I’ve seen this exact same thing, luckily only on other people so far. But it’s common to see the midsection thickness on most men over 50. Usually, I’d say it’s visceral fat accumulation. Besides the usual advice (don’t get fat), I think DHA is the most promising fix:
From the linked article: “Early animal studies showed that DHA supplementation reduces visceral fat accumulation, even when the animals are on high-fat diets. Newer human studies show that DHA-rich fish oil reduces visceral fat and waist circumference in overweight folks with metabolic syndrome. In another randomized trial, DHA supplementation improved lipid profiles and reduced markers of visceral fat in obese individuals with non-alcoholic fatty liver disease (NAFLD).”
Visceral fat is associated with muscle loss and testosterone decline, so make sure your levels are in the mid-normal range at least: TRT if you’re not already on it.
Insulin resistance and cortisol plays their parts, too, and EPA/DHA would help there too. And I’m betting heavier alcohol usage is common with most of these guys. I’d kill the sugar and excess booze, if applicable.