Well if you are morbidly obese it affects your blood pressure, breathing, heart, digestion, hormonal balance, can cause Type 2 diabetes, and affects the musculoskeletal system, stamina, sleep and general fatigue.
Oh yeah and depression. There’s not much it doesn’t affect.
I’m not talking about anyone who is morbidly obese but for some doctors extra weight, no matter how small, is the blanket reason for any ailment.
I developed the average late life belly roll after abdominal surgery a few years back. That was followed a few years later by a diagnosis of type2 insulin resistant diabetes which is very low level. No need for insulin and continued exercise and watching diet made no difference. That it wasn’t my belly roll was confirmed for me when several skinny as a rail acquaintences of mine developed the same problem, all of us in our late 50s, early 60s and all in good shape physically.
My doctors all have said, nothing to do with any body fat, just getting older.