The research: Learning improves when you learn something with the intention of teaching what you learn to others, even fictitious others (in the professional journal, Contemporary Educational Psychology 2016 in press).
The rationale: If you expect to teach what you learn, you might very well monitor the quality of your understanding more, think more deeply about what you’re learning, process what you’re learning more actively, fill in gaps in your knowledge, and develop corollaries.
The application: What would happen do you think if you tried to teach others how to get themselves to do what it takes to lose weight? As a result of intending to teach what you learn, would you be more aware of, perhaps even more able to do what it takes to get yourself to lose weight?
The invitation: Why don’t you try this and find out.