If you are dieting just to lose weight you need to count calories. A certain amount of calories lost, like 3500 equal one pound. That’s pure math and that’s bottom line to control how much you weigh. Counting fat and carbs will help to ensure that the calories you are consuming are healthy for your body, however you could still lose weigh, being on a chocolate cake and banana split diet as long as you observed the right calorie count. Of course such a diet wouldn’t be healthy for you at all, but you would lose the weight.

Counting fat and carbs is good for a healthy well balanced diet, but let’s say you ate the right amount of fat and carb grams but went way over on protein and other things. You would likely be over calories for the day and not lose weight.

Bottom line is that you need to count everything if you want to be thin and healthy.