black coffee, tea, etc.
I have been, rather lazily I suppose, trying to tweak my diet in such as way as to lose weight; and with little to show for it.
I'm not sure that there is much if any processed food still in my diet (maybe just the English muffin in the morning?). I stopped buying/drinking soda pop decades ago (a low-hanging fruit indeed — I lost almost 10 pounds within a month of making that dietary change alone).
And since I have tried little things like switching to peanut butter that contains only peanuts (no salt, no sugar, not palm oil — sure, I have to stir it when I open it for the first time). I've moved to whole grain bread. Other small changes like that I can't remember right now.
I still have a BMI that's too high.
The only time I have significantly lost weight was when I was prepping for intestinal surgery nearly a decade ago. I was at the time worried that eating too much would literally kill me (I was worried about bursting my intestine) that I ate very small portions for each meal.
I'm not sure why I can't change my habits such that I continue to eat those small portions (now that the fear is gone).
I think it's great to try to eliminate foods that you believe aren't healthy (in any quantity) from your diet, but if you replace those foods with a quantity of other foods that keep your caloric intake more or less the same, you're not going to lose weight.
> ... I ate very small portions for each meal.
That's what does it. Decreasing the calories you eat.
> I'm not sure why I can't change my habits such that I continue to eat those small portions (now that the fear is gone).
Because, like all of us, you're only human, and human psychology, plus how our stomachs and brains signal each other, is complex and sometimes makes it really hard for us to achieve our goals. It sucks, but that's how it is. This is why the semaglutide weight loss drugs are proving so effective: they short-circuit some of that and help you just not want to eat as much food.
If drugs aren't for you, try counting calories, and use an app to help with it and help keep you honest. I experimented with it back in 2017 or so, and it actually did cause me to be more mindful about how much I ate, and made me think twice if I'd already hit my calorie budget for the day but wanted more food. I was pleasantly surprised to find I actually did lose weight. I didn't stick with it (don't remember why), but it did work for me for a time.
Diet to manage your weight. Exercise to manage your fitness.
It's real simple in theory and real difficult in practice. Super worth it, though. Your entire world starts opening up when things take less energy to do and you have more energy to give. It's very challenging to convey how important it is without living the experience.
Having lost 40lbs in the past couple of years, diet and walking have been key. It's just so much easier to burn fat by not eating it, than it is to try to burn it off with exercise. You'll find that burning 500 calories on a treadmill feels like an eternity, but eating one chocolate chip muffin? You can do that and gulp down a big glass of milk in 5 minutes like it's nothing.
Unsurprisingly, the title is sensationalist and not representative of the study. The study compares energy expenditure across different economic groups i.e. western people sitting in offices versus hunter-gatherers in Africa, and found that difference in energy expenditure does not account for differences in obesity, so points to consumption as the likely reason.
The sample dataset explicitly excluded 'athletes', so would exclude people that _are_ outrunning a bad diet. We know that a little weekly jog around the park doesn't mean you can eat a cheesecake every day, but anyone who has done extensive 'athletic' physical activity knows that if you don't up your calorie intake that you will lose weight. The study does not conclude, at all, that you cannot outrun a bad diet. Instead, it suggests "that dietary intake plays a far greater role than reduced energy expenditure in obesity related to economic development."
Edit: My point is specifically not about running. I am merely pointing out that if you read the study you will find that it is more of a study on economic development, and not really useful for personal or localised health advice. It observes that economically developed population groups may be more sedentary, but do not expend significantly more energy - so a hunter-gatherer picking berries all day does not burn significantly more energy than an office worker (at least not enough to explain why the office worker is obese). Therefore, the link between economic development and obesity is likely related to food (dietary intake) than daily activity.
Everyone in bodybuilding or adjacent crowds already knows this.
How fat you are is entirely a function of how much you eat. If you want to put on weight, you bulk by eating more. If you want to lose weight, you cut with reduced calories.
The idea you could instead bulk by doing less cardio and cut by doing more sounds completely crazy. In reality, you do more exercise on a bulk because, duh, you can recover from more volume when eating a surplus.
If you eat 4k calories but burn 5k, you'll lose a lot more weight than if you ate 1000 and burned 2000.
So running can help but you still need a calorie deficit. Eating and burning more boosts your metabolism - if you measure a body builder during a bulk they are like a furnace, burning 1-2k over baseline. They still put on fat but it's a lot less than what you'd think given the amounts they're eating.
This reminds a little of Usain Bolt famously having chicken nuggets before his final at the Beijing Olympics. Although hardly indicative of a bad diet that he may or may not have had.
I think as well there is some difficulty with variability between people that isn't clear or maybe doesn't matter at scale. The article linked study was across 43 nations with 4213 adults. Yet there may still be individuals who can argue differently. CICO (calories in vs calories out) must apply to us all, but the composition has an affect on what the body chooses to store vs how energised or hungry/satiated we feel. A bad diet could perhaps me we feel we have less enthusiasm for running or other activities. Age, lifestyle, and even cultural factors are massive in affecting metabolism (more the foremost) and of course what we consume (the latter two).
I run a fair amount (over 2000km/1200 miles in 2025) and find that once I start doing above ~70km/43 miles in a week whatever eating habits I have are indeed outcompeted by my running and weight loss is inevitable. Even so it does slow around a BMI of 23 for me for longer than I am able to be consistent with the running to observe further effects. Still my point is that my diet isn't anything to write home about and I anecdotally I feel that as far as weightloss is concerned I can very much outrun it.
> Yet there may still be individuals who can argue differently.
Of course! There are always outliers. But I think it is fair to say, as a general statement, that to lose or maintain weight, you have to focus on your diet, and exercise is not going to cut it. Sure, 1% of people might be able to "outrun their unhealthy diet", but that's not really useful information for the staggeringly vast majority of people out there. (Making up a percentage there; I think my point is still valid at 10%.)
1200 miles per year is a lot of running. That's 23 miles a week, or let's say ~6 miles, 4 days per week. Very few people are going to be able to -- or just flat out want to -- commit to that regimen.
I cut out drinks with sugar in them, eating after dinner, and in general just eating healthy meals.
I lift weights about 3 days a week, and am fairly fit strengthwise.
All this lowered my fat levels down to a reasonable level, but still left me with about 23% body fat and a bit of a belly, and that remained consistent. Trying to diet didn't really cause any maintainable change.
What I found has helped is doing a 24 hour fast once a week. This really means just eating one dinner a little earlier (4:30pm) and then skipping breakfast and lunch and drinking water with electrolytes added.
With keeping the rest of the days calorie intake the same, I have shaved off consistently 1 pound a week and 1/2" from my waistline.
This has been going for 5 weeks now, and I have gone from 23% to 19.7% based on navy body fat formula.
What is great is I have no cravings or feelings that I am depriving myself except for the last 8 hrs of the weekly fast. The rest of the week, I eat well.
My plan is to bring myself down to 15% and then continuing to measure. If I get above 15% I fast that week, if I don't then I don't fast, so it basically becomes like a controllable throttle.
I'm from a western country, but live outside the OECD. Currently on a trip back home and the food is disgusting.
Everything tastes sweet, is invariably hyper-processed, and supplied by a narrow pool of companies.
My diet in my host country isn't great, but it's so much easier to eat well. Fresh fruit and veg is more readily available, cheaper and frankly tastier. I wouldn't say people are any more or less sedentary, particularly in the capital city in which I live.
They accounted for total EE and basal EE, but the data they've supplied in the appendix doesn't track caloric intake.
This seems like a huge miss to me, as it is absolutely possible to have a sky-high TEE while being insanely fat (American football linebackers) and also having a low TEE and being skinny as a rail (by basically not eating, i.e. most fad diets).
Also, they categorize most of Africa as either horticulturalist, agropastoralist (why couldn't they say "farmers"???) or hunter-gatherer) despite the table at the bottom ranking their economies as "lowHDI", and the BEE for this cohort is N/A, which invalidates their PAL ratio (TEE/BEE).
Somewhat orthogonally related, I saw post on X by Nassim Taleb [1] concerning the idea that if you are very active then your heightened consumption of food may cover your nutrient bases better. So perhaps, loosely paraphrased, you could outrun and thus out-eat your nutrient imblance?
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[ 59.7 ms ] story [ 1588 ms ] threadI also think this is true related to food. Your body adjusts its metabolism based on the amount of food you eat as long as it's not chronic. That's why you can have competitive eaters that can eat a weeks worth of food and not be overweight. Spikiness and variability are probably good for you. Its funny that the Bryan Johnson types who closely control every calorie in their body have such a bad reaction to any variability. I don't know if its him, but I heard someone not be able to sleep and their levels got all messed up from one sweet. And their conclusion was sweets are so bad for you, rather than you're building your body to be too fragile to shocks.
The interesting thing is when this breaks down. Obviously if you eat a weeks worth of food every day for a sustained period of time, you will start to gain weight. Or if you run 12 miles every day, you will be in such a deficit that it won't be possible to lower your metabolism enough. Outside of the extremes, I think it's a cliff, where you have to have some kind of shock for some period of time for your body to react.
Eating as much pizza as I want, but going to bed after on empty stomach after running, or putting the running in the morning while doing about 12 to 16 hour slots of intermitted fasting? Hello, six-pack.
I used to spend ~4 hours a day training martial arts (kickboxing, BJJ, etc) during which time I could eat almost anything I wanted without gaining weight.
I'm sure if I had downed a cheesecake a day it would've been bad for me, but I was able to get away with a level of excess back then that I am unable to today.
So you can indeed outrun a bad diet, it just takes more running than most people want to do!
By very definition of a person is overweight, they got there by eating poorly, and are continuing to do so. They have eaten more energy than they use, this energy storage in fat.
Indeed, you can outrun a bad diet: we all know that. The study just shows that the lack of activity isn't the main reason for obesity. Both things can be true simultaneously.
At a personal level, I can also say that it is flat out hard to eat large amounts of food if you are staying active. The stereotype of wanting an after meal nap is legit.
It is also somewhat interesting to see other places try and contend with just how much food your average person in the US has at their ready disposal.
One of the most straight forward things to lose weight is just limiting yourself to two or three actual meals, black coffee, tea, etc.
I'm not sure that there is much if any processed food still in my diet (maybe just the English muffin in the morning?). I stopped buying/drinking soda pop decades ago (a low-hanging fruit indeed — I lost almost 10 pounds within a month of making that dietary change alone).
And since I have tried little things like switching to peanut butter that contains only peanuts (no salt, no sugar, not palm oil — sure, I have to stir it when I open it for the first time). I've moved to whole grain bread. Other small changes like that I can't remember right now.
I still have a BMI that's too high.
The only time I have significantly lost weight was when I was prepping for intestinal surgery nearly a decade ago. I was at the time worried that eating too much would literally kill me (I was worried about bursting my intestine) that I ate very small portions for each meal.
I'm not sure why I can't change my habits such that I continue to eat those small portions (now that the fear is gone).
> ... I ate very small portions for each meal.
That's what does it. Decreasing the calories you eat.
> I'm not sure why I can't change my habits such that I continue to eat those small portions (now that the fear is gone).
Because, like all of us, you're only human, and human psychology, plus how our stomachs and brains signal each other, is complex and sometimes makes it really hard for us to achieve our goals. It sucks, but that's how it is. This is why the semaglutide weight loss drugs are proving so effective: they short-circuit some of that and help you just not want to eat as much food.
If drugs aren't for you, try counting calories, and use an app to help with it and help keep you honest. I experimented with it back in 2017 or so, and it actually did cause me to be more mindful about how much I ate, and made me think twice if I'd already hit my calorie budget for the day but wanted more food. I was pleasantly surprised to find I actually did lose weight. I didn't stick with it (don't remember why), but it did work for me for a time.
It's real simple in theory and real difficult in practice. Super worth it, though. Your entire world starts opening up when things take less energy to do and you have more energy to give. It's very challenging to convey how important it is without living the experience.
The sample dataset explicitly excluded 'athletes', so would exclude people that _are_ outrunning a bad diet. We know that a little weekly jog around the park doesn't mean you can eat a cheesecake every day, but anyone who has done extensive 'athletic' physical activity knows that if you don't up your calorie intake that you will lose weight. The study does not conclude, at all, that you cannot outrun a bad diet. Instead, it suggests "that dietary intake plays a far greater role than reduced energy expenditure in obesity related to economic development."
Edit: My point is specifically not about running. I am merely pointing out that if you read the study you will find that it is more of a study on economic development, and not really useful for personal or localised health advice. It observes that economically developed population groups may be more sedentary, but do not expend significantly more energy - so a hunter-gatherer picking berries all day does not burn significantly more energy than an office worker (at least not enough to explain why the office worker is obese). Therefore, the link between economic development and obesity is likely related to food (dietary intake) than daily activity.
There are older studies: Epub 2015
It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet
https://pubmed.ncbi.nlm.nih.gov/25904145/
How fat you are is entirely a function of how much you eat. If you want to put on weight, you bulk by eating more. If you want to lose weight, you cut with reduced calories.
The idea you could instead bulk by doing less cardio and cut by doing more sounds completely crazy. In reality, you do more exercise on a bulk because, duh, you can recover from more volume when eating a surplus.
So running can help but you still need a calorie deficit. Eating and burning more boosts your metabolism - if you measure a body builder during a bulk they are like a furnace, burning 1-2k over baseline. They still put on fat but it's a lot less than what you'd think given the amounts they're eating.
I think as well there is some difficulty with variability between people that isn't clear or maybe doesn't matter at scale. The article linked study was across 43 nations with 4213 adults. Yet there may still be individuals who can argue differently. CICO (calories in vs calories out) must apply to us all, but the composition has an affect on what the body chooses to store vs how energised or hungry/satiated we feel. A bad diet could perhaps me we feel we have less enthusiasm for running or other activities. Age, lifestyle, and even cultural factors are massive in affecting metabolism (more the foremost) and of course what we consume (the latter two).
I run a fair amount (over 2000km/1200 miles in 2025) and find that once I start doing above ~70km/43 miles in a week whatever eating habits I have are indeed outcompeted by my running and weight loss is inevitable. Even so it does slow around a BMI of 23 for me for longer than I am able to be consistent with the running to observe further effects. Still my point is that my diet isn't anything to write home about and I anecdotally I feel that as far as weightloss is concerned I can very much outrun it.
Of course! There are always outliers. But I think it is fair to say, as a general statement, that to lose or maintain weight, you have to focus on your diet, and exercise is not going to cut it. Sure, 1% of people might be able to "outrun their unhealthy diet", but that's not really useful information for the staggeringly vast majority of people out there. (Making up a percentage there; I think my point is still valid at 10%.)
1200 miles per year is a lot of running. That's 23 miles a week, or let's say ~6 miles, 4 days per week. Very few people are going to be able to -- or just flat out want to -- commit to that regimen.
edit: grammar
I lift weights about 3 days a week, and am fairly fit strengthwise.
All this lowered my fat levels down to a reasonable level, but still left me with about 23% body fat and a bit of a belly, and that remained consistent. Trying to diet didn't really cause any maintainable change.
What I found has helped is doing a 24 hour fast once a week. This really means just eating one dinner a little earlier (4:30pm) and then skipping breakfast and lunch and drinking water with electrolytes added.
With keeping the rest of the days calorie intake the same, I have shaved off consistently 1 pound a week and 1/2" from my waistline.
This has been going for 5 weeks now, and I have gone from 23% to 19.7% based on navy body fat formula.
What is great is I have no cravings or feelings that I am depriving myself except for the last 8 hrs of the weekly fast. The rest of the week, I eat well.
My plan is to bring myself down to 15% and then continuing to measure. If I get above 15% I fast that week, if I don't then I don't fast, so it basically becomes like a controllable throttle.
Another protocol that is sustainable is 4:3, ie 4 days of normal eating and 3 of intermittent fasting.
Everything tastes sweet, is invariably hyper-processed, and supplied by a narrow pool of companies.
My diet in my host country isn't great, but it's so much easier to eat well. Fresh fruit and veg is more readily available, cheaper and frankly tastier. I wouldn't say people are any more or less sedentary, particularly in the capital city in which I live.
The study is supported by my limited experience.
They accounted for total EE and basal EE, but the data they've supplied in the appendix doesn't track caloric intake.
This seems like a huge miss to me, as it is absolutely possible to have a sky-high TEE while being insanely fat (American football linebackers) and also having a low TEE and being skinny as a rail (by basically not eating, i.e. most fad diets).
Also, they categorize most of Africa as either horticulturalist, agropastoralist (why couldn't they say "farmers"???) or hunter-gatherer) despite the table at the bottom ranking their economies as "lowHDI", and the BEE for this cohort is N/A, which invalidates their PAL ratio (TEE/BEE).
idk this seems like a "fat ppl bad" study to me.
For example jogging at about 7mph for 2 hours a day for a 180lb man would burn about 13,200 calories a week. I know people who jog like this.
Or I know people who cycle 250-400 miles a week which burns about 17,000-27,000 calories a week!
1: https://x.com/nntaleb/status/1684885140093206528