7. YOGURT
Why: Low- or no-fat plain yogurt is a terrific source of B vitamins, protein, calcium and --if it has active cultures--the healthy bacteria known as probiotics, which crowd out disease-causing germs.

How Much: Four or more cups a week, if this is your main dairy source.

How: Cut back on sugar and calories by choosing plain yogurt and adding fruit, especially berries, and some granola. Or be more inventive:

Mix a dash of vanilla and chopped mint into yogurt and dollop on fruit
Use yogurt instead of sour cream for dips, sauces and salad dressings
Top baked potatoes with yogurt and chives
Thicken sauces and make soups "creamy" with yogurt
The payback part? As one of the Harvard researchers would likely tell you, eating a diverse diet that is low in calories and high in nutrients can make your RealAge as much as 4 years younger.

7.酸奶

原因：低或者是無脂肪的純酸奶是極好的維他命，蛋白質(zhì)，和鈣的來源并且如果有積極的文化——健康的細(xì)菌被認(rèn)為是益生菌，它能排擠致病菌的侵入。

分量：一星期至少4杯，如果它的你的主要的乳制品來源

如何食用：減少糖和卡路里用純酸奶和水果代替，特別是漿果類，和一些麥片。或者是更有創(chuàng)新的：

把香草和切碎的薄荷混合到酸奶和一塊水果上，用酸奶代替酸腐的奶油用來調(diào)味醬和沙拉醬，表面涂酸奶和韭菜去烤土豆，勾芡醬汁和用酸奶做湯

回報的部分呢？作為哈佛大學(xué)的一位研究人員很可能會告訴你，一份不同的飲食——卡路里很低而營養(yǎng)很高，可以讓你看上去比實際年齡年輕四歲。