Day 28: Have a Couple of Drinks

Have a couple of drinks, then cut yourself off. Not only will doing so help you avoid regrets the next morning, but it will also help you avoid bad decisions on every level, including food. In addition to impairing judgment, alcohol makes food smell better, leading to increased consumption, according to a recent study at Indiana University. The potential damage: 433 extra calories per meal, according to another study in the American Journal of Clinical Nutrition.

For more 31 Days of Fitness tips, check here for a new one every day in December.