MelissaTal

Well, if it gets down to it, if he truly doesn't care, then I don't think you should stress about it. It's up to the person alone to motivate themselves and choose what they want to shoot for/accomplish in life. If he's fine with who he is right now, then just leave it be. But, if you notice that it's causing him to act depressed, angry, frustrated etc. Then by all means, do what you can to motivate him.
On the other hand I admire your passion to care about someone else like that, never lose that quality.

lol cute lil sig

Well, "fat" is really hard to define, because if you don't get activity you have low amounts of HDL cholesterol which is not very healthy. Fat with higher amounts of HDL cholesterol is healthy. It's this reason alone that girls and guys who are 10-20 pounds underweight still think they're overweight because their fat has a disgusting quality to it. As for blatantly telling him too loose weight, it's kind of harsh, but sometimes people need the push to motivate themselves. Get the sense of proving someone else wrong.
He doesn't need to play a sport to tone his body up. A balance of both cardio, stretching, and a little weight training can go a LONG way for health. Combination of all those increases the effeciency of your heart by 3 times than somebody who does none of that. Lowers your resting heart rate. Increases the rate at which blood pumps around your body and also increases your bone density. (The list can go on forever)

And you can't honestly tell how much he REALLY smokes, unless you can monitor him all day. His body won't be able to physically and mentally handle the strain of getting back in shape if his lung capacity is significantly reduced by smoking. Even worse, you need to dedicate yourself to eating healthy, and learning about protein, complex carbs, fibre, etc etc to properly fuel your body.
Regarding the puppy fat thing, the kids I cycle and run with (15-16) have nowhere near any baby fat left, pretty much toned beasts.

Ouch, =/ that's a lot of things to factor into his health. It'd be even worse if he got any lack of sleep on top of that, I don't think you should encourage any of the behavior if it negatively affects him. Talk with him, be blunt about it. Or maybe try to get him into ANY type of hobby? <3

and btw, just because somebody doesn't "look" fat, doesn't mean they're healthy. He smokes as well right? doesn't get activity, and eats unhealthy right...?

ello ello!