This guide is extracted from Tom Venuto book: Burn the fat feed the muscle Hope will help everybody to optimize his diet Lean mass stays the same and body fat decreases Fantastic! Your diet and exercise program is working as planned and you're on your way to reaching your goal. Don't change anything. Keep up the good work! Lean mass remains same and body fat remains same Nothing is happening either way; you're at a standstill and you need to make some adjustments to get yourself moving again. First, increase your cardiovascular activity level. You can increase the number of days per week as well as how long you are exercising at each session. If you don't lose body fat within the next week, then you can reduce your caloric intake systematically by 100-200 calories at a time, provided you do not drop below your maximum allowable calorie deficit. Keep your nutrient ratios the same unless you've been stuck for more than two weeks. If you've been stuck more than two weeks, you might want to experiment with a moderate or low carbohydrate diet and or zig-zag carbohydrate cycling. Lean mass stays the same and body fat increases You're in a calorie surplus. You're eating more calories than you're burning and storing it as fat. First increase the frequency and duration of cardiovascular exercise. Then recheck your body fat in one week. If it hasn't decreased, reduce your caloric intake by 100-200 calories at a time, provided you do not drop below your maximum allowable calorie deficit. Keep your nutrient ratios the same. Lean mass decreases and body fat decreases You are losing body fat which is good, but you've also lost some lean mass, which is not good. A small loss in lean mass (a few tenths of a pound) is nothing to worry about. If this is the first time you've lost LBM, don't panic because some of the LBM is water weight. If this is a recurring pattern and you've been losing LBM every week for more than two weeks straight, you're losing muscle tissue. You need to eat more, at least temporarily. Increase your caloric intake by 100-200 calories to stimulate your metabolism, while continuing with your current exercise program. Keep your nutrient ratios the same. Lean mass decreases and body fat stays the same or increases When you lose LBM and your body fat does not decrease at all, this usually means your metabolism has slowed down and you are burning up muscle for energy; you are not in fat burning mode. This often occurs when you skip meals. Losing lean mass means that you need to eat more to stimulate your metabolism. Don't be afraid to eat, and keep up your meal frequency to five or six times per day. Remember that it's better to burn the fat off rather than starve it off. Keep your calories as high as possible while using exercise to burn off the fat. Severely restricting your calories below the recommended levels will always result in a loss of muscle mass. Increase your caloric intake by 100-200 calories and maintain or slightly increase the amount of cardiovascular exercise you are doing. Make sure you're consistent with your weight training as well. Lean mass increases and body fat decreases This is very unlikely to happen, except for genetically gifted individuals (the pure mesomorph) and sometimes for ectomorphs who have highly efficient metabolisms. If it does happen, terrific! You are leaner and more muscular! Don't change anything. Keep up the good work, you're on your way to reaching your goal. Lean mass increases and body fat stays the same Good job, you've gained muscle without gaining fat! This is the ideal outcome for a muscle-gaining program. If you also want to reduce your body fat percentage, you'll need a greater calorie deficit, which you can accomplish by increasing your cardio while remaining at your current caloric intake. Lean mass increases and body fat increases You gained muscle, which is good, but you also gained fat, which is not good. You are in a substantial calorie surplus. Some bodybuilders do this habitually in their off season - it's called "bulking up". If you want to stay lean and avoid the "bulked up" look, you need to increase the amount of cardiovascular exercise you are doing. You should also make sure you're being strict enough on your diet. Keep your diet "clean" and free of high fat or high sugar junk foods. Recheck your body fat in one week. If you still continue to gain fat, then you need to decrease your caloric intake.