Endomorph is the naturally round individual, this is a person who is extremely insulin sensitive and whenever they eat foods that even moderately affect their blood sugar, it stores as fat in their bodies. Complete endomorphs typically have fat cells located all around their bodies: head, chest, stomach, hips, and legs. This is the type of person that can weigh in the 300’s if they don’t watch what their eating and workout.
Ectomorph is the complete opposite of endomorph, this person is stick skinny with little to no fat anywhere on their body. The complete ectomorph is insulin resistant, so every time they eat anything that even spikes their blood sugar it goes no where. It doesn’t hit their fat cells nor muscle cells. This person will stay skinny until either they eat a surplus of macros or calories, or as they age their metabolism slows down.
Mesomorph is the genetically blessed individual, this person is what we may describe as a meat head. They’re just muscular all over their bodies. Their muscle cells are sensitive to insulin spikes, so whenever they eat anything that raises their blood sugar then it goes to their muscle cells.
To conclude (most people) are a combination of 2 or 3 and not proportionately equal. Meaning you could be 1/3 endomorph and 2/3 mesomorph, you would look muscularly fat. Some people say thick. Or you could be 1/3 Endomorph and 2/3 ectomorph, which you would look skinny fat. Whatever your genetic layout is, find it, research what foods affect your bodies in what ways so that you know what to eat and how to workout to get the body you want!