[jsprogrammer]

There is at least one person in these comments extolling the virtues of keto viz a viz quick weight loss without exercise.

I don't know what a normal low fat diet is, but the overruling factor in weight loss/gain is the ratio of work (exercise) to energy input (calories).

[collyw]

Physics, years of evidence and common sense down voted on HN where solyent is seen as a good thing.

[rayiner]

The physics is that exercise burns so few calories it's not worthwhile from a weight loss point of view.

[jsprogrammer]

Where have those physics been documented?

I want to see the same person:

    'immobile
    'sitting most of the time, with short commutes and shopping trips
    'intensely exercising 1 hr a day
    'actively working out throughout the day

while maintaining their current diet and weight.

[schrodinger]

These aren't independent variables. The point is that a half an hour run only burns around 300-400 calories, a deficit which could more easily be accomplished by diet. Also, it's possible that the run would increase your appetite.

The point isn't that exercise _can't_ work, it's that aiming for dietary changes has a higher average ROI than exercise.

[jsprogrammer]

"these"? I don't know what that refers to.

No one has argued that there is a lower than average ROI (you get paid for not eating?) from exercise.

[DrScump]

It's not physics, it's biochemistry.

But it's more complicated than that. Genetics cause one's predisposition as to how responsive a person is to cardio; see the University of Bath study and/or Michael Mosley's "The Truth About Exercise".

[will_brown]

>but the overruling factor in weight loss/gain is the ratio of work (exercise) to energy input (calories).

I don't think you are off, but the key is not weight loss/gain...the key is healthy weight loss/gain and that has everything to do with what you consume.

[DigitalJack]

Calories_out = Calories_in - Calories_stored.

Caloric source matters, your body does different things with different sources.

Your metabolism will be reduced by reducing calories in. They are not independent variables.