Article # 447. How to calculate your Protein needs

What is protein?

Protein is one of the basic building blocks of the human body, making up about 16 percent of our total body weight. Muscle, hair, skin, and connective tissue are mainly made up of protein. However, protein plays a major role in all of the cells and most of the fluids in our bodies. In addition, many of our bodies' important chemicals -- enzymes, hormones, neurotransmitters, and even our DNA -- are at least partially made up of protein. Although our bodies are good at “recycling” protein, we use up protein constantly, so it is important to continually replace it.

Proteins are made up of smaller units called amino acids. Our bodies can manufacture most of the needed amino aicds, but nine of them must be gotten from our diets. Animal proteins such as meat, eggs, and dairy products have all the amino acids, and many plants have some of them.

How much protein do we need?

Our protein needs depend on our age, size, and activity level. The standard method used by nutritionists to estimate our minimum daily protein requirement is to multiply the body weight in kilograms by .8, or weight in pounds by .37. This is the number of grams of protein that should be the daily minimum. According to this method, a person weighing 150 lbs. should eat 55 grams of protein per day, a 200-pound person should get 74 grams, and a 250-pound person should eat 92 grams.

Do athletes need more protein?

Yes. People engaging in endurance exercise (such as long distance running) or heavy resistive exercise (such as body building) can benefit from additional protein in their diets. The current recommendation is for these athletes to consume 1.2 to 1.7 grams of protein per day for each kilogram of body weight.

Do pregnant women need more protein?

Yes. The Institute of Medicine recommends that the minimum protein consumption for pregnant women be about 10 grams per day more than usual, though this is not as crucial in the first half of the pregnancy.

What happens if we don’t eat enough protein?

Unlike fat and glucose, our body has little capacity to store protein. If we were to stop eating protein, our body would start to break down muscle for its needs within a day or so.

Is it OK to eat a lot more protein than the minimum recommendations?

This is an important question for people on diets that are higher in protein than usual, as low-carb diets tend to be. In a review of the research, the National Academy of Sciences reported that the only known danger from high-protein diets is for individuals with kidney disease. After careful study, they recommend that 10 percent to 35 percent of daily calories come from protein. They point out that increased protein could be helpful in treating obesity. There is also accumulating evidence that extra protein may help prevent osteoporosis.

Extra protein can be broken down into glucose in a process called gluconeogenesis. On low-carb diets, this happens continually. One benefit of obtaining glucose from protein is that it is absorbed into the bloodstream very slowly, so it doesn’t cause a rapid blood sugar increase. However, some diabetics do find that too much protein causes an excessive blood sugar rise, and low-carbers sometimes find that as time goes on they do better with a moderate protein intake right than eating large amounts of protein.

Can Too Much Protein Cause Bad Breath?

Yes, actually, it can. If this is happening suddenly after a dietary change, excess protein could be the cause of bad breath.

What foods have the most protein?

Meat, fish, eggs, dairy products, legumes, and nuts all have substantial amounts of protein.

Here is other way of calculating your protein needs.

How to Calculate Your Protein Needs:

1. Weight in pounds divided by 2.2 = weight in kg
2. Weight in kg x 0.8-1.8 gm/kg = protein gm.

Use a lower number if you are in good health and are sedentary (i.e., 0.8). Use a higher number (between 1 and 1.8) if you are under stress, are pregnant, are recovering from an illness, or if you are involved in consistent and intense weight or endurance training.

Example: 154 lb male who is a regular exerciser and lifts weights
154 lbs/2.2 = 70kg
70kg x 1.5 = 105 gm protein/day

What if you're trying to build more muscle? Shouldn't you eat even more protein?

Not necessarily. There's evidence that bodybuilders, much like exercisers or athletes, do require more protein but that any more than double the RDA won't necessarily help you build more muscle. In one study, experts studied three groups of weight lifters: A low protein group (0.86 g/kg), a moderate protein group (1.40 g/kg) and a high protein group (2.40 g/kg) and found that, "There were no effects of varying protein intake on indexes of lean body mass."

In essence, the more you exercise, the greater your protein needs will be. However, taking it too far, for example more than doubling your protein intake, won't necessarily help you build more muscle.

Calculating Protein as a Percentage of Total Calories

Another way to calculate how much protein you need is by using daily calorie intake and the percentage of calories that will come from protein. To do this, you'll need to know how many calories your body needs each day.

First, find out what your Basal Metabolic Rate is by using a BMR calculator.

Next, figure out how many calories you burn through daily activity and add that number to your BMR. This gives you an estimate of how many calories you need to maintain your current weight.

After you've figured out your maintenance calories, next figure out what percentage of your diet will come from protein. The percentage you choose will be based on your goals, fitness level, age, body type and metabolic rate. Most experts recommend that your protein intake be somewhere between 15 and 30%. When you've determined your desired percentage of protein, multiply that percentage by the total number of calories for the day.

 Example:

For a 140lb female, calorie intake=1800 calories, protein=20%:
1800 x .20 = 360 calories from protein. Since 1 gram of protein = 4 calories, divide protein calories by four:
360/4 = 90 grams of protein per day.

No matter what your calculations are, remember that there are no magic foods or supplements that can replace the right training and the right diet. The foundation of any program, whether your goal is to lose weight or gain muscle, is a combination of strength training and a healthy diet that includes carbs, with a balance of protein and fat.