Guest Post by Bastyr University Masters of Nutrition Student Nancy Miller

You may sometimes wonder, “Am I getting enough protein in my diet?” but are perplexed if you look up online that you are supposed to eat around 10-35% of protein a day. What does that mean? Who divvies up their food according to percents? Maybe you read that you are supposed to get about 46–56 grams of protein per day (which is the recommendation, amounts depend on if you are a woman or a man). Does that mean you eat THAT much meat? While the average values work for many people, wouldn’t you like to know how to determine more precisely what you need and what you are actually getting from your food?

How Much Protein Is Enough?

It’s easy to forget that any food containing protein also includes many other components. For example, most animal products are roughly 75% water, 20% protein, and 5% fat, carbohydrates and other nutrients. So, if you eat a seven-ounce steak, you are not eating seven ounces of pure protein. This steak weighs 198 grams (converted into metric from ounces). Since most cuts of beef, for example, contain approximately seven grams of protein per ounce, a seven-ounce steak would contain roughly 49 grams of protein, which meets the general recommendation for daily protein needs for women.

How to Calculate Your Protein Needs:

But, we are all different sizes and shapes and have different needs. The above recommendations are for a general population. Let’s see how to calculate how much protein you as an individual need per day. This might seem a bit overwhelming but take it step by step and you can figure out what your unique protein needs are.

1.      Since the protein recommendations above are in grams, you will first need to convert your weight from pounds to kilograms:

    1. a.      Divide your weight in pounds (lb) by 2.2.
    2. b.      This is your weight in kilograms (kg)
  1. 2.      Multiply this number by 0.8 gm/kg (grams per kilogram).
    1. a.      This is your protein goal for most days in grams.
    2. b.      Use this number if you are mostly inactive but reasonably healthy.
  2. 3.       Divide this number by how many meals and snacks you plan for this day.
    1. a.      This the amount of grams of protein you have at each meal or snack.

Note: If you are physically active, sick, pregnant or very stressed, your protein needs will be higher, so keep that in consideration as you plan your protein needs. Your daily needs can increase up to 1.8 gm/kg per day.

For example, the calculation for a fairly healthy, 130-pound woman who works in an office is as follows:

  1. 130 lb divided by 2.2 kg = 59.1 kg
  2. 59.1 kg multiplied by 0.8 gm/kg = 47.3 g of protein PER DAY
  3. 47.3 g divided by 4 (for three meals and a snack) = 11.7 g of protein EACH MEAL (or divided out as you wish)

 

What does this look like in terms of real food?

Now you have an idea for what range of grams of protein you need each day. What do these numbers mean? How can you use them in meal planning? Well, a protein content of a few foods are:

  • ·    One slice of bacon has 3 grams of protein.
  • ·    A large egg has 6 grams protein.
  • ·    One cup of milk has 8 grams of protein.
  • ·    A 3-ounce piece of meat has about 21 grams of protein. If you don’t have a kitchen scale, this is about the size of a deck of cards.
  • ·    One cup of dry beans has about 16 grams of protein – but, remember, this one cup, when cooked, turns into about 3 cups, which might be more beans than you care to eat in a meal.

 

Using the calculations above as an example, this woman can choose to have an egg and some milk for total of 14 grams of protein. She might chose less protein with her lunch, such as have one cup of cooked beans, for a total of about five grams of protein. Her total so far is 19 grams of protein. She has 28.3 grams of protein left for the day. A 3-ounce steak would give her 21 more grams of protein. The rest is probably from various vegetables she had during the day. Voila. The daily protein needs of a 130-pound, mostly sedentary woman.

Various charts are available on the Internet which give you the grams of protein various foods contain. One can be found here: http://und.edu/student-life/dining/_files/docs/fact-sheets/protein.pdf

In conclusion, while we tend to think of protein as one single ingredient, it’s actually composed of a varying assortment and combinations of 20 amino acids (depending upon the food). Therefore, it’s important to remember that even though some vegetables, such as broccoli, contain protein (i.e., 2.6 grams in broccoli), they do not contain the full range of amino acids that are needed by our bodies. And, meat, poultry and fish provide different combinations of amino acids. And grains, other combinations. [Additionally, although vegetables are nutrient-dense, they do not provide all of the vitamins that are essential for our bodies, like B12 and vitamin D]. This is one reason you are encouraged to eat a varied diet containing animal products, vegetables, fruits, and whole grains.

 

References:

http://lowcarbdiets.about.com/library/blproteincalculators.htm

http://authoritynutrition.com/how-much-protein-per-day/

http://www.webmd.com/diet/healthy-kitchen-11/how-much-protein