Introduction

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 an exercise and diet plan that will tackle these changes.

Prevention's customizable metabolism-boosting workout will help you shed up to 8 pounds in just 4 weeks. Most important, you'll build firm, lean muscle tissue — the key to a robust metabolism. But that's just the beginning. To really make your metabolism soar, couple the workout with our High-Metabolism Diet, developed by Dan Benardot, PhD, RD, an associate professor of nutrition and kinesiology at Georgia State University, and Tammy Lakatos, RD, co-author of "Fire Up Your Metabolism." Start today and you'll sleep better, have more energy, feel firmer, and notice your clothes are looser in as little as two weeks. Click on the arrows above to learn how.

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, says Dan Benardot. "Eat just enough so you're not hungry — a 150-calorie snack midmorning and midafternoon 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 percent 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 fiber

Research shows that some fiber can rev your fat burn by as much as 30 percent. 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 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.

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 up postmeal calorie burn by as much as 35 percent.

Eat iron-rich foods

It's essential for carrying the oxygen your muscles need to burn fat, says Tammy Lakatos, RD, co-creator of the diet. 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.

Get more D

This vitamin is essential for preserving metabolism-revving muscle tissue. Unfortunately, researchers estimate that a measly 4 percent of Americans over age 50 take in enough through their diet. Get 90 percent 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.

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 percent.

Drink milk

"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.

序

無需科學(xué)家告訴你，你就該知道新陳代謝會隨著年齡的增長而減緩�？茖W(xué)家正在研究，得出了促進代謝的新研究成果。一般成年婦女每年會增重1.5磅，如果不鍛煉，任由發(fā)展的話，到了50歲的時候，估計得重個40幾磅。不過因為人上中年而增加的重量并不是不可避免的: 我們已經(jīng)發(fā)現(xiàn)通過鍛煉和控制飲食來解決這個困擾的方法。

通過鍛煉來預(yù)防代謝減緩可以使得你在四周內(nèi)減去8磅的重量。更重要的是你可以塑造處結(jié)實的肌肉-這對旺盛的代謝是很重要的。不過這還是開始。為了使你的代謝真正得到增強，你還得同時用可促進代謝的飲食來搭配，這份飲食是Dan研究出來的，dan是喬治亞州立大學(xué)營養(yǎng)和運動學(xué)專業(yè)的副副教授。從今天起就按照Dan的想法做，你能歲的更好，更有精力，更結(jié)實，在兩周內(nèi)你就能發(fā)現(xiàn)自己瘦了�，F(xiàn)在就讓我們來看看：

要吃的足夠多

要減少體重就要切斷卡路里的來源，但是卡路里不夠，新陳代謝反而被減緩。如果你吃的太少，都滿足基本生物功能運作，你的身體就會停止代謝。同時肌肉組織將被分解作為能量的來源。研究人員Dan說：“要吃的足夠多，保證自己不餓，三餐之外（每餐保證430卡）還要在上午十點和下午三點的時候吃份大約150卡的零食，這樣能促進代謝。”

早飯很重要

吃早飯能給一天的新陳代謝開個好頭并讓人一天都精神慢慢。不吃早飯的女人變胖的可能性是吃早飯女人的4.5倍。早飯時候吃燕麥泡脫脂奶，再撒點堅果--用高蛋白開始你的一天！

喝咖啡或茶

咖啡因能刺激中央神經(jīng)系統(tǒng)，每天喝點含咖啡因的飲料可以使新陳代謝增加5%至8%，即98-174卡。據(jù)日本研究一杯好茶可使代謝增加12%，研究人員相信這是茶葉中的兒茶酚抗氧化劑的功勞。

纖維減肥

研究人員調(diào)查顯示有些纖維能加速30%的脂肪燃燒量。研究還顯示女士吃纖維吃的越多，變胖的可能性就相對小。每天爭取攝入25克纖維-相當(dāng)于每日吃三分水果蔬菜。

買個大瓶子

德國研究人員調(diào)查現(xiàn)實每天喝6大杯約48盎司涼水能夠使每日休息代謝提高50%，如此下來一年可減重5盎司。喝冷水之所以有這個功效也學(xué)是因為身體要把水加熱到體溫要消耗能量。

食用有機食品

加拿大研究人員報告：受農(nóng)藥污染的食品含有氯，貯存在脂肪細胞里，有毒物質(zhì)會干擾能量燃燒過程，將導(dǎo)致食用者新陳代謝下降。其他調(diào)查顯示農(nóng)藥導(dǎo)致體重上升。購買時要選擇有機桃子，蘋果，甜椒，芹菜，油桃，草莓，櫻桃，生菜，進口葡萄，梨，非有機產(chǎn)品往往有高含量農(nóng)藥。

不要忘記蛋白質(zhì)

人體需要蛋白質(zhì)來塑造肌肉。吃飯的時候多吃3盎司瘦肉，吃零食的時候多吃兩湯匙堅果或是8盎司的低脂酸奶，都可以補充蛋白質(zhì)。研究表示蛋白質(zhì)可使餐后卡路里燃燒值提高35%

吃富含鐵的食物

Lakatos說保持肌肉含氧量對燃燒脂肪十分重要。婦女在絕經(jīng)前每月都會因為月經(jīng)而流失鐵。如果不及時補充，就會體能不支，代謝下降。貝類，瘦肉，豆類，精谷，菠菜都是鐵的最佳來源。

攝取更多維生素D

維生素對人新陳代謝中肌肉的產(chǎn)生至關(guān)重要。據(jù)研究人員估計50歲以上的美國人大約只有4%能在日常飲食中攝入足夠的維生素。3.5盎司的鮭魚肉能滿足每日400UI單位維生素的推薦需求量。金槍魚，蝦，豆腐，強化奶，麥片，雞蛋，都富含維生素。

不要喝第二杯雞尾酒

喝酒的時候酒精作為能量燃燒，于是人體內(nèi)脂肪燃燒量就變少變慢。相當(dāng)于兩杯馬丁尼酒分量的酒精飲料可以使你身體燃脂能力下降73%

喝牛奶

Lakatos說：“有證據(jù)顯示缺鈣會減緩新陳代謝速度，而缺鈣在女人中是很常見的。”研究顯示通過食用脫脂牛奶或低脂酸奶的奶制品來補鈣能減少從其他食物里吸收脂肪