A U.S.-based cross-sectional study in men aged >45 years found:

Forty percent of obese nondiabetic men and 50% of obese diabetic men aged ≥45 years have subnormal free testosterone concentrations.

We’ve talked about this before.  Low testosterone makes it harder to make muscle, which makes it harder to burn calories and to avoid diabetes…  A vicious cycle.

Obesity, high blood pressure, and diabetes damage blood vessels.  Weight loss and exercise (including resistance training) can help reverse this, potentially restoring libido and sexual function.