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 a diet plan that will tackle these changes.  Here's what you need to do:

Eat Enough

You need to cut calories to lose weight, but 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.  Eat just enough so you're not hungry—a 150-calorie snack midmorning and mid-afternoon between three meals (about 430 calories each) will keep your metabolism humming.

Rev Up in the Morning

Eating breakfast jump-starts metabolism and keeps energy high all day. It's no accident that women who skip this meal are 4 1/2 times as likely to be obese. If nothing else, grab a yogurt. Or try oatmeal made with fat-free milk and topped with nuts for an essential protein boost.

Drink Coffee or Tea

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 in tea provide the boost.

Fight Fat with Fiber

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.

Buy the Big Bottle

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.

Go Organic

Canadian researchers report that dieters with the most “organo-chlorines” (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, cherries, lettuce, imported grapes, and pears; they tend to have the highest levels of pesticides.

Always Include Protein

Your body needs protein 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 increase post-meal calorie burn by as much as 35%.

Eat Iron-Rich Foods

It's essential for carrying the oxygen your muscles need to burn fat.  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.

Get More D

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

Skip the Second Cocktail

When you have a 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%.

Drink Milk

There's some evidence that calcium deficiency, which is common in many women, may slow metabolism. 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.

Start these strategies today and you'll sleep better, have more energy, feel firmer, and notice your clothes are looser in as little as 2 weeks. 

Source:prevention.com