Just came across this article: The calorie is broken. It suggests that the old “calories in, calories out” rule doesn't work for weightloss. Don’t bother clicking the link; even though it is presented as “news,” nothing in it is new!
To summarise:
Calories in food are often measured inaccurately. Sometimes on purpose (oh marketing, how you deceive!), sometimes by accident or due to ineffective measuring methods.
There’s also the issue of serving size. After visiting over 40 US chain restaurants, including Olive Garden, Outback Steak House and PF Chang’s China Bistro, Susan Roberts of Tufts University’s nutrition research center and colleagues discovered that a dish listed as having, say, 500 calories could contain 800 instead. The difference could easily have been caused, says Roberts, by local chefs heaping on extra french fries or pouring a dollop more sauce. It would be almost impossible for a calorie-counting dieter to accurately estimate their intake given this kind of variation.
Obvious solution here—if you are trying to get healthy, why on earth are you going to chain restaurants and eating french fries? Anyone with a grain of sense will know that is not something you should do on a regular basis. In addition, if you are hoping to lose weight, you need a fairly significant difference between calories in and calories out—500 fewer calories every day will result in about 1 lb of weight loss weekly. If you are aiming to eat 1600 calories when you expend 2100, but accidentally eat 1900, you won't lose weight as quickly but you should make some progress (or at least stop gaining). When I track my intake/output, I usually try to err on the side of caution. Is that banana “small” or “medium”? I will select “medium” to be on the safe side.
Main point though, is that this doesn’t disprove calories in/calories out, it just demonstrates that—as with everything—accuracy counts.
Next issue: people burn calories at different rates. This comes as a surprise to no one. A variety of factors including health issues can affect how people process food. This is why tracking systems like fitday offer a choice of different ways to calculate your baseline metabolic rate.
Try one. Does it seem to fit? If yes, great. If not, try another. Or input a custom baseline if that’s what works.
Again, this doesn’t disprove calories in/calories out, it's just another demonstration of the need for accuracy.
And there have been many, many studies showing that people kid themselves about how much they actually eat and how much they actually exercise.
The article then goes on to describe a “new” diet based on satiety. In the past this has been sold as a diet of “nutrient dense” foods. I dimly remember a diet book from the 1970s comparing the calories and nutrients in a cubic inch of brie to a cubic inch of shrimp, and obviously suggesting you go for the shrimp! This is not new.
All of this silliness reminds me of someone I used to know who was obsessed with his physique. He was terrified of consuming any amount of fat. Instead, he would opt for things like a butter substitute which was some sort of viscous yellow liquid in a spray bottle (I shudder to think what the ingredients might be) and would eat marshmallows by the bucketload—because they are fat free! or the various people who have been “shocked” to discover that vitaminwater is no different from pop, nutrition-wise, or that nutella is actually more candy than health food.
It always comes back to the same thing. Eat what your grandmother ate. In moderation. use common sense. Looking for some extreme rule or fad diet to follow—or an article to excuse you for overeating at chain restaurants—is an exercise in delusion.