Oil and salt are both nutrients needed by human body. If the intake is insufficient for a long time, it will definitely affect the normal operation of the human body. Therefore, proper intake of these nutrients is beneficial to health. Salt should not exceed 6 grams per day, and oil should not exceed 25 grams per day. Moreover, the dietary requirements for muscle gain and fat loss are different. Reducing fat means that the daily calorie intake is lower than the consumption, and at the same time, some muscles will be lost. Muscle gain means that the daily intake of calories is higher than the consumption. Although it is not impossible, it is very difficult to do both at the same time, which requires very professional knowledge of bodybuilding, muscle gain and muscle loss. Therefore, if you are not sure, it is best to reduce fat and gain muscle respectively.