I lost 23 pounds last Spring just keeping daily carbohydrates under 20 grams per day. Part of me says that this is just another variation on calorie counting - but it does force me to emphasize an intake of protein and greens which I think is the smart approach.
Unless you went on a diet that restricted calories and were hungry - you'd know this - you likely didn't change your caloric count all that much but instead changed the makeup of those calories. This changed your insulin response and instead of building fat, your calories went more towards muscle cells for energy.
