How people use their bodies is highly dependent on type. Obviously basic physiology is due to genetics and early nutrition, and no this has nothing to do with phrenology.
I and others have observed a few guidelines for body types, for which a few examples should make it obvious. INTP's are prone to ectomorphy - lean and slightly muscled. Is that surprising? No, INTP's are prone to sitting around thinking (Ti/Ne), and certainly are much less prone to say, hard physical activity. They also are sensitive to internal body states (Si) so are less prone to overheating, and less prone to eating at all actually.
Sensors tend toward two camps, endomorphy and/or mesomorphy. Endo is most common, as Sensors (especially Se dominants) enjoy food and company, so naturally they gain weight, especially as they age. Other, perhaps more health conscious Sensors will often combine overweight with a strong, muscled physique. How many guys have you seen with a muscled body with a big layer of fat over it? Quite frequent. Sensors are prone to make theory fit their desires, so it's common for these people to believe they can consume whatever they wish, and exercise will both make them healthy, and lose weight. No amount of evidence sways them from this opinion.
INF's are prone to being thin and "storky", and ENF's are prone to flabby excessive weight (ENFJ's in particular). Und so weite ...