Macronutrients: a type of food (e.g. fat, protein, carbohydrate) required in large amounts in the diet.
There are three types of macronutrients. Carbohydrates, lipids, and proteins. This man mainly eats carbohydrates, which is problematic because while they are an amazing energy source, too much will continue to build up and be stored as fat without a proper exercise to get rid of the energy. One way to improve his diet would be to reduce his carbohydrates intake by half, and double his vegetable intake.