Perspectives on protein and nutrition

When it comes to nutrition, probably everyone knows that our bodies need protein to build muscle. Probably everyone knows that meat, poultry, fish, eggs, and dairy products are good sources of protein.

Unfortunately, it appears that most Americans think those are the only protein sources. They do not consider plant-based sources of protein. Also, most Americans eat too much meat. Eating too much meat means that they actually eat too much protein for good nutrition.

With the possible exception of some fish, no food consists mostly of protein. Most of the calories from meat, poultry, or dairy products come from fat (9 calories per gram). Most of the calories from various plants come from carbohydrates (4 calories per gram).

The best nutritional balance comes from eating mostly plant foods (including whole grains) and using meat more for flavor than as the centerpiece of a meal. An adequate serving of meat is about the size of a deck of cards. Our bodies don't even need meat or poultry every day.

Eggs provide the most nearly perfect protein, that is, the correct balance of amino acids our bodies need to obtain from food. Most plant-based proteins fall far short of that balance, usually including more of some amino acids and less of others.

As it turns out, however, we can obtain protein as  nearly perfect as that in eggs by combining different plant foods with offsetting strengths and weaknesses. For convenience, I am dividing plant-based protein sources into three groups: whole grains, legumes (beans, peas, lentils, and peanuts), and nuts and seeds (sesame and sunflower, for example).

Grains and legumes make one complementary combination. Many dishes combine rice and beans or corn and beans. Different varieties of Mexican food alone demonstrate the possibilities. Even  a peanut butter sandwich on some kind of whole grain bread offers more nearly perfect protein than either ingredient has separately.

Legumes and nuts or seeds likewise complement each other. That is, each makes up what the other lacks to make perfect protein. Hummus, for example, combines garbanzo beans (also called chick peas) and sesame seeds. Sunflower seeds and peanuts make another combination. (Nuts in general provide many nutritional benefits, but they are also higher in fat than most plant foods. Use them carefully.)

Combining grains with dairy products likewise creates a more nearly perfect protein (although dairy by itself is a closer approximation than any plant source). Use non-fat milk or yogurt to avoid adding too much fat.

And don't forget: other vegetables not  part of one of my groups also contain significant protein, including potatoes and mushrooms.

The best part of getting nutrition mostly from plants is that we don't even have to eat two complementary foods in the same meal to get nearly perfect protein. Our body can get a protein boost from them if we eat them the same day. It is probably impossible to eat enough calories to get us through a day not get enough protein, whether we eat any animal products or not.