Genetics are one of the most important factors in building muscle mass. There is not much you can change about your interior perfect amino reviews genetics that shape your body, but you can improve the way you look by becoming more tone. Some of us just do not have the bodies that will have large muscles, so accept that and strive for better tone.
You need to take in more calories when trying to grow muscle. Eat an additional 3500 calories per week, which will be enough to put on about a pound. Look into ways you can take in more calories. If you don't see any changes in your weight within two weeks, try consuming an even higher amount of calories.