You made that resolution to eat better, but sticking to it is easier said than done, especially when you’re craving just one more cookie. In her book, Stanford psychology instructor Kelly McGonigal tackles the hardest part of being on a diet — having the will power to say no to food. She teaches dieters how to control their impulses and understand the willpower instinct as a muscle that can be strengthened through training. The book is designed to be a personal experiment; each chapter has assignments that will help you to become a “willpower scientist” over 10 weeks. “These experiments are a great way to break out of a rut,” promises McGonigal. (Published by Avery)