If you are looking for a refreshing read on food and health, try Food Rules by Michael Pollan. Packed with short but sensible "rules" that are often thought-provoking, the book encourages people to 'eat food, not too much, mostly plants.'
You can see a few of the rules here as a taster, and the volume itself is slim enough to stash in a handbag or under the coffee table for quick moments of motivation.