BMI = 30. V.v. bad!

I'm overweight. I'm not sure whether I fall into the obese category, but I can't be far off. I've been fighting my weight for the last forty-odd years. I got married in my twenties, and gave up smoking shortly after. As a result of one - or possibly both - of these things, I started seriously putting on weight, and it's been an ongoing problem ever since. You name a diet and I've tried it, with little result. Mind you, as you must be tired of me telling you, I'm nearly 70 (just a few more weeks to go) and generally feel in pretty good health, so should I be bothered? My doctor tells me I'm a marginal type-2 diabetic, and that my weight is a factor in that, but again, I've nearly had my three-score years and ten, and my main priority now is to see out the time left to me in peace, quiet and comfort. I'm not a sweet, biscuit and cake man, so there's little in the rubbish food line I can cut down on, so doubtless I shall continue to fight my weight right up to the end.