How Fats Work

The most common fatty acids are found in animal fats and include:

Your body is able to create these fats whenever it has acaloric surplus。它可以创建直接年代ugar if there are enough sugar calories coming in (seeHow Food Worksfor a discussion of carbohydrates and sugar).

It turns out that there is another class of fatty acids calledessential fatty acidsthat your body cannot manufacture. These fatty acids include:

Because your body cannot manufacture them, they must come in from the food you eat.

Essential fatty acids fall into two groups: omega-3 and omega-6. The 3 and 6 refer to the first carbon double bond position on the fatty acid chain. All essential fatty acids are polyunsaturated, so the 3 and the 6 mean that the first double bond is either 3 or 6 carbons in from the end.

Omega-6 fatty acids are everywhere: corn oil, sunflower oil and soybean oil all contain them. Omega-3 fatty acids are harder to find. Things like flax seeds, pumpkin seeds and walnuts are high in omega-3 fatty acids, as are salmon, trout and tuna. Current thinking is that these two fats need to be balanced in the diet at a ratio like 1-to-1 or 2-to-1, rather than the normal 20-to-1 ratio seen in most Western diets. About the only way to do that is to supplement your diet with omega-3 vegetable oils or to start eating fish in a big way (meaning two or three times a week).

Summarizing all of this information, the current scientific thinking on fat consumption goes something like this:

For more information on fats, nutrition and related topics, check out the links below.

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