We do differ by skin type or by skin colour, but we also differ by body type. The things which make us different from others is your lifestyle, genetics, history and training style. Basically there are three human body types: ectomorph, mesomorph and endomorph.
Ectomorphs tend to be thin and they struggle to gain weight, basically they are “hard gainers”. Even if the eat piles of food they tend to remain same. They do have long limbs and lean body. Even if they manage to put on weight they look skinny. As the rate of metabolism is high hence they burn the calories at a faster rate. Hence it becomes difficult for them to put on weight. But this doesn’t mean they will stay lean for their entire life. They too can put a significant amount of weight, but if they want to do so they have to eat a lot like never before. If they want to put on weight then the most important thing is to track down the calories and calculate daily calorie demand. They need to follow a diet which contains well balanced carbs, and protein.
Mesomorphs have an athletic body, they tend to have well defined muscles, wide shoulders, narrow waist and relatively thin joints. They have a natural tendency to stay fit and muscular. Their body is more responsive to the exercise and the diets, they can cut body fat and can regain their shape easily. Their metabolism is well balanced and they can gain muscles with comparative ease.
Endomorphs tend to have a thick rib-cage, wide waist and short limbs. They tend to gain weight easily, but most of it is Fat. The metabolism is much slower as compared to the other two types, hence their body stores the extra calories in the form of fat. They do have difficulty in managing their weight. Adding muscles become very difficult in this case. If they want to lean out then they need to increase the amount of protein in their diet as it may help to increase lean muscles mass and trim excessive body fat.