COMPLETE AND INCOMPLETE PROTEINS
Getting the right kinds of protein is similar to shopping for clothes. Some clothing comes in complete sets. The jacket is sold with the skirt or pants and together they make a complete outfit. With other clothing you mix and match: jeans from one rack, a shirt from another, maybe a sweater from a different store across town. Proteins, too, come in complete sets or as incomplete parts that work together. A complete protein contains all nine of the essential amino acids; a protein missing one or more of these is an incomplete protein. Naturally, foods that come from species closest to humans (i.e., animal foods) contain complete proteins, since animal tissues have an amino acid composition similar to our own. Both grains and legumes contain significant amounts of protein, but these proteins do not contain all of the essential amino acids. Except for soybeans, plant proteins do not contain all the essential amino acids, so they are called incomplete proteins.

Another way to evaluate proteins is to consider the biological value (BV) of a protein, meaning not only how rich it is in essential amino acids, but also how well it can be digested by the intestines. Animal proteins are around 95 percent digestible and plant proteins range between 80 and 90 percent digestible.

Complimenting and combining proteins. While it may seem that animal proteins are better nutritionally, the differences in quality between animal and plant proteins are more theoretical interest than practical significance. People can grow just as well on plant proteins. (Plant-protein eaters may even be healthier, since they avoid the fat that comes with animal protein.) One plant food can supply the amino acids missing in another. Proteins from different kinds of plants complement each other and, in fact, many common and traditional foods are based on complementary proteins.

Don't be misled into thinking that you must eat meat twice a day or even once a day to get the protein you need. Even though plant proteins are not complete proteins, you can make up for what any one food lacks by eating a wide variety of plant and dairy foods. A hefty salad with a sprinkling of parmesan cheese and a topping of sunflower seeds is a healthy protein lunch.

The amount of protein you need depends primarily on the size of your body and how fast it is growing, and to a lesser extent on your gender and how much you exercise. Babies need more protein per pound than moms, moms more than grandmothers, and dads more than moms. As a general guide, this is the amount of protein that the average person needs at various ages:

AGE PROTEIN PER POUND DAILY PROTEIN NEEDS Birth - 6 months 1 gm. 13 gms. 6 months - 1 year .75 gm. 14 gms. 1 - 6 years .6 gms. 16-24 gms. 7 - 15 years .5 gms. 28-50 gms. Adults .36 gms. 50-60 gms.

GROWTH SPURTS
Growing children need more "grow" foods (i.e., proteins). During the first two months of life, fifty percent of the protein in a baby's diet is used for growth and the other fifty percent is used for continued maintenance of the tissues. By three years of age, only eleven percent of dietary protein is used for growth. During the periodic growth spurts of infancy, childhood, and adolescence, you may need to perk up the proteins in your child's diet anywhere from five to fifteen grams more a day.

Animal proteins are better tailored to meet the needs of infants and growing children than are plant proteins, which is why nature provides human milk for babies. The complete proteins in breastmilk are more suited to a growing infant's needs than plant protein, which is found in some formulas. Even babies in vegan families get an animal-based food if they are breastfed.

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JUST HOW MUCH PROTEIN DO YOU REALLY NEED?
The usual figures that are thrown around concerning protein needs are "15 to 20 percent of total daily calories." For most individuals this is much too high. The average infant, child, and adult can get all the protein they need without having daily calories from protein exceed 10 percent of their total calories. For example, if you eat an average of 2,000 calories a day, about 200 calories of this should be protein. Protein contains four calories per gram, so this would be about 50 grams of protein (200 divided by four calories/gram equals 50 grams). Most children and adults get at least ten percent of their total daily calories as protein without even trying. In times of increased protein needs (such as pregnancy, lactation, adolescent growth spurts, or high endurance exercise), this figure may increase to 15 percent.

You'll be surprised how easy it is for your child to get enough protein. If she is at an average weight for 3-year-olds, around 30 pounds, she needs an average of sixteen grams of protein. She can get this amount from any one of the following:

Perhaps the fairest and most practical way of rating protein foods is to look at the amount of protein in relation to the total calories in a food. The following chart will show you how to get enough protein without overdosing on fat.

Protein Food Grams of Protein per serving Percentage of calories as protein Fish, tuna (4 oz) 25-30 83% Egg white (1) 3.5 82% Cottage cheese, nonfat (1/2 c.) 15 75% Poultry, breast, no skin (4 oz) 25 75% Kidney beans (1/2 cup) 7 60% Tofu, firm (3 oz) 13 45% Yogurt, plain nonfat (1 cup) 12 40% Beef, lean (4 oz) 30 40% Egg, whole (1) 6 33% Milk, 1% (8 ounces) 8 32% Peanut butter (2 tbsp.) 8 17% Cereal (1 cup) with 1/2 c. milk 6-8 17% Nuts or sunflower seeds (oz.) 7 16% Pasta (1 cup) 7 15% Whole wheat bread (1 slice) 3 15%

THE MOST POWERFUL PROTEINS
Some proteins are more powerful than others. What makes one protein more powerful than another is not only whether it contains all the essential amino acids, but how many different amino acids it contains. That's why nutritional scientists use the Protein-Energy Ratio (PER) and Biological Value (BV) ratings of proteins, which measure how well the body utilizes amino acids in a protein. Here's how the main proteins rate (from highest to lowest) by how well they are utilized in the body.

Too much protein is not a problem, unless you really overdose, which would mean eating twice the amount your body needs for a long time. When your body has more protein than necessary, it simply disassembles the excess protein, uses the amino acids it needs, and discards the leftover nitrogen through the kidneys. The body can't store protein the way it stores energy in fat tissues. Sometimes when someone eats too much protein over a long time, the body will either break down the protein and use it as an energy source or deposit it as fat. You virtually never have to worry about children getting too much protein; in fact, parents usually worry about picky eaters not getting enough protein. Excess protein is not usually a worry for adults either, unless they are suffering from kidney disease.

Be careful with these. It is generally unwise to use a high protein diet to lose weight. The protein overdose sends the kidneys into overtime. As the kidneys work to eliminate the excess protein, they also dump a lot of water out of your system. On the bathroom scale, this looks like a dramatic weight loss, but it is not a real weight loss. (What you really want to lose is fat.) If you lose too much water weight too fast you could harm your health. It is generally wise to consume extra amounts of water if eating extra protein. High protein diets are potentially harmful for people with kidney or liver insufficiency. Before trying this type of diet, be sure to consult your doctor and a registered dietitian.

The reason that high protein diets "work" is the same reason that other weight loss diets work: they are lower in calories. High protein diets substitute fish and vegetable protein for meat and dairy protein, and this reduces the amount of fat in the diet. Basically, high protein diets are weight loss gimmicks. Promoting proteins and bad-mouthing carbs are just ways to get attention. There is little research to show that this approach works or, more importantly, is safe. Use common sense. Any diet in which you eat fewer calories than you burn will result in loss of body fat, regardless of whether the diet contains primarily fat, carbohydrates, or proteins. Your grandmother could have told you this without even writing a bestseller. Eat a balanced diet and don't eat more calories than you burn. That's the secret of weight control.

Just eating more muscle will not make you gain muscle. But, if you're trying to build your muscles through exercise, you may need more protein. How much depends upon how hard you're working out. An average person working out to stay healthy, but not on a vigorous exercise and weight-training program, will need around 1/2 gram of protein per pound per day. Studies have shown that athletes undergoing vigorous exercise for two hours per day need double that amount of protein, around a gram of protein per pound per day. Serious weight-lifters may need to even go up to a gram and a half of protein per pound per day. For most teens and adults on vigorous exercise programs, increasing their daily protein by one-third (roughly 16 to 20 grams of meat or fish) is sufficient.

No, it used to be believed that for two incomplete plant proteins to complement each other and give the body all the essential amino acids, they had to be eaten at the same meal. Being a vegetarian seemed complicated, even risky. Now we know that this is not only nutritionally incorrect, it is an insult to the wisdom of the body. When you eat a protein, your body disassembles it into amino acids and then reassembles these amino acids into the types of proteins needed by different cells. New studies show that incomplete proteins (plant proteins) eaten as much as 24 hours apart, combine in the body to provide all the essential amino acids. So, you could eat grains at breakfast and legumes at dinner, and the body will still be able to mix them all together and make what it needs. As long as you eat a variety of protein foods from a variety of sources, you don't have to constantly worry whether they are "complete" or "incomplete" proteins. Your body will do the thinking for you.