Depending on your goals, various types of carbs, proteins and fats matter. Basically its BMR (basal metabolic rate) times your activity factor to determine the amount of calories you need in a certain day, TEE (total energy expenditure). Simple carbs and complex carbs is all dependent on your goals, if you want to lose weight take your TEE - 500 kcals and your will lose a pound a week of real weight. If you dont trust the Harris Benedict Formula try out the other formulas like Mifflin St. Jeor to figure out your caloric needs. Usual macro nutrient breakdown is 55% from carbs, 20-30% from fat, and the rest from protein. People may rave about a certain diet that works but in the end its about caloric intake and output, whether you have a low carb high protein diet or high fat high protein diet, as long as the calories are the same you will see the same weight loss. I have researched on various zone diets for school and all has the same results. If i could give any advice stay way from high sugar foods, anything with high fructose corn syrup. look for whole grains and items with dietary fiber, read the nutrition label!!! compare the amount of carbs to the amount of sugar, and fiber that you are getting. that should give you an idea about what kind of carbs you are consuming.
