10 Diet Mistakes That Slow Metabolism

Ignite your body's fat-burning furnace

10 eating habits that boost metabolism

You probably don't need scientists to tell you that your metabolism slows with age. But they're studying it anyway—and coming up with exciting new research to help rev it up again. The average woman gains 1 1/2 pounds a year during her adult life—enough to pack on 40-plus pounds by her 50s, if she doesn't combat the roller coaster of hormones, muscle loss, and stress that conspires to slow her fat-burning engine. But midlife weight gain isn't inevitable: We've found eating strategies that will tackle these changes.

But first, the basics: To boost over-40 weight loss, make sure your meals are around 400 calories, the amount needed to fuel your body while keeping you satisfied, translating into effortless weight loss. The following metabolism-boosting food rules were developed by Dan Benardot, PhD, RD, an associate professor of nutrition and kinesiology at Georgia State University, and Tammy Lakatos, RD. Here's how to adjust your eating plan to help your body burn fat. 

1. You don't eat enough

You need to cut calories to lose weight, but it's important not to overdo it. Going too low delivers a double whammy to your metabolism. When you eat less than you need for basic biological function (about 1,200 calories for most women), your body throws the brakes on your metabolism. It also begins to break down precious, calorie-burning muscle tissue for energy, says Benardot. "Eat just enough so you're not hungry—a healthy snack midmorning and midafternoon between three meals (about 430 calories each) will keep your metabolism humming." By eating a meal every 3 to 4 hours, you'll stay satisfied and keep from overeating later in the day.

2. You avoid caffeine

Caffeine is a central nervous system stimulant, so your daily java jolts can rev your metabolism 5 to 8%—about 98 to 174 calories a day. A cup of brewed tea can raise your metabolism by 12%, according to one Japanese study. Researchers believe the antioxidant catechins in tea provide the boost. 

3. Your carbs are white

Boost your fiber intake by switching to whole wheat bread, pasta, and eating more fruits and vegetables. Research shows that some fiber can rev your fat burn by as much as 30%. Studies find that women who eat the most fiber gain the least weight over time. Aim for about 25 g a day—the amount in about three servings each of fruits and vegetables.

4. Your water is room temperature

German researchers found that drinking 6 cups of cold water a day (that's 48 ounces) can raise resting metabolism by about 50 calories daily—enough to shed 5 pounds in a year. The increase may come from the work it takes to heat the water to body temperature. 

5. Your food is covered with pesticides

Canadian researchers report that dieters with the most organochlorines (pollutants from pesticides, which are stored in fat cells) experience a greater than normal dip in metabolism as they lose weight, perhaps because the toxins interfere with the energy-burning process. Other research hints that pesticides can trigger weight gain. Always choose organic when buying peaches, apples, bell peppers, celery, nectarines, strawberries, cherries, lettuce, imported grapes, and pears; non-organic versions tend to have the highest levels of pesticides.

6. Your meal lacks protein

Make sure protein is a component in every meal. Your body needs it to maintain lean muscle. Add a serving, like 3 ounces of lean meat, 2 tablespoons of nuts, or 8 ounces of low-fat yogurt, to every meal and snack. Research shows protein can up postmeal calorie burn by as much as 35%.

7. Your diet needs to pump iron

Iron-rich foods are essential for carrying the oxygen your muscles need to burn fat, says Lakatos. Until menopause, women lose iron each month through menstruation. Unless you restock your stores, you run the risk of low energy and a sagging metabolism. Shellfish, lean meats, beans, fortified cereals, and spinach are excellent sources or iron.

8. You're missing this crucial vitamin

Vitamin D is essential for preserving metabolism-revving muscle tissue. Unfortunately, researchers estimate that a measly 4% of Americans over age 50 take in enough through their diet. Get 90% of your recommended daily value (400 IU) in a 3.5-ounce serving of salmon. Other good sources: tuna, shrimp, tofu, fortified milk and cereal, and eggs.

9. You've had one drink too many

Skip the second cocktail. When you have an alcoholic drink, you burn less fat, and more slowly than usual, because the alcohol is used as fuel instead. Knocking back the equivalent of about two martinis can reduce your body's fat-burning ability by up to 73%.

10. You're not getting enough dairy

"There's some evidence that calcium deficiency, which is common in many women, may slow metabolism," says Lakatos. Research shows that consuming calcium through dairy foods such as fat-free milk and low-fat yogurt may also reduce fat absorption from other foods.