I’m very conscious about trying to watch my manners on this forum and I don’t want to be a thread hijacker, though I feel obliged to correct myself.
Firstly having read and re-read the best document I can find describing the processes that lead to insulin resistance and then on to T2 diabetes I have to admit I was wrong – being fat does not cause insulin resistance in any way. Fat does play a big role in several steps in the cascade of problems that leads to a fatty liver, which is the most easily observed marker of the most common pathway to T2 diabetes. However, the problem appears to be triggered by high, rapid calorie intake, not being fat. Plenty of obese people, maybe a third, managed to put on their weight, presumably slowly and steadily, without triggering any easily observable state of insulin resistance.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4587882/
The same document illustrates that, to the best of my understanding, there are indeed unhealthy places to store body fat but it’s perhaps not so much about a specific area of the body such as under the skin. Healthy adipose (fat cell) tissue located (perhaps) anywhere in the body may be a good and healthy place, up to a point. Fat cells can accommodate the body’s need to store energy as needed, however if energy storage is too rapid individual fat cells can expand too far too quickly and become inflamed, insulin resistant and leaky. If this occurs on a large scale leaky fat cells raise levels of free fatty acids in the blood which are then taken up by tissues that are absolutely not good places to store fat, such as liver and muscle tissue. These tissues then become insulin resistant and the cascade of problems that can lead to T2 diabetes progresses.
Fat storage in healthy adipose tissue under the skin appears to be generally good and fine from a metabolic perspective. Fat storage in healthy visceral adipose tissue, between the organs rather than inside organ tissue, does have known health implications if present in large amounts, for example in kidney disease:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8014972/
However, I can’t find a single document that seems to prove that healthy, non-inflamed, visceral adipose tissue fat is a cause of, not a symptom of, obesity or insulin resistance. Fat storage in other kinds of tissues (ectopic fat) is varying levels of bad, depending on the tissue or organ and absolutely causes insulin resistance. I’m uncertain if fat cell inflammation due to overly rapid energy storage in adipose tissue is synonymous with damage. Does the inflammation subside if the body is in a period of significant calorie deficit? Or is an inflamed fat cell permanently leaky?
Also I’d like to thank the posters that wrote about visceral fat in other mammals. This led me to do some reading and I discovered that humans are very much unique as regards where and how we store our fat and how much of it we store. Interesting reading.
https://www.genengnews.com/news/how-the-naked-ape-became-the-fat-ape/