Research shows that the best predictor for one’s own behaviour is to watch what other do. This means that what you do also determines what others do. Even – as further research shows – to the degree that when you gain weight, others will, too. So when your spouse blames you for making them gain weight, they might actually be right. If you want to change the world, the most effective thing you can do is to change your own behaviour.
Important note: it’s not just tell, it’s not show don’t tell, but show and tell. Mere talking leads to what we find today: a lot of empty words without action, hypocrites. Keeping your actions to yourself misses the opportunity that others can copy. Talking about what you do not only allows those in your immediate surroundings to be led by example, but also those friendly other people on the internet.