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Comment by shadowtree | Hacker News Reader

Not my experience, let me explain:

I notice that I have a baseline of appetite, hunger. Going below that makes me deeply uncomfortable. At the same time, I know that I don't need too much exercise to come to a calorie neutrality or slight deficit - but I can't reach that energy expenditure with a sedentary lifestyle.

If I do a 30min run every day, plus walk to work (another 30min), I spend enough calories so I can eat comfortably (still healthy).

A tracker like the Apple Watch helps to see this in action. Closing your rings in the city? Easy. Closing your rings while car centric? Hard.

People should not need to diet. They should spend enough calories to burn off excess food. Note I am talking about healthy BMI, not Instagram fitness model levels. Dad bod, etc. Not morbidly obese.

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>> People should not need to diet. They should spend enough calories to burn off excess food

This is bad advice, it's been shown over and over again that in the long term people don't manage to lose weight by exercising. They give up, don't exercise enough, overestimate how many calories they burnt, over-compensate by eating more and/or unhealthier ('because I earned it after taking a run'), etc.

You don't have to 'diet' to lose weight, just try to eat a little less each day, and watch what you are eating. Only 100 calories less than what you need each day, and you'll steadily lose maybe ~3KG a year.

Metabolism increases can also affect you long after a workout, and building muscle instead of fat is also beneficial for the system as a whole. These cannot be recreated with just diet.

However, exercise is the largest driving factor in health _not_ weight https://www.hopkinsmedicine.org/news/media/releases/treadmil....

For weightloss _diet and exercise_ is the way to go: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4429709/.

>Objectively measured physical activity may not be the key determinant of unhealthy weight gain in children.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044163/

>Prospective studies, however, find little evidence of the more physically active members of a population gaining less excess weight than those who are the least physically active.

https://www.ncbi.nlm.nih.gov/pubmed/21832897?dopt=Abstract

>TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.

https://academic.oup.com/ajcn/article/93/2/427/4597724

> However, exercise is the largest driving factor in health _not_ weight

Citing a bunch of studies about obesity changes nothing about the fact that _exercise_ is more important to health outcomes than _weight_.

Another source for you: https://care.diabetesjournals.org/content/27/1/83

> There was no significant trend across BMI categories for mortality after adjustment for fitness.

Being skinny isn't being healthy, being _fit_ is being healthy.

>Citing a bunch of studies about obesity changes nothing about the fact that _exercise_ is more important to health outcomes than _weight_.

This is pretty funny. They directly address and contradict the point your trying to make. Even the source you posted contradicts what you are trying to argue. Nice try though

Is that research for level of activity in general or for "exercise"?

In my experience diet is necessary to lose weight, but exercise makes dieting a lot easier.

>If I do a 30min run every day, plus walk to work (another 30min), I spend enough calories so I can eat comfortably (still healthy).

An Olympic level athlete might burn 30 kcal per minute at their best. I would bet a regular person burns at most 15 kcal per minute while running, so that's 450 kcal for a 30 min run, and maybe a couple hundred more for a walk. People consume that in a single large sugary coffee or soda drink. You can't ignore inputs.

30 kcal per minute would be very difficult to sustain except for a very short burst of time (like 2-5 minutes) in a peak performance scenario (such as an end-of-season race that the athlete is very well tapered and rested for).

My personal numbers for my regular training runs are about 11-12 kcal per minute. I can exceed 15 kcal per minute for very hard workouts or racing but I cannot train appropriately while doing that regularly. I'm a relatively seasoned runner but I don't focus on 800m-1500m which is where it might be possible to see numbers exceeding 20 kcal per minute.

In order for this to make sense for the purposes of lifestyle modification, you also have to subtract the calories that you would have burned had you not been exercising. IE if you had not run for that 30 minutes, you would still have been burning calories, either completely sedentary BMR or some other NEAT. This makes it even a worse deal to exercise for the sake of burning calories.

I dont think they are ignoring input. Of course, when soda and lots of sugar is still part of your diet all bets are off - those are the basics that have to be fixed first. This has been repeated and emphasized over and over. However, in addition you can‘t just ignore the benefits of exercise and the extra budget of a few hundred calories it provides daily.

I recommend to get an Apple Watch (or any good fitness tracker) and a smart scale. After some time you can pretty easily and reliably predict your daily weight development simply based on your most recent diet and exercise.

Having an extra negative 400 to 500 calorie offset on a daily basis can be incredibly helpful considering a lot of creeping weight gain is caused by a caloric surplus of only a couple hundred per day.

From the looks of many Americans I’ve seen, their problem is a lot more than a couple hundred kcal per day.

A couple hundred kcal per day for 10 years is about 200lb.

Thank you for putting some perspective on this! It's a huge aggregate in the long run.

It doesn't work like he says. You can't just sum up the number of calories and convert it to pounds of fat. If you eat a few hundred calories too many you will rise in weight. But increasing your weight means your metabolism will increase. In the end you will reach an equilibrium were your weight is high enough that your metabolism equals your intake, and you will stop gaining weight.

Let's take a 5"10 male aged 25 weight 170 pounds. According to some calculator they will have a basal metabolism (how much you use if you stay in bed all day) of 1850 kcal / day. Lets say they eat 450 kcal / day too much. i.e. 2300 kcal / day. By running the metabolism calculator backwards we find that they stabilize on a weight of 245 pounds.

Thats a seriously overweight, to be sure, but it is also well below 200 pounds of extra weight.

Yes, there are 2nd order effects, and there are also a bunch of assumptions in basal rate calculations, and conversion efficiency etc. Your assumption that the current day surplus doesn't carry forward (i.e. that as someone gets heavier they done increase intake to account for increased basal metabolism) is also a pretty strong one.

Anyway I could have been clearer, but my point wasn't to suggest that you would end up exactly 200lb heavier, but that your calorie surplus adds up to roughly 200lb - exactly what happens to it depends on a lot of things.

This is response to someone who suggested they hadd seen a lot of clearly obese people who couldn't have got there on a few hundred extra kcal per day - however that doesn't seem accurate.

650 calories a day is easily the difference for a lot of people's freedom of diet choices/ eating what they want. And this is a very moderate level of activity/exercise. Why are you so intent on discounting it?

I’m claiming that number of excess calories consumed easily surpasses a realistic level of exercise, based on eating habits I see.

>People should not need to diet. They should spend enough calories to burn off excess food.

It's unlikely a 30m run and a 30m walk is going to burn off their excess calories.

Not my experience, let me explain:

Experience and anecdote does not substitute for real scientific evidence. Research suggests that your body compensate for any activity expenditure to maintain caloric burn within that specific range. This is known as constrained total energy expenditure.

If I do a 30min run every day, plus walk to work (another 30min), I spend enough calories so I can eat comfortably (still healthy).

A tracker like the Apple Watch helps to see this in action. Closing your rings in the city? Easy. Closing your rings while car centric? Hard.

I don't trust smartwatches and other devices to track caloric expenditure accurately given that they seemed to have constantly overestimate how much I burn.

This does not dissuade me from making sure that I get at least an hour of exercise everyday.

People should not need to diet. They should spend enough calories to burn off excess food. Note I am talking about healthy BMI, not Instagram fitness model levels. Dad bod, etc. Not morbidly obese.

I agree that people should not do anything special, but here we are in a food environment that makes this difficult.

> Not my experience, let me explain:

>> Experience and anecdote does not substitute for real scientific evidence. My research suggests that...

Can you cite your research. It's hard to criticize someone for giving an anecdote then going on to cite 'your research without citing it.

Here are a few

>Objectively measured physical activity may not be the key determinant of unhealthy weight gain in children. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044163/

>Prospective studies, however, find little evidence of the more physically active members of a population gaining less excess weight than those who are the least physically active.

https://www.ncbi.nlm.nih.gov/pubmed/21832897?dopt=Abstract

https://academic.oup.com/ajcn/article/93/2/427/4597724

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