[ugh]

It is more fattening if it has more calories.

#1 large you say? McDonald’s website tells me that if you buy that from them (Big Mac, large fries, ketchup, large Cola) you are looking at 1200 calories. I find it hard to imagine that any two of the photographed products on the linked website would have less calories. One Snickers bar – one, not in any way fried – has about 300 calories. A Big Mac has about 500. A large Cola (0.5 l) has 250. A nice portion of pasta with something as innocuous as tomato sauce can get you up to 500 calories.

There is nothing particularly evil about fast food. If that one menu is pretty much the only thing you eat on a day you can easily lose weight. It’s just that something with a high calorie density makes it very hard for you to control your portions. My suspicion is that the submission’s food all have a quite high calorie density, higher than even most fast food.

The worst offender on the McDonald’s menu are pretty much the fries. A Big Mac is relativly harmless because in addition to the high calorie density meat and sauce you also get the bun and even some salad. If you drink water instead of Coke you even push the calories below 1000 which means that you could easily eat two of those menus on a day without gaining weight.

[beagle3]

> It is more fattening if it has more calories.

That's known not to be true. See http://www.sethroberts.net/about/whatmakesfoodfattening.pdf ; If this theory is true, then the fact that McD tastes the same every time makes it more fattening independently of calories.

Even if you disagree with this premise (it IS controversial), the research he references (Michel Cabanac, Robert Israel) is an accepted and very strong indication that in fact the caloric content is NOT what makes food fattening.

[ugh]

I’m not sure what you want to tell me. All that might be true but if I’m parsing it correctly it doesn’t mean that you will gain weight if you eat for example 1000 calories of anything per day. You will still lose weight. And you won’t if you eat double or more than that.

[beagle3]

No, you aren't parsing this correctly.

Cabanac has reproducible research that shows people losing weight on (IIRC) 2500 calories per day and NO physical activity whatsoever, because they were bed-ridden.

MGU had a research once that had people gaining weight on 1500 calories/day and losing weight on 3000 calories/day with comparable physical activity (this one included running, etc.)

The "calories in / calories out" argument is very far from science. If you trace its origins, you'll see it's not much more than a folk tale. It's about as accurate as "eat less to lose weight" in terms of being predictive.

Gary Taubes "Good Calories, Bad Calories" has all the explanations and references you could need, if that interests you.