The best way to help others in my experiance is to become the example and let them come to you if they want help.
The truth is, giving advice to people who don't really want it will only make them dig their heels in and resist you even more.
To really help people, they need a change of paradigm, which they can only do themselves. You setting an example that shows how much better off they could be, will help that happen.
Also, you need to come to terms with the fact that you can't 'save' everyone. I've tried to help my parents with their terrible diet and declining health for years...
Hope that helps
