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  3. Calories are among the most often counted things in the universe.【F1】Estimates of the number of calories in different kinds of f

Calories are among the most often counted things in the universe.【F1】Estimates of the number of calories in different kinds of f

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问题     Calories are among the most often counted things in the universe.【F1】Estimates of the number of calories in different kinds of foods measure the average number of calories we could get from those foods based only on the proportions of fat, carbohydrates, protein and sometimes fiber they contain. A variety of standard systems exist, all of which derive from the original developed by Wilbur Atwater more than a hundred years ago. They are all systems of averages. No food is average.
    Differences exist even within a given kind of food. Take, for example, cooked vegetables. Cell walls in some plants are tougher to break down than those in others; nature, of course, varies in everything. If the plant material we eat has more of its cell walls broken down we get more of the calories from the goodies inside.【F2】In some plants, cooking breaks down most cell walls; in others, such as cassava(木薯), cell walls hold strong and hoard their precious calories in such a way that many of them pass through our bodies intact. Why are foods yielding fewer calories than they "should"? Tough cell walls? Maybe. But there are other options too.
    For one, our bodies seem to expend different quantities of energy to deal with different kinds of food; some foods require us to do more work than others. Proteins can require ten to twenty times as much heat-energy to digest as fats, but the loss of calories as heat energy is not accounted for at all on packaging.
    For another, foods differ in how and where they are digested in our guts. Some foods such as honey are so readily used that our digestive system is really not even put to good use. They are absorbed in our small intestines; game mostly over.【F3】More complex foods, on the other hand, such as cassava or almonds(杏仁), have to travel to the colon(结肠)where they meet up with the largest concentrations of our little friends, the microbes(微生物). Digestion continues with the help of our trillions of microbes but nutrients are shared between us and them.【F4】The microbes help to break down many compounds our own bodies cannot and in doing so go on to produce a mix of more microbes, gases(such as methane)and then fatty acids.
    The accounting associated with this process of sharing with the microbes is not considered in calorie counting. Finally, some foods require our immune system to get involved during digestion in order to deal with potential pathogens. No one has evaluated very seriously just how many calories this might involve, but it might be quite a few. A somewhat raw piece of meat can have lots of interesting species for our immune systems to deal with.【F5】Even if our immune system does not attack any of the species in our food it uses energy to take the first step of distinguishing good from bad.
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答案对于某些植物而言，烹饪能够破坏绝大部分的细胞壁；而对于其他一些植物，例如木薯，细胞壁坚实地保护着它们宝贵的卡路里以至于很多细胞都是原封未动地在人体内旅行了一遭。
解析 该句是个并列句。主体结构是并列转折句。In some plants和in others分别表述烹饪对不同植物细胞壁的影响。因为两个并列句是转折关系，因此翻译时可采用增词法，增加“然而”一词说明两者之间的关系；另外，第二个并列句中包括一个such…that…引导的结果状语从句，根据其语法意义，在翻译时译为“以至于”，强调这些植物细胞壁的坚实程度。
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