I was reading some stuff about nutrition on the Prostate Cancer Foundation site recently - pcf.org
I was struck by the following:
"This excess fat, especially the fat around the middle of your body, has been associated with an increased risk of many diseases, including prostate cancer. ..... Body fat is actually an organ with functions. It secretes hormones and specialised proteins that can increase inflammation and oxidation in the cells of your body - two natural processes that are strong contributors to the development and progression of prostate cancer."
Whilst it's easy to think of weight loss in terms of looking good and fitting into such and such size jeans, there can be a very serious side to weight loss and good nutrition, too.
Good luck with your weight loss journeys, whatever your reason is for doing it.