healthy living?

I went to the docs last week for a medical. He said I'd put on 12kgs(nearly 2 stone) in
the last year! He then sent me for a blood test. That came back today, and my cholesterol is too high-everything else is fine. If I stay here, and keep on putting 2 stone on every year-that can't be good. It's official- the Uk is killing me! i have had 3 pints in the pub in the last 6 months.I do drink 2-3 pints of milk a day though ,and 1 can of coke. I don't eat fried food, I only have chips once a fortnight. I sit on my arse all day though, and my walking has gone down to nearly nil. I need to be teaching and walking in the hills of Hong Kong or streets of Kowloon, or even dancing in the streets of Wanchai. The funny thing is, is that I did lose loads of weight when I first went to Hong-Kong. Swings and roundabouts mate, swings and roundabouts..
How do you lessen cholesterol?