My advice falls into two camps:

1. Diet
2. Exercise

As mlc says, it's perfectly possible to be healthy without being skinny, just as it's possible to be skinny and unhealthy.

Diet

Obviously you need to be a bit careful if you have a history of cardiac disease in your family. However, I would emphatically *not* recommend low fat everything. The cholesterol-heart hypothesis is not as solid or simple as it is made out in the media or by many doctors. I would recommend doing your own research on the matter, but you might want to start here.

So, it's important that you eat well - meat, fish, fats (not industrial oils like vegetable oil), vegetables, fruits and nuts (but don't go crazy on these). As mlc indicates, the nutrient profiles (and nutrient bioavailability) of vegetables change with cooking, but not necessarily negatively. If you're eating lots of food I wouldn't go out of your way to eat loads of "superfoods" as so long as you avoid crap you'll be getting a good amount of nutrients anyway. Superfoods tend to be expensive and a bit overhyped, but if you like them then fair enough.

In a nutshell - avoid processed food.

Exercise

Exercise is the key to health at a higher weight. It's not so much about jogging, though. To be honest, I'd never recommend running to people who are overweight, as you'll likely get injured unless you're very strong and have good technique. If you're serious about your health, make sure to build movement into your everyday life - walk lots, cycle instead of drive etc.

The other I'd suggest is do weights. Not silly bicep curls with tiny weights so you don't get "too bulky", but proper functional compound movements like squats, deadlifts, lunges, press-ups, pull-ups etc. Higher lean mass (i.e. muscle) has been shown to correlate with greater health and life expectancy. It will also help maintain or enhance your quality of life.

In a nutshell - move lots, and lift heavy stuff once or twice a week.

Water polo is knackering! Last time I played it was back at uni, and I was exhausted. I was also terrifically fit (rowing - training 10 times a week).

Strength training, walking... but really just anything you enjoy. No reason why you shouldn't play basketball if you're bigger, and that (can) involve a lot of running and jumping.

I wouldn't recommend distance running though - I'm of the opinion that to run properly requires a good strength to weight ratio if you're not going to get injuries.

Yeah, unless your metabolism is damaged your body will defend its weight, whether you're trying to gain or lose.

Eating more won't slow your metabolism down (well, depending on what you're eating!). If anything it will speed it up. Are you trying to get fatter or more muscular?

I've got two books on the go:

- Prosperity without growth, by Tim Jackson.

- The adventures of Huckleberry Finn, by Mark Twain.

I like to alternate between fiction and non-fiction, and am trying to read more classic novels which shamefully I have neglected.

I think that's an interesting idea, but I have to disagree that feederism is a private fetish. I'm sure it is for some, but I don't think that's the case for many others.

Feederism doesn't just exist inside relationships. In fact, I imagine that for many it only exists outside of them! I know that I first came to explore the fetish through realising that seeing women gain weight, usually celebrities or pics of random girls on the internet, turned me on. Equally, many feedees seem to find their fetish quite independently of relationships.

And in other ways, feederism is a peculiarly public fetish. Most other fetishes are confined to the bedroom, but weight gain is lived out every second of every day. Sure, people might not know that someone is gaining weight on purpose, but the effect is still there for all too see. I think this is why there is societal pressure, not because feederism is private but because it is potentially public.

I think it's important to distinguish between fat admiration and feederism. I'm sure that fat admiration will become more and more accepted... in many ways it's already pretty mainstream. There are songs about it, and it's generally acceptable for a guy to "dig fat chicks" even if he might get a bit of stick for it. I imagine it's probably harder being fat, but then increasingly you'd have the weight of numbers on your side (pun clearly intended!).

Feederism is altogether different, though. Some fetishes are always likely to be seen as rather dark, and I suspect feederism will fall in this category. A fetish doesn't have to be understood to be accepted - I don't get foot fetishes, for example - but it does need to be seen as benign. Feederism is seen as inherently destructive - after all, fat is bad for your health, apparently.

Yes, there are misconceptions of control, manipulation and mental illness which cloud the matter too. But ultimately I think the fact that gaining weight can be bad for health, particularly when combined with the common preference for extreme unfitness, will keep feederism from ever being truly accepted. Heck, I have the fetish and still struggle with this issue, so heaven knows how someone who can't experience it will come to accept it.

Yeah, people react to stress in different ways - some point on weight, some lose it... and some just stay the same! I wouldn't worry too much either way - just as others desperately want to be thinner so go on counter-productive diets, so you want to be fatter... but I think the most important thing is to be comfortable with how you are.

That said, have you considered resistance training? Given your height, weight and relatively high body fat percentage, I deduce that you must have very little muscle. Lifting some heavy weights (well, heavy eventually!) would put bulk on you but so long as you keep the body fat you'll likely look chubby.

It will likely stimulate your appetite, and there'd be potential health and quality of life benefits too.

I suspect the problem often lies in the fact that we're conditioned to think that people are scared of becoming fat. We worry that calling someone fat will cause that person to think 'oh, you're right, I am - I better lose some weight' even though that makes no sense if that person is deliberately trying to get fatter.