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

无需科学家告诉你，你就该知道新陈代谢会随着年龄的增长而减缓。科学家正在研究，得出了促进代谢的新研究成果。一般成年妇女每年会增重1.5磅，如果不锻炼，任由发展的话，到了50岁的时候，估计得重个40几磅。不过因为人上中年而增加的重量并不是不可避免的: 我们已经发现通过锻炼和控制饮食来解决这个困扰的方法。

通过锻炼来预防代谢减缓可以使得你在四周内减去8磅的重量。更重要的是你可以塑造处结实的肌肉-这对旺盛的代谢是很重要的。不过这还是开始。为了使你的代谢真正得到增强，你还得同时用可促进代谢的饮食来搭配，这份饮食是Dan研究出来的，dan是乔治亚州立大学营养和运动学专业的副副教授。从今天起就按照Dan的想法做，你能岁的更好，更有精力，更结实，在两周内你就能发现自己瘦了。现在就让我们来看看：

要吃的足够多

要减少体重就要切断卡路里的来源，但是卡路里不够，新陈代谢反而被减缓。如果你吃的太少，都满足基本生物功能运作，你的身体就会停止代谢。同时肌肉组织将被分解作为能量的来源。研究人员Dan说：“要吃的足够多，保证自己不饿，三餐之外（每餐保证430卡）还要在上午十点和下午三点的时候吃份大约150卡的零食，这样能促进代谢。”

早饭很重要

吃早饭能给一天的新陈代谢开个好头并让人一天都精神慢慢。不吃早饭的女人变胖的可能性是吃早饭女人的4.5倍。早饭时候吃燕麦泡脱脂奶，再撒点坚果--用高蛋白开始你的一天！

喝咖啡或茶

咖啡因能刺激中央神经系统，每天喝点含咖啡因的饮料可以使新陈代谢增加5%至8%，即98-174卡。据日本研究一杯好茶可使代谢增加12%，研究人员相信这是茶叶中的儿茶酚抗氧化剂的功劳。

纤维减肥

研究人员调查显示有些纤维能加速30%的脂肪燃烧量。研究还显示女士吃纤维吃的越多，变胖的可能性就相对小。每天争取摄入25克纤维-相当于每日吃三分水果蔬菜。

买个大瓶子

德国研究人员调查现实每天喝6大杯约48盎司凉水能够使每日休息代谢提高50%，如此下来一年可减重5盎司。喝冷水之所以有这个功效也学是因为身体要把水加热到体温要消耗能量。

食用有机食品

加拿大研究人员报告：受农药污染的食品含有氯，贮存在脂肪细胞里，有毒物质会干扰能量燃烧过程，将导致食用者新陈代谢下降。其他调查显示农药导致体重上升。购买时要选择有机桃子，苹果，甜椒，芹菜，油桃，草莓，樱桃，生菜，进口葡萄，梨，非有机产品往往有高含量农药。

不要忘记蛋白质

人体需要蛋白质来塑造肌肉。吃饭的时候多吃3盎司瘦肉，吃零食的时候多吃两汤匙坚果或是8盎司的低脂酸奶，都可以补充蛋白质。研究表示蛋白质可使餐后卡路里燃烧值提高35%

吃富含铁的食物

Lakatos说保持肌肉含氧量对燃烧脂肪十分重要。妇女在绝经前每月都会因为月经而流失铁。如果不及时补充，就会体能不支，代谢下降。贝类，瘦肉，豆类，精谷，菠菜都是铁的最佳来源。

摄取更多维生素D

维生素对人新陈代谢中肌肉的产生至关重要。据研究人员估计50岁以上的美国人大约只有4%能在日常饮食中摄入足够的维生素。3.5盎司的鲑鱼肉能满足每日400UI单位维生素的推荐需求量。金枪鱼，虾，豆腐，强化奶，麦片，鸡蛋，都富含维生素。

不要喝第二杯鸡尾酒

喝酒的时候酒精作为能量燃烧，于是人体内脂肪燃烧量就变少变慢。相当于两杯马丁尼酒分量的酒精饮料可以使你身体燃脂能力下降73%

喝牛奶

Lakatos说：“有证据显示缺钙会减缓新陈代谢速度，而缺钙在女人中是很常见的。”研究显示通过食用脱脂牛奶或低脂酸奶的奶制品来补钙能减少从其他食物里吸收脂肪