[Therefore, in order to lose weight, he needs to focus on refining his diet.

And so you agree, then, that your previous statement, "Diet is for weight loss; exercise is for fitness," was bullshit.

Jay

Watch your diet and get a mountain bike, it's a lot more fun than jogging.

Hey Jay, I found this atricle online: http://jt512.dyndns.org/blog/?p=96
The author is a bit of a windbag but it contains some good info about losing weight. It's 9 paragraphs long but only has a couple of sentences about exercise (the rest is about what to eat) so it reiterates my beliefs that to lose weight, one must focus on diet rather than exercise.

Hey Jay, I found this atricle online: http://jt512.dyndns.org/blog/?p=96
The author is a bit of a windbag but it contains some good info about losing weight. It's 9 paragraphs long but only has a couple of sentences about exercise (the rest is about what to eat) so it reiterates my beliefs that to lose weight, one must focus on diet rather than exercise.

Your comments seem to too abstract. Can you explain your strategy to lose 2+lbs of fat per week that would be sustainable for the average 150lb male through diet alone? Or the majority through diet? Thats like 1000Cals/day deficit.

Who? Me? I never said anything about a 150lb male losing 2 pounds per week. That sounds extreme unless said male is like 5'3".
I'm just under 150 pounds at 5'11". I could lose 2 pounds in a day but thats only after Indian food and a lot of coffee. And that is not sustainable.

Fine, ignore the exact weight of the person. 2 lbs/week is a pretty moderate weight loss goal that can be obtained by motivated individuals. IME this is done by combining both exersize and nutrition, but you claim that it can be done by focusing mainly on nutrition.

A caloric deficit is a caloric deficit, whether it's the result of an overall reduction in caloric intake, or reduced intake along with exercise.

I've assumed the OP was already working out in some form or another. My advice to him is that in order to lose weight he needs to focus on the quantity/quality of what he eats and not the amount of exercise that he does.

I've been getting a lot better at climbing recently but for the life of me I can't burn fat.

A caloric deficit is a caloric deficit, whether it's the result of an overall reduction in caloric intake, or reduced intake along with exercise.

Christ, enough bullshit already. Weight loss results from negative energy balance, that is, when total energy expenditures exceed total energy intake. It doesn't matter whether the energy deficit results from diet, exercise, or a combination.

There's a pile of research on this topic. I'm pretty familiar with it, as I earn money for climbing trips by being a professor of medicine. The generalization that diet is for weight loss, exercise is for fitness is roughly true, for typical recreational levels of exercise (i.e., not marathon and ultramarathon running or cycling, or amateur-elite or professional level training). Yes, the overall point is energy deficit, but creating the deficit through restricting intake, particularly intake of high-glycemic-index low-nutritional-value foods, is the most effective approach. That's the bottom line from quite a lot of well-done research.

That is not to say that exercise doesn't contribute. It does, in several ways. Though not as important as diet, it does contribute directly to the calorie deficit. It also protects muscle mass. With diet alone, muscle gets burned along with fat as the body deals with energy deficit. So, exercise is quite important in becoming healthier, as opposed to merely lighter. Exercise also makes it easier to lose weight when dieting, because it helps prevent the reduced metabolic rate that otherwise tends to happen when calories are restricted.

The kind of exercise also matters. With all due respect to the trainer who commented, high-intensity exercise is not the optimal choice for weight loss. (For fitness, it is.) High-intensity exercise is heavily glycogen-dependent, and tends not to mobilize fat stores. Long-duration low-intensity exercise burns fat more effectively. Two hours of brisk hiking or cycling at a moderate pace four or five days a week is a pretty good target to aim for.

The kind of exercise also matters. With all due respect to the trainer who commented, high-intensity exercise is not the optimal choice for weight loss. (For fitness, it is.) High-intensity exercise is heavily glycogen-dependent, and tends not to mobilize fat stores.

Long-duration low-intensity exercise burns fat more effectively. Two hours of brisk hiking or cycling at a moderate pace four or five days a week is a pretty good target to aim for.

All that matters is the amount of the caloric deficit, not the fuel mix burned...

In theory one might think so. However, in practice it doesn't work out. Fat doesn't get burned to replace the carb intake that goes into replenishing glycogen (well, it does but just not to a useful extent). People just eat more after high-intensity exercise, the glycogen stores get replenished but the fat stores are protected. .

Worse, people crave carbs after high-intensity exercise, then spike their glucose and insulin levels, and can even end up adding fat.

In theory one might think so. However, in practice it doesn't work out. ...

Okay, so now you're claiming that high-intensity exercise actually causes gains in body fat.

The kind of exercise also matters. With all due respect to the trainer who commented, high-intensity exercise is not the optimal choice for weight loss. (For fitness, it is.) High-intensity exercise is heavily glycogen-dependent, and tends not to mobilize fat stores. Long-duration low-intensity exercise burns fat more effectively. Two hours of brisk hiking or cycling at a moderate pace four or five days a week is a pretty good target to aim for.

Given, I am internet based researcher, but almost everything is just one click away. Here is one study that present slightly different commentary.
In short - aerobic at 70% of VO2Max increases resting energy expenditure
The commentary also emphasizes that more fit individuals, that is the ones with higher VO2Max, will burn more energy even at the same relative load. I don't feel like searching for references showing that VO2Max can only be increased if exercising at high intensity levels.

Then, there is study , which also presents similar results.
In short - 70% HIIT regime resulted in higher subcutaneous fat loss than 50% regime.

Perhaps there were studies done recently with different outcomes?

The problem that kf8mo is referring to is that humans suck at regulation, and when doing HIIT they end up eating more, canceling out much of the benefit. People are lazy sacks of shit, but truely motivated people will get the best results training at higher intensities and controlling their diet properly