Protein forms many body structures, including muscles, skin, and hair. It also forms enzymes that catalyze chemical reactions throughout your body. Protein molecules are composed of amino acids.

How much protein do we need?

During World War II, Lydia J. Roberts, Hazel Stiebeling, and Helen S. Mitchell were part of a committee established by the United States National Academy of Sciences in order to investigate nutrition issues. They surveyed all available data, created allowances for calories and 8 nutrients, and submitted them to experts for review. The final set of guidelines, called RDAs for Recommended Dietary Allowances, were accepted in 1941. The allowances were meant to provide superior nutrition for military personnel and civilians, including those needing food assistance, so they included a “margin of safety.” Because of food rationing during the war, the food guides also took food availability into account. The committee was renamed the Food and Nutrition Board in 1941, and they subsequently revised the RDAs every five to ten years. In the early 1950s, United States Department of Agriculture nutritionists made a new set of guidelines that also included the number of servings of each food group in order to make it easier for people to receive their RDAs of each nutrient.

The Reference Daily Intake or Recommended Daily Intake (RDI) is the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97–98% of healthy people. The RDI is used to determine the Daily Value (DV) of foods, which is printed on nutrition facts labels in the United States and Canada, which is regulated by the Food and Drug Administration (FDA), and Health Canada. The RDI is based on the older Recommended Dietary Allowance (RDA) from 1968, and is still used for nutrition labeling.

The RDA recommends that we take in 0.8 grams of protein for every kilogram that we weigh (or about 0.36 grams of protein per pound that we weigh). For me, that would come to 40.32 grams. This recommendation includes a generous safety factor for most people.

The Dietary Reference Intake (DRI) was introduced in 1997 in order to broaden the RDAs. The DRI is a system of nutrition recommendations from the Institute of Medicine (IOM) of the U.S. National Academy of Sciences. Both the United States and Canada use the DRI system. The DRI values are not currently used in nutrition labeling, where the older RDIs are still used.

You can calculate your DRI for protein and other nutrients here. My DRI for protein is 41 grams (pretty close to the old RDA); my husband’s DRI is 73 grams. For me, that means that just 12% of my calories need to come from protein; for my husband, it’s less than 11%. And that need wouldn’t change much if we were more or less active than we are now.  Athletes do not need much more protein than the rest of us.

So am I able to meet that requirement for protein on a vegan diet? You bet. My typical daily food intake looks like this:

Breakfast: steel-cut oats with berries and ground flax seeds

Morning snack: fruit

Lunch: huge salad of baby spinach, grated carrots, radishes, beets, sunflower seeds, and Pomegranate Vinaigrette, plus home-made vegetable and legume soup, such as Lentil Minestrone

Afternoon snack: more fruit

Dinner: brown rice, legumes, and steamed kale

I added all this up in the portions I actually eat, and it came out to 1,431 calories and over 62 grams of protein (14% of the calories). There’s plenty of room in there for a little organic dark chocolate and red wine.

So, without even trying, I get 125% of the protein I need, all from delicious fruits, vegetables, and seeds. In fact, if I ate nothing but 4.85 pounds of baked potatoes per day, I would get enough calories (2,068) and more than enough protein (46 grams). I’d get even more protein if I ate nothing but 14 2/3 cups of cooked broccoli per day: 2,041 calories and over 54 grams of protein. If I could manage to pack in 14 1/3 cups of cooked brown rice in a day, I’d get my 2,041 calories and over 72 grams of protein.

As you can see, it is very easy for a vegan diet to meet the recommendations for protein. Nearly all vegetables, beans, grains, nuts, and seeds contain some, and often plenty, protein. Many fruits, plus refined sugars, fats, and alcohol are low in protein, so if you’re living on bananas, cola, frosting, or whiskey, you probably aren’t getting enough protein. However, vegans who eat varied diets containing vegetables, beans, grains, nuts, and seeds rarely have any difficulty getting enough protein as long as their diet contains enough calories to maintain their weight. The DRI calculator can help you determine special requirements during pregnancy, lactation, infancy, and childhood.

With protein, as with chocolate and wine, more is not necessarily better. Animal protein and protein supplements are expensive, unnecessary, and even harmful for some people. There are no known health advantages to consuming a high-protein diet. In fact, diets that are high in protein, especially animal protein, may even increase the risk of osteoporosis  and kidney disease.