What is it that causes some people to have higher levels of central adiposity compared to others?
It’s often thrown around that “stress” or higher cortisol can cause more fat in the abdomen, but outside of cushing’s syndrome, is this plausible?
I know certain phenotypes such as South Asians are more likely to hold fat centrally, is there anything specifically that could explain this? And the within phenotype variance?
Individuals have many differences that affect weight management, body composition, body fat distribution, and so on.
Overwhelmingly, genetics are the biggest driver of these differences. To your specific example in individuals of South Asian descent, different ethnicities tend to have different average skeletal size related to genetics. Muscle mass carrying capacity scales with skeletal size. For a given weight and height, individuals with smaller skeletons will tend to carry more fat and less muscle. Where that’s distributed has is also different amongst sexes, with multiple genetic inputs here.
Going further into specific genes, pleiotropy, and so on is beyond the scope of a forum reply. However, I view genetics as the main driver of apparent differences, though there are other inputs too.
thank you, so lifestyle factors (diet, sleep, exercise, stress management) have little impact on body fat distribution specifically, just total body fat?
We can’t really change body fat distribution tendencies, no. Again, this is speaking very generally and ignoring some medical conditions that would generate a different answer.
Was there any rationale for “cortisol” causing bodyfat storage around the “middle” in men? That’s been circulating for as long as I can remember.
From extremely high levels of cortisol like Cushing’s or prolonged steroid medication use, yes. It is highly unlikely to occur from life related stress though.