After reading Good Calorie, Bad Calorie by Gary Taubes, I couldn't understand why people were still convinced that the calories in-calories out idea was important. It's especially surprising when I hear low-carb folks urging us that calories still count.
I have personal experience that says calories aren't really that important. When I was a low calorie vegetarian, I was eating about 1700 calories a day, and gaining weight. Once I switched over to being a low carb meat eater, my calories went up to 2300 or so a day, and I lost weight!
The same is true for Chad. He used to eat about 2100 calories a day, and was slowly gaining weight. But after switching to about 2500 low carb calories, he's lost about 20 pounds while also putting on muscle. Are you sure calories count?
A new and really fun example of how silly the calories in-calories out idea is, is Sam Feltham, from Smash the Fat. He's in the middle of a 21 day experiment where he's purposely eating 5000 calories a day (a 2000 calorie a day surplus for him) to see exactly what it will do to his body. It's important to note that the food he's eating is low-carb, paleo fare.
Since I'm on vacation, gallivanting across the countryside with Chad and his family, I'm writing this about a week before it posts. But so far (day 9), Sam has actually lost two centimeters around his waist, and hasn't gained a thing. This might change by the time he's finished, but something tells me he won't come even close to the weight CICA says he should gain. A quick calculation shows me that CICA says he should gain about 12 pounds by the end of the experiment. But he's half way through, and he hasn't gained anything!
Maybe it's true that some people need to cut their calories in order to lose weight. After all, everyone is different. But to say that everyone needs to cut calories is, I believe, harmful to most people. You shouldn't feel hungry, even if you're trying to lose weight. A little hunger before a meal is alright, but constant hunger is a sign of problems. And unfortunately, for most people, cutting calories makes you pretty hungry. So then your body, being smarter than you, turns your metabolism down a notch, and it becomes harder to lose the weight. I've been there. I also know what it's like to be exhausted all the time while cutting calories.
If you want to watch Sam Feltham's experiment, he has daily youtube videos, and also posts updates on twitter frequently.