Limit consumption of energy-dense foods. That’s the advice from the latest international report on diet and cancer published by the American Institute for Cancer Research. The recommendation — aimed at promoting weight control — was included in the cancer-focused report because of the convincing link between overweight and several types of cancer.
The “energy-dense food” category referenced in the report includes foods that are concentrated in calories, usually because they are high in fat, processed carbohydrates and/or added sugar. Note, however, that some energy-dense foods — namely, nuts and seeds — are relatively unprocessed and supply many beneficial nutrients. These foods are not linked to weight gain when consumed moderately as part of a healthy diet.

Most Americans, however, are choosing the other kinds of energy-dense foods — those that the research links to an increased chance of weight gain, overweight and obesity. One popular consumer solution: Choosing reduced-fat or fat-free forms of the same foods. But these lower-fat options aren’t always lower in calories, particularly when they are consumed in jumbo portions.

A typical blueberry muffin purchased before the “super-sizing” of America’s food supply would have measured less than three inches in diameter and might have contained about 250 calories. Today, however, many bakeries and coffee shops serve muffins with twice the calories of the old-fashioned size. Even if a consumer chooses a low fat version (potentially dropping the fat content from 20 grams down to 2 grams), the muffin would still likely contain about 290 to 340 calories. In other words, the low fat, super-sized muffin is still higher in calories than the smaller, full-fat version. (Note that although low-fat muffins are no longer high-fat foods, their high-sugar content — up to eight teaspoons of sugar per muffin – keeps these foods in the energy-dense category.)

Reduced-fat versions of foods that start off as super-rich products can also be misleading. For example, a one-cup portion of conventional vanilla ice cream will cost you roughly 270 calories. Light versions, which trim the fat from 14 grams to 3 to 5 grams, can drop the calories to about 210 for the same portion size. However, decadent gourmet ice creams can contain from 480 to 580 calories per cup of vanilla ice cream. The light version of these products only reduces fat to the level of the conventional “full fat” ice cream. Because sugar content remains high, the 350 to 400 calories in gourmet light ice cream are often substantially higher than the regular version of conventional varieties.

Reduced-fat peanut butter is another example. Although lower in fat than regular peanut butter, with added sugar, starches and/or soy protein, the calories remain the same.

Not to discount all reduced-fat or low fat versions of foods — many do save calories. When purchasing cheese, milk and meat, for example, choosing the lower-fat products means less cholesterol-raising saturated fat and fewer calories. And if you just can’t live with fat-free cheese, even saving 20 calories per ounce with reduced-fat cheese can still be worthwhile.

The bottom line: By substituting a few lower-fat versions for the higher-fat foods you eat frequently, you can save calories, which can add up to make weight control easier. The key is to make those switches without simultaneously doubling your portion size or choosing the “light” version of a product richer than something you would normally choose.

最近一篇關于飲食和癌癥的報導建議控制消費高能量食物，這篇報道是由美國癌癥研究機構發(fā)布的。這個建議主要針對提高控制體重-曾經(jīng)也在一篇關于癌癥的報道里提到過，因為肥胖和癌癥之間有著令人信服的聯(lián)系。

報道中提及的高能量食物主要指卡路里含量高的食物，經(jīng)常是因為這些食物含高脂肪高碳水化合物和或含附加糖。然而，請注意，有些高能量食物，也就是那些相對未經(jīng)過加工有大量營養(yǎng)的堅果干果，當作為你健康飲食一部分合理食用時就不能把這些食物和長胖聯(lián)系起來。

然而，大部分美國人選擇其他種類的高能量食物，且研究表明這些食物增加增肥，超重和肥胖的幾率。一個很流行的消費者方案就是選擇同種食物的降脂或無脂產(chǎn)品。但是這些低脂肪食品并不總是意味低能量，尤其在你攝食比較多的情況下。

在美國食品供應處加大食品尺寸前，一個直徑小于三英寸的藍莓松餅可能含250卡路里能量。然而，今天許多面包店和咖啡店供應的松餅是原來老款式的兩倍大，即使消費者選擇低脂肪的松餅（脂肪已經(jīng)從20克降到2克），其能量也可能有290到340卡路里。換句話說，低脂肪超大個的松餅所含的能量要比全脂個小的高。（注：盡管低脂松餅不再屬于高脂食物，但是高含糖量使這些食物依舊屬于高能量類。

起初作為超級有錢人的降脂版的食物也是一個誤導。例如，一杯傳統(tǒng)的香草冰激凌含270卡路里，輕脂版從原來14克改為現(xiàn)在的3到5克，同等大小的熱量降到了21o卡路里。然而，精致冰激凌每杯含480到580卡路里能量。輕版產(chǎn)品只是將脂肪降到了傳統(tǒng)全脂冰激凌的水平。因為糖分含量依然很高，350到400卡路里的精致輕版冰激凌往往比普通傳統(tǒng)版的含糖量要高。

降脂花生醬也是一個很好的例子。盡管脂肪比普通的要低，但是附加糖，淀粉，大豆蛋白使能量和原來一樣。

不要考慮所有的降脂或低脂食物，許多也能減少能量。例如，當你購買奶酪，牛奶，肉類時，選購低脂產(chǎn)品意味更少膽固醇飽和脂肪和更少的能量。如果你的生活不能缺少無脂奶酪，即使每盎司減少20卡路里，選擇那些降脂奶酪，也是值得的。

底線：通過食用低脂版取代你經(jīng)常食用的高脂食物，你不僅可以減少能量的攝入，也可幫助你更好的控制體重。關鍵是做好轉(zhuǎn)換，既不會同時增大你選擇的量，也不會選擇比你平常選擇的糖分還要多的輕版產(chǎn)品。