Aside from burning off more calories through physical activity, the only other control you have over calories lies in the food you eat and the beverages you drink.
Amazingly, most of the thousands of books and programs on weight loss do a very good job of avoiding teaching you anything useful about calories. Most don’t address the subject at all. Worse yet, some tell you that calories don’t matter… that some special combination of foods, nutrients, etc., is the secret to weight loss. Understanding the calories in food however, is fundamental to weight management.
Here's just one example of why understanding the calories in food helps one manage their weight. Several years ago when out for dinner at a national steakhouse chain, I ordered the chocolate cake dessert to go. I wanted to know how much it weighed--to determine the calorie content, and share data with my weight loss patients. It was a big piece of cake, and it was dense. No one in the two night classes I was teaching came anywhere close to guessing how much it weighed. It weighed an even pound! The calories in that slice of cake were equivalent to the entire days' calorie needs for a (sedentary) 145-pound woman!
*Cake is ~[100 calories/oz.] x 16 oz. = 1,600 calories