Calories and Satiety
This post ran long, so here's the tl;dr:
(1) A Calorie Is A Calorie: You gain or lose based on how many calories you consume minus how many you use.
(2) Satiety Matters: It's easier to be satisfied with fewer calories of some foods (ex., vegetables) than others (ex., potato chips).
A Calorie Is A Calorie
According to this study , Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates, the answer is yes.
The study enlisted 800 people to go on various kinds of diets and tracked them for two years. Their conclusion: "Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize."
The idea is often expressed as "a calorie is a calorie": For the purpose of gaining or losing weight what matters is calories consumed minus calories used. Your orange juice calories will make you fat just like your cheeseburger or salmon calories will.
Satiety Matters
A related question that often comes up when trying to lose weight is, "If I'm going to limit myself to a certain number of calories per day, what foods should I eat to make that as easy as possible (i.e., to keep me from getting too hungry)?" This is the question of satiety.
A recent study, , Changes in Diet and Lifestyle and Long- Term Weight Gain in Women and Men, took data from 120,000 (yes, one-hundred-twenty thousand!) U.S. men and woman over a period of 20 years. The subjects were just living normally. They were not given any instructions on how to eat or exercise.
The study looked at how various factors were correlated to changes in the subjects' weight. Figure 1 in the paper shows that consumption of some foods is associated weight gain and some with weight loss.
Gain: potato chips, fries, processed meat, red meat, butter
Lose: yogurt, fruit, whole grains, nuts, vegetables
There was no controlling for total calorie intake. They just observed that when people ate more of the foods on the "Gain" list they gained weight and when they ate more of the foods on the "Lose" list they lost weight.
They hypothesize (consistently with other studies) that "consumption of starches and refined grains may be less satiating, increasing subsequent hunger signals and total caloric intake". Also, they say "Higher fiber content and slower digestion of these foods would augment satiety, and their increased consumption would also displace other, more highly processed foods in the diet, providing plausible biologic mechanisms whereby persons who eat more fruits, nuts, vegetables, and whole grains would gain less weight over time."
Dave
