An ectomorph would be tall and thin, with a narrow body, thin arms and legs, little body fat, wiry muscles and a big appetite but never seemed to gain a pound (like the one you hate at work). Ectomorphs often crave stimulants such as caffeine, nicotine and artificial sweeteners. They often have problems with unstable blood sugar levels, which can cause fatigue and cravings for sugar and stimulants. An example of an ectomorphic would be Barack Obama, Lance Armstrong and Dave Chappelle. In general, ectomorphs rank high on aerobic endurance, flexibility and agility.
Most People are not of just one body type. People tend to posses a combination of two or have characteristics of all three body types. If you are an endomorph, with proper training, you can take on characteristics of a mesomorph. If an active ectomorph takes on a light desk job and become inactive, he or she can start to look like an endomorph.