Have a PB & J
Think peanut butter is only for pint-sized palates? Think again. PB is rich in magnesium, a mineral that motors up your metabolism by giving your cells energy. Aim for 320 mg a day of magnesium: Good food sources include a peanut butter sandwich made with whole-wheat bread (100 mg) or spinach (1/2 cup has 80 mg).
Exercise off that PMS
You could lose more weight exercising during the later phase of your menstrual cycle than at any other time in your cycle, according to a recent study from the University of Adelaide in Australia. Hormones estrogen and progesterone fire up your fat-burning furnace: They promote your body's use of fat as an energy supply, so more is burned off when you exercise. "Women burned about 30 percent more fat for the two weeks following ovulation to about two days before menstruation," explains study author Leanne Redman.
Don't blow off breakfast
Studies show that eating breakfast plays a part in successful weight loss -- almost 80 percent of people who successfully keep weight off chow down on this meal, according to a study published in Obesity Research. "Your metabolism slows as you sleep, and the process of digesting food revs it up again," explains Heller. Aim for a 300- to 400-calorie breakfast, such as a high-fiber cereal (another metabolism booster) with skim milk and fruit.
Pump up protein
Not in an extreme, Atkins sort of way, but having a little protein at every meal fires up your metabolism. "Your digestive system uses more energy to break it down, so you burn more calories," explains Lisa Dorfman, R.D. However, keep protein levels to between 20 and 35 percent of your diet; eating too much of it can cause kidney strain and may cause your body to store too much fat.
Read more: 21 Ways to Burn Fat Faster - Redbook