Because the oil is used as a reserve nutrient—like fat—diatoms have evolved no mechanism to secrete it.

由于油的作用是营养储备——就象脂肪似的——所以硅藻没有进化出分泌油份的机制。

youdao

Foods that are high in salt, sugar, fat or calories and low nutrient content. are junk foods.

食物是在高盐、糖、脂肪和卡路里和低营养content .是垃圾食物。

youdao

Commercial pizza is now a high-calorie, high-fat, high-sodium, low-nutrient food.

比萨商品是一个高卡路里、高脂肪、高钠和低营养的食物。

youdao

They're the magic nutrient books: carbohydrates, fat, whatever it happens to be, that's one theme you could follow.

它们是些神奇的营养学书籍,碳水化合物,脂肪,或者其它东西,都可以成为著书的主题

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Make sure that you eat lots of nutrient-dense foods such as whole grains, low-fat dairy and brightly colored fruits and vegetables, both for your health and your baby's.

CNN: How can I safely control my pregnancy weight gain?

Fat-free foods don't fit into a nutrient-dense diet unless they're naturally free of fats, like vegetables and fruit.

CNN: Get the biggest bang for your calorie with nutrient-dense food

Researchers don't know why a plant-based diet seems to have a protective effect, but one likely reason is the nutrient profile of vegetarian diets, which tend to be higher in fiber and lower in saturated fat.

WSJ: Vegetarians Live Longer Than Meat-Eaters, Study Finds