[codahale]

1,000 calories, considering the modern possibilities, isn't that much. I mean, that's a bit less than two slices of toast with Nutella.

Weight loss programs have to focus on preempting and managing appetite. There's a wealth of studies connecting exercise to increased appetite (c.f. OP), especially focused, running-at-the-gym, doing-penance-for-those-donuts exercise. (Low-level activity—walking around, say—doesn't seem to provoke the same uptick in hunger. But it also burns way, way less calories.)

Your counterfactual assumes that the runner isn't more likely to eat an additional 2,000 calories, which is to say, they're already managing their appetite. If you can manage your appetite, then go for a goddamn run already. You'll be happier for it. If you're not managing your appetite, work on that—exercise will not help you lose weight until you do.

There's a great book—The End Of Overeating—which details the intersection of modern food science, evolutionary psychology, cognitive psychology, and human physiology. If you're interested, give it a go.

(BTW, bringing up elite athletes doesn't help the discussion—elite athletes regularly have 1.5-2 times the VO² max of even extremely fit people. Hell, five-time Tour de France winner Miguel Indurain could circulate 7L of oxygenated blood per minute compared with the 5-6L of his competitors and 3-4L for the fitter of us regular people. Human physiology has a statistical distribution, and bringing up people many standard deviations from the mean doesn't help any of us regular schmucks. My mutant power certainly does not involve my metabolism.)

[gaius]

1,000 calories, considering the modern possibilities, isn't that much. I mean, that's a bit less than two slices of toast with Nutella.

Yes, it is VERY difficult to out-train a bad diet. There is an example I use with friends, which is if you drink 5 pints of beer, you'll need to run 10 miles to burn that off (really). Have a pizza or a kebab on the way home, another 10 miles. Have a fry-up for breakfast, another 10 miles. So even if you ran a Marathon tomorrow, with your hangover, you've still gained fat from one Friday night. And you're doing again on Saturday night too.

On the subject, of athletes, everyone at the top of any sport is a genetic freak. That's not to disparage the effort they put in. But hey, Michael Phelps didn't get his extraordinarily long armspan from training. He didn't get his flipper-shaped feet from training. He was born with them. And he was born with an extraordinary metabolism too.

[mr_luc]

I agree that it's difficult to out-train a bad diet. But

1) Remember, we're counting the difference between what you need to eat and what you do eat. So although crazily irresponsible people doubtless are regularly eating 5000+ calorie diets, day in and day out, the amount they need to burn off to zero out would then be around 2000+ calories.

2) Impractical is not impossible. Even if you OVEREAT by 3000 calories per day, if you spent all day running and resting/drinking water from running, you could do it.

Exercise CAN make people thin. ;) I'm not saying that for a given someone, you couldn't eat enough to take yourself out of contention, but the answer to "Can exercise make you thin?" is "yes."

What I object to most in the article title is the implication that people are working hard, but somehow wasting their effort.

"Oh, the problem is that you've been getting up an hour early every morning to run and run and run, and have been undoing all of your hard work by eating Hardees Thickburgers 3 times a day!"

If you have the self-discipline to run regularly, you have the self-discipline necessary to complement it with the MINIMUM of dietary caution necessary to let it work for you.

[caffeine]

It's important to distinguish weight loss from fat loss. We want the latter - the former in itself is not particularly desirable (except perhaps for ice fishing).

- When I exercise, I tend to build muscle (and sore legs).

- When I eat less, I tend to lose some weight.

- When I exercise but eat more, weight goes up - because I'm gaining muscle.

So far, so good. But the above is completely meaningless. What really matters is:

- If I'm exercising a lot and eating reasonably, my weight goes up, BUT my %BF (percent body fat) goes down, because I'm gaining more muscle than fat.

- If I'm doing low-intensity exercise and eating sparingly, my weight goes down, but my %BF remains stable.

- If I exercise like crazy and eat very little, my weight goes down and my % BF goes down. This happens rarely because it requires inhuman willpower.

The point of this (admittedly anecdotal) chart is that weight change and %BF change are NOT correlated. In particular, the way one achieves a low body fat is:

1. Increase muscle, lowering %BF.

2. Lower overall weight, causing net fat loss AND muscle loss, probably increasing %BF slightly.

3. GOTO 1.

If you lose more %BF on step 1 than you gained on step 2, you win. This zig-zag is what body builders do, because it's nearly the only method that works. And step 2 is very diet-sensitive, and rather finicky.

And that is why the article sounded stupid to me. The study, in particular, of women who exercised intensively compared to those who didn't. I hope they measured % body fat in that study, because it's the only thing that matters when talking about obesity.

When the article says something like "Everybody lost a bit of weight, but some of the exercisers gained weight! So exercise doesn't make you thin." That's crap. "Lean" is a measure of % body fat, not total body mass. The exercisers probably decreased %BF if their weight remained stable. In other words, they probably look better now than they did.

[gaius]

if you spent all day running and resting/drinking water from running, you could do it.

Well, I am a Marathon runner. I know what burning 3000 extra calories in a day feels like. There is no way I could do that every day, and the average person is a LOT less fit than me.

Exercise is important for many reasons, but fat loss is mostly about the diet.

[nopassrecover]

1000 calories for toast with Nutella!?

I assume by calories you mean kilocalories in which case you are probably looking around 1000 KJ (kilojoules) for two slices of toast with Nutella. That's around 239 (kilo)calories.

[codahale]

Wheat bread's about 75 calories a slice, so 150 for just the bread. I don't know about you, but I put it on thick—maybe a serving-and-a-half per slice, which according to the Nutella website is 570 calories. So 720 total. Not 1,000, but closer to it than 239.

[bhousel]

Really? here are the numbers I just got for comparison off the containers (both are serving size 2 Tbsp)

   Nutella:                190 calories, 11g fat, 21g sugar, 3g protein
   Organic Peanut Butter:  210 calories, 18g fat, 2g sugar, 8g protein

Nutella isn't really that bad. I'll sometimes eat it on bread before a long run.

[codahale]

A serving size is 2Tbsp, which is what I put on a serving size of bread (1 slice) when I'm paying attention to how much I'm putting on. Like I said, though, I tend to slather it on (mainly because Nutella is so damn good)—so I'm really getting 1.5-2 servings of Nutella per slice.

Two slices—75kcal * 2—and a hunk of Nutella—190kcal * 3—is way the hell more calories than I should be eating as a snack (720kcal). Veeeery easy to go overboard.

[nopassrecover]

Okay wow I had no idea that Nutella was that high. That's freaking insane. You could have 2 and a half Snickers for that.

[Retric]

If you think of exercise as 30 minutes a day 3 times a week then diet is by far more important. But, at extreme levels of exercise it's hard to eat enough calories to keep from losing weight.

At the true elite level Michael Phelps is fueled by 12,000 calorie a day diet, eating that much food just hard. Think 60 Twinkies a day plus a 3000 calorie diet.

But even 1/2 that and most people would still have problems keeping up for months at a time. The average human body could do 8 hours of exercise a day 7 days a week for years after training. So we don't really need to look at the true extremes of human capability to find a level of exercise that will balance all, but the most ridicules diet.

PS: If you are going to work a desk job, then nights and weekend exercise is not going to cover a horrible diet.

[kscaldef]

> At the true elite level Michael Phelps is fueled by 12,000 calorie a day diet, eating that much food just hard. Think 60 Twinkies a day plus a 3000 calorie diet.

Even at much less intense levels, it's challenging to eat as much as necessary to maintain weight if you have a healthy diet. When I was training 100 miles a week (not all that much for a serious cyclist) I ate around 3300 calories a day. If my diet included stuff like Big Macs and triple mochas with a muffin, that would be easy. But if you aren't in the habit of eating lots of processed and fast foods, it's actually quick a bit of work to eat that much.