Eat the HeatIt turns out that capsaicin, the compound that gives chili peppers their mouth-searing quality, can also fire up your metabolism. Eating about 1 tablespoon of chopped red or green chilies boosts your body's production of heat and the activity of your sympathetic nervous system (responsible for our fight-or-flight response), according to a study published in the Journal of Nutritional Science and Vitaminology. The result: a temporary metabolism spike of about 23 percent. Stock up on chilies to add to meals, and keep a jar of red pepper flakes on hand for topping pizzas, pastas, and stir-fries.
Rev Up in the MorningEating breakfast jump-starts metabolism and keeps energy high all day. It's no accident that those who skip this meal are four and a half times as likely to be obese. And the heartier your first meal is, the better. In one study published by the American Journal of Epidemiology, volunteers who got 22 to 55 percent of their total calories at breakfast gained only 1.7 pounds on average over four years. Those who ate zero to 11 percent of their calories in the morning gained nearly 3 pounds.
Drink Coffee or TeaCaffeine is a central nervous system stimulant, so your daily java jolt can rev your metabolism 5 to 8 percent—about 98 to 174 calories a day. A cup of brewed tea can raise your metabolism by 12 percent, according to one Japanese study. Researchers believe the antioxidant catechins in tea provide the boost.
Fight Fat With FiberFiber can rev your fat burn by as much as 30 percent. Studies find that those who eat the most fiber gain the least weight over time. Aim for about 25 grams a day—the amount in about three servings each of fruits and vegetables.
Eat Iron-Rich FoodsIron is essential for carrying the oxygen your muscles need to burn fat. Unless you restock your store, you run the risk of low energy and a sagging metabolism. Shellfish, lean meats, beans, fortified cereals, and spinach are excellent sources. (But it's not always a good idea to take a supplement. Too much iron has been linked to a greater risk of heart disease in men. Get this essential mineral in natural doses from real foods.)
Get More DVitamin D is essential for preserving metabolism-revving muscle tissue. Unfortunately, researchers estimate that a measly 20 percent of Americans take in enough through their diet. Get 90 percent of your recommended daily value (400 IU) in a 3.5-oz. serving of salmon. Other good sources: tuna, fortified milk and cereals, and eggs.
Drink MilkThere's some evidence that calcium deficiency may slow metabolism. Research shows that consuming calcium in dairy foods such as fat-free milk and low-fat yogurt may also reduce fat absorption from other foods.
Eat WatermelonThe amino acid arginine, abundant in watermelon, might promote weight loss, according to a new study in the Journal of Nutrition. Researchers supplemented the diets of obese mice with arginine over 3 months and found that it decreased body-fat gains by a whopping 64 percent. Adding this amino acid to the diet enhanced the oxidation of fat and glucose and increased lean muscle, which burns more calories than fat does. Snack on watermelon and other arginine sources, such as seafood, nuts, and seeds, year-round.
Stay HydratedAll of your body's chemical reactions, including your metabolism, depend on water. If you are dehydrated, you may be burning up to 2 percent fewer calories, according to researchers at the University of Utah who monitored the metabolic rates of 10 adults as they drank varying amounts of water per day. In the study, those who drank either eight or twelve 8-ounce glasses of water a day had higher metabolic rates than those who had four.