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Comment by narag | Hacker News Reader

Walking less is not the cause of the obesity, more like the other way around: if you don't need to walk, you can afford to overeat until you're obese. Also the pleasure of walking and exercising must be replaced with something else.

But exercise has very little effect on weight compared to diet. It's a known fact, even for the fans of counting calories. Just see the tables of inputs and outputs.

Eating less and avoiding sugar and processed food is mostly enough, if not to be slim, at least to keep you reasonable healthy.

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> But exercise has very little effect on weight compared to diet. It's a known fact, even for the fans of counting calories. Just see the tables of inputs and outputs.

Also, some studies suggest that up to some threshold, exercise reallocates those calories from autonomic functions rather than actually adding to total expenditure [1]. It's been further speculated based on this that some of the health benefit of exercise might simply be a result of taking energy away from anxiety/stress responses.

[1] https://pubmed.ncbi.nlm.nih.gov/22848382/

>But exercise has very little effect on weight compared to diet. It's a known fact, even for the fans of counting calories.

It reduces the weight of all the fat you're carrying around. Even if exercise doesn't make you lighter it still makes you leaner.

I don't get it. The exercise doesn't help lose tissue. the caloric deficit does, and as parent said, that is way easier to achieve through reduced intake.

People often find exercise easier to modify than diet, or even for exercise to make following a healthy diet easier. The process of building muscle can create a caloric deficit.

> But exercise has very little effect on weight compared to diet. It's a known fact, even for the fans of counting calories.

I recognize that this is conventional wisdom, but it hasn't been borne out by my own results losing well over 100 pounds / roughly 40% of my body weight over the course of several years.

I've counted calories strictly, with the same methodology and same limit, and documented weight regularly, both during low-activity low-altitude winters and medium-activity, high-altitude summers. The results I got, over the major windows in which I got them, were as follows:

    altitude | activity | loss | weeks | lbs/week | implicit daily caloric deficit @ 3500 cal/lb
    high     | high     | 60   | 14    |  4.28    | 2140
    low      | medium   |  0   |  6    |  0.00    |    0
    low      | low      | 17   | 22    |  0.76    |  381
    high     | low-med  | 47   | 30    |  1.57    |  783
    low      | low      | -2   | 22    | -0.09    | - 45
    high     | medium   | 10   |  4    |  2.50    | 1250

I'm defining "high" activity here as "regularly exercising to physical exhaustion", "medium" as "regularly climbing up hills that cause me to breathe heavily but don't exhaust me", and "low" as "regular walking but nothing that strains my body meaningfully".

This is now data collected over years of weight loss and multiple seasonal changes in location and activity, and I find it difficult to explain this within the context of standard weight loss advice. Exercise at altitude seems to burn far more calories than it "should", by a factor of four or five times.

I walked a mile or two every other day on average across this period, meaning the only difference is a roughly 15 to 30-minute walk up a steep slope roughly every other day. A typical calculator will tell you this "should" burn on the order of 100-150 calories, but the data suggests it's closer to 500-1000.

I'm not a doctor, so I don't know why this is. I've largely ruled out:

- Diet, which is conserved across locations fairly well (I cook most of my own food using widely-available ingredients)

- Seasonal effects, unless they happen to produce very sharp discontinuities at the exact time I relocate each year

- Emotional state, since these results have been robust to both positive and negative emotional states in both locations

- Temperature, which is near-constant year round (because I live in warm places in winter and cold places in summer)

- Groundwater, because I drink almost entirely bottled water and not local water supplies

- Major underlying medical causes (my bloodwork is great and I don't have any reason to think I'm sick)

I have a working hypothesis that the studies that established calorie burn from exercise (which I believe largely did it by measuring CO2 exhalation) were missing a great deal of the actual energy cost, because the costs of anaerobic respiration take place over hours following exercise and not just during it. But I also can't imagine people with actual medical expertise haven't thought of this before. A negative correlation between altitude and obesity rates is well-established, so something is going on.

In any case, the data is the data, and it points very strongly towards altitude and exercise, synergistically, being almost exclusively the source of my own weight loss.

On a fundamental level, if you reduce input you will have less storage costs.

I wish this was understood more. To burn 1K kcalories takes considerable effort. To not ingest them, avoid that pizza. Hell, pizza +beer or coke probably is way more.

1k calories is also a pissload of food.

I dont get the point of saying excercise doesnt make you lose weight. It increases your caloric need, so if you dont eat to make up for it, then ya it absolutely helps.

I struggle greatly to diet hard enough to lose weight if im sedentary. Its extremely easy when doing 3 1hr strength workouts a week, and lik 20 mins of cardio a day. Like its a struggle to eat enough to maintain weight.

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