100A - Fit and Well Column for December 5th, 2004

TITLE: "Protein Power!"

Dear David and Trish,

In my reading about fitness, writers often speak about protein, and how important it is. Can you give me some basic information on why it is so important, and just how much protein is necessary in a balanced diet?

Sincerely,

Brad in Bowie

Dear Brad,

The first question is relatively easy to answer, the second one is more complicated. But we'll give you some guidelines to work with.

Protein is one of three basic classes of foods often called macronutrients. The other two are fats and carbohydrates. We get our protein primarily from animal products like poultry, beef, pork and anything that swims and doesn't use scuba gear. It is also present in animal by-products, such as eggs, milk and cheese. And there’s vegetable protein, such as that found in soybeans.

Proteins are essential nutritionally because of their constituent amino acids, which the body demands to synthesize other proteins required for life.

Amino acids are made-up of different atoms, which form different molecules. The common thread is that every amino acid has a nitrogen atom in it. Nitrogen is very important to overall homeostasis or the smooth running and balance of the body.

Protein is essential because it is made of amino acids, the building blocks of our muscles, organs, hair, toenails, neurotransmitters, enzymes and just about anything else you need to keep going.

The importance of protein in nutrition and health cannot be overemphasized. It seems appropriate that the Greeks chose the word "proteous" meaning "primary" or "taking first," for this nutrient. The main storehouse of proteins is muscle tissue.

The protein we eat is broken-down into the amino acids. The amino acids from our diet are used in different ways. They are used in the synthesis of new proteins, like building up internal and skeletal muscle tissue. When present in excess, they are used as fuel for the body, or can even be stored as fat. PLEASE remember this! Protein CAN be stored as fat, so how much you consume is critical. More on that later.

When you enter a "starvation mode" (no available protein available for your body's needs) the body goes into a defense posture and will look for its only storehouse of protein…THE MUSCLE TISSUE. This is what is called "catabolism", or more simply the breakdown of muscle tissue. That's right! The very tissue you are trying to build-up and keep by your visits to the gym is actually used for fuel! Too much exercise, and not enough protein, means less muscle, not more! Yipes!

Your body has exact protein requirements based on your level of activity, weight training goals and health maintenance.

How much do YOU need?

That depends on whom you ask. The currently advocated number--which many nutritionists, myself included, think is too low--is about .4 gram per pound of body weight (i.e., 60 grams for a 150-pound woman).

Of course, athletes need more, as do muscular people, those under stress and those who are pregnant (Trish gets an extra couple of licks of Dairy Queen every day, and Sarah Pearl really appreciates that!).

For those good in math, there is a formula that seems to be appropriate. If you know your percentage of body fat, calculate your lean body weight (total weight minus body-fat pounds) and then multiply that by a number between .5 (if you’re completely sedentary) to .9 (if you’re a competitive athlete). The resulting figure tells you how many grams of protein you need per day.

Here is a simpler formula:

If you have no kidney problems and are not a diabetic, and are working out at least 3 times per week and those workouts are fairly intense, you need a minimum of 0.5-1.5 grams/pound of body weight of protein each day!

This means that a 200-pound man (or woman) exercising and weight lifting 3-4 times a week needs about 200 grams of protein each day as a part of his or her diet. If you're 65 years old or older, and weigh 150 pounds, and involved in an exercise program which consists of aggressive weight lifting, you require 75-100 grams of protein per exercise program and this will vary depending on the aggressiveness of weight training.

Remember, your protein and total caloric needs depend on your body type, amount of muscle, level of activity and exercise program. This will vary depending on the intensity of your training.

Your body can only use about 30-50 grams of protein at a time, so the total amount you require must be taken in throughout the day in the form of 4-7 meals. Moderate size meals, please.

If you are doing "serious" bodybuilding, we even recommend ingesting at least 15-20 grams at bedtime with a glass of water. This prevents a negative nitrogen balance (catabolism) from occurring during sleep.

The Best Sources of Quality Protein

Of course, it is not just the quantity of protein we ingest that is important, but the quality of the protein.

We use the term "bioavailability" to describe how efficiently the protein and its amino acids are used as a fuel and for building muscle. Some proteins tend to be more available to the body than others.

Generally, readily synthesized proteins are available in the form of egg whites, red meat, tuna and fish, milk or as whey or soy. These are the most popular food sources.

Unless you spend a lot of time preparing meals that are high in protein and low in fat and carbs, it is very difficult to get an adequate amount of protein, especially if you are into intense training.

Because of this, protein supplements may be an adjunct for you. These are generally available as protein shakes or protein bars.

Many or our clients ask us if they should use a protein powder. Protein powders are an easy way to get high-quality protein into your diet. They’re a great way to add variety to the menu of protein choices and are especially convenient when you don’t feel like sitting down to a meal. For people who aren’t hungry in the morning, but know they should eat something to keep them going, protein shakes are a great way to go. They’re also great as a snack after working out, and make a terrific mini-meal anytime.

What’s the best kind to use? It’s a toss-up between whey- and soy- based powders. The current process of rating protein is called the Protein Digestibility-Corrected Amino Acid Score, or PDCAA. Whey and soy have a nearly perfect PDCAA score of 1.0. Whey boosts the immune system, while soy is known to contain phytoestrogens. Many nutritionists recommend a mix of the two.

Please remember: if you consume too much protein (more than your body actually needs), it WILL be stored as fat. So, easy does it. But DO it!

In a recent study, researchers compared food guides from 12 different countries around the globe. Each country had a major message: get the majority of your calories from carbohydrates, with fewer calories from protein-rich foods, which are more often than not also rich in both saturated and unsaturated fat. Not one of the countries endorsed a high-protein (Atkins style) diet as a healthy eating pattern for its population. Hear a message here?

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