There are a lot of aspects to living a healthy life besides just getting your weight down to what it should be. Here is a nice informative infographic with very useful suggestions.
Regarding the second point – Sitting down all day, I have a Page on The Dangers of Too Much Sitting. Check it out for more info.
You can also look into my Page – How Important is a Good Night’s Sleep?
I also have a Page on the tenth point – Smoking. Check out – How Many Ways Does Smoking Harm You?