Here are a few rules to get you started, recommended by study author Judith S. Stern, ScD, RD:  Eat a cookie Participants stayed satisfied by enjoying a daily 100-calorie “bonus” serving such as salad dressing, butter, or even an occasional sweet. Downsize your kitchenware To keep portion sizes under control, grab a juice glass instead of a tall one, a salad plate instead of the oversized kind, and teaspoons instead of serving spoons for condiments and sauces. (Check out these kitchen tools that can help you lose weight.) Plan for the future Create a 7-day menu, and shop now, when you can make a week’s worth of smart choices at once. Have an orange a day Since no one seems to get enough, participants added an extra fruit, vegetable, or low-fat dairy product to each of their meals. This is as simple as an orange at breakfast, yogurt at lunch, and a salad with dinner. More from Prevention: 100 Simple Ways To Lose Weight