...One thought. My pilot's license requires a medical card signed by an FAA certified physician. That might not be a bad idea for us older divers. I certainly wouldn't object.
The FAA (USA) and the DOT (USA) required a medical certificate from a specially certified examiner for the reasons of PUBLIC SAFETY. Should your pilot or truck driver become incapacitated in flight or on the road quite a few innocent bystanders stand in harms way. In the case of the incapacitated diver this just isn't the case. Yes the buddy(ies) may incur increased risk, and so too can the boat crews - but neither group are innocent bystanders.
If you fly only yourself (Sports and Recreational pilots license) the FAA lets you self certify your health.
Some of you would cringe at diving with some of the people I have to certify as fit to drive commercially (I'm a certified DOT examiner) since they meet the standards, but I wouldn't call them healthy.
You can't stop getting older. You can control calorie intake.
Choices.
If controlling body weight were as simple as "exercise more, eat less" then I would be out of one of my jobs. Excess body fat is a multifactorial chronic medical condition, very much akin to elevated cholesterol, elevated blood pressure, and elevated blood sugar. It has to be managed continuously to decrease the potentially serious health risks these all entail. Managing any of these chronic conditions takes focus, effort, support, sometimes medications, and above all
taking ownership of the condition and not letting it OWN you. You also can't tell someone has most of these conditions just by looking at them, but you can see their size - however that doesn't tell you if they just lost 100# and are still losing more.
The more "rules" we put in place to protect us from ourselves, the less freedom we all have and the more liability those who provide us goods and services have to deal with. Some "rules" are needed for the greater good (IMHO pilot and commercial driver physicals, however porous, are examples), but a diver's physical as a
requirement for recreational diving (not talking training) isn't among one I feel is needed.