You can burn nearly 400 calories running for 30 minutes at a relatively moderate pace.

I think the point is, you can consume nearly 400 calories drinking a smoothie in 30 seconds.

Diet is and always will be the key to weight loss.

No one is suggesting that you can out run an increasing calorie surplus. You can however keep your diet the same and add two hours of running to your week and lose weight.

Ask anyone who has been obese and subsequently lost weight and they'll tell you the same thing. Eating less is both a sufficient and necessary condition to losing weight. Exercise is neither sufficient nor necessary because the caloric surplus these people are on significantly exceeds the amount that you can practically burn through exercise. While you're right that exercise can help on the margin, it's just not a useful intervention that moves the needle much as far as weight loss goes.

Yup, can confirm - for me, at least.

At one stage, I started walking home from work at my fastest pace. 5 miles, 5 days a week. No other lifestyle changes. No significant weight loss.

A few years later, I started tracking calories with myfitnesspal and keeping to a limit (1600 initially, 1400 when it became easier). No exercise, but steady and impressive weight loss. I seem to have kept most of it off. I think a lot of it becomes psychological - not being afraid to feel appetite or skip meals if already satiated from earlier.

I don't know why anyone here has the idea that I'm arguing that exercise alone is key for weight loss. I have very clearly only claimed that all else equal increasing exertion will lead to a calorie deficit.

> While you're right that exercise can help on the margin, it's just not a useful intervention that moves the needle much as far as weight loss goes.

There's more to exercise than just the thermodynamic effects of calorie expenditure. Building muscle and/or cardiovascular capacity will improve your quality of life and will complement any weight loss. You can improve your mental health by becoming more physically active, and this is well established. Those mental health gains and physical health improvements make it easier to maintain a better diet. Beyond the marginal, but significant calorie expenditures you can create a positive feedback loop.

Only assuming you have a steady body weight and diet, which is a very bad assumption for most overweight and obese people.

Not to mention, the processes in your body are way more complex than all this makes them out to be. For moderate exercise, after an adaptation period of a few weeks to months, there is almost no calorie impact from the exercise itself on your total calorie expenditure: your metabolism adjusts and various internal processes are deprioritized to prioritize the exercise.

This is in fact a major component of why exercise is so healthy: it doesn't do much for weight loss, but it stops/slows down all sorts of unnecessary processes in the body that are actively harming your overall health.

> almost no calorie impact from the exercise itself on your total calorie expenditure

This is categorically false. You don’t have a magical metabolic adjustment, you simply become more efficient in performing an exercise but the calorie use never drops to effectively zero like you’re claiming. Think about this for a second, it makes no sense to think that running could ever consume zero calories, basic physics still apply.

I explained this very clearly. The exercise of course has to consume calories. But that doesn't mean they have to be calories in excess of your base metabolic rate. What happens is that your base metabolic rate decreases more or less commensurately with the amount of extra calories you're consuming through excercise. If your BMR was 2000 Cal/day when doing 0 calories from excercise per day, and then you start exercising for 300 Cal/day, your BMR will decrease to about 1700 Cal after some time of maintaining this routine.

You are completely wrong though. There's a large body of work dating back decades pointing to BMR increasing with exercise.

[1]https://pubmed.ncbi.nlm.nih.gov/2204100/

[2] https://pubmed.ncbi.nlm.nih.gov/8775359/

And the newer work is starting to find the limits that I mentioned. There are several caveats that I didn't mention for brevity:

- no exercise vs moderate exercise vs athlete-level exercise are very different cases. Doing some exercise does increase total energy expenditure vs no exercise, but the amount doesn't change significantly until you get to pro-athlete levels. That is, going from 2000/0 Cal (BMR/exercise) to 200 Cal of exercise might take you to, say, 2100/200 Cal; but moving from 200 Cal of daily exercise to 400 Cal of daily exercise will not take you to a higher TEE; unless you reach the stage where you are doing, say, 1000+ Cal worth of daily exercise (specific numbers pulled from thin air, just trying to illustrate the concept).

- Muscle mass is a confounder for what I was claiming - more exercise leads to increased muscle mass normally, and that does lead to an increase in BMR very directly.

Overall the more correct claim I should have made would be "exercising more, assuming you are not very sedentary, will not lead to increases in total energy expenditure beyond those gained from muscle mass increase, unless you get to pro athlete levels of exercise".

Here are some studies backing me up:

- https://journals.physiology.org/doi/full/10.1152/physiol.000...

- https://onlinelibrary.wiley.com/doi/10.1002/ajhb.22711

- https://www.cell.com/fulltext/S0960-9822(15)01577-8

I'm taking all of these links from the Kurzgesagt sources for their video on exercise: https://sites.google.com/view/sources-workoutparadox. They link to more specific claims from each paper, and to a bunch of other papers.

Then eat a "healthy" avocado toast and gain 400 calories back.

And an average human can probably ingest 400 calories in under a minute, with significantly less fatigue.

Who is arguing otherwise?

It's still 400 calories deficit regardless

Not true, on two counts:

- one, your body may crave more food because of the energy loss - the Lipostat model suggests that your body has a target weight (well, fat level, more precisley), and will adjust hunger up if calory expenditure goes up

- your internal processes use way more energy than you can consume through exercise in a modern lifestyle (2000+ calories a day just from sitting still, for many adult males), and there is a lot of room for the body to adjust those up and down to make up for the extra exercise to keep up your current weight. So if you consume 2000 Cal a day with 0 Cal from exercise, with moderate exercise you will end up conauming 1600 Cal a day from internal processes + 400 Cal a day from exercise after some time (a one time run will absolutely consume extra, if your run every day, you'll get less and less extra Cal from your runs, until you reach about net 0, assuming you're not increasing the amount of exercise constantly).

Being able to run for 30 minutes implies that you are already fit.

And likely already at a low body fat otherwise it would be crippling for your joints.

If one were getting the doctor recommended amount of exercise running for 30 minutes or some commensurate activity would not be intimidating, and it's far less likely that you would have a weight issue in the first place. Doctors recommend about 150 minutes of moderate intensity exercise per week. Imagine doing that every week, for your whole life.

30 mins of running = 5km marathon.

Most people can walk 30 mins but I would doubt if most can run a marathon.

That’s why there are programs like Couch to 5K which slowly work up to a nonstop 30 minute run. It doesn’t even take that much determination and it’s practically designed for obese people. I was able to complete it weeks ahead of schedule at a BMI of 30 and the 4-5/wk runs it enabled helped me lose 35 pounds in 2024 - the vast majority of the weightloss happening during the weeks that I ran.

Nitpick: a marathon is 42 kilometers (by definition). Most people would struggle to even walk that.

There's no such thing as a 5km marathon, that's a contradicition in terms. However, if one were running 150 minutes a week on a regular basis then a (42km) marathon would likely not be too intimidating a prospect. Suffice to say, most are not getting in their doctor recommended level of exercise.

Sadly in the first minute after the run a milkshake will add back 400 calories.

The insane efficiency of the body is the problem.

30 minutes of agony -- the jog -- can be thrown out the window with literally one minute (60 seconds) of overeating.

That's why I think exercise plus GLP-1 medications once a year might be the future gold standard for weight loss and maintenance.

Any thoughts on GLP-1 meds being the game changer we need?

It’s more the insane energy density of the milkshake. If you spent the same time eating a carrot you wouldn’t have this issue.

Don't GLP-1 meds currently have bad side effects for a lot of people?

The only game changer is to stop taking shortcuts and start really taking care of yourself.

GLP-1 are crutches and if you need it once a year.

But that hasn't been working for the average American, right?

Aging is rough.

And the high calorie to nutrient ratio in this country makes it really hard to avoid adding pounds.

This country is calorie and diet obsessed, and yet average weight seems to keep increasing.