My Dad is overweight.

My eldest brother(+8 years) was overweight but lost a lot of weight on his own initiative but is falling back to his old habits although still excersising regularly.

My other brother (+2 years) does absolutely no excercise at all and is one of those naturally skinny types who is getting chubby and I can forsee a future with him ending up just like my dad.

My mum too has lost a lot of weight due to excercising but is still overweight and still eating hundreds of sugar filled products.

They're all addicted to sugar. I can have conversations with then where they agree theh need to lose weight and to eat only at the weekends etc, but they fall right back into it. They treat it like a game.

My main intention here is to try and prolong my dad's life but nobody else is helping me. In fact I had just hidden the dam sweets from the weekend and found my brother ravaging through the cupboard and then told me "I'll give them to dad, he doesn't want to lose weight".

I know he just said that out of rage in his 1 hour sugar deprived hell.

My family is not perfect in many ways and the fact that a 19 year-old has to do this to his family is pathetic (which is probably why I'm here) but I'm luckier and more greatful than most and I'm dam sure not going to let them kill them selves.

I've just written these paragraphs out of pure rage and helplessness. I'm also probably going about this in the complete wrong way, how can I help them? I appreciate all responses.