Saturday, June 14, 2008

Vegans, Vegetarians, and Proteins - Oh My!

The following is part one of a series from nutritionist Dipa Shah-Patel, MPH:

I am a nutritionist who is a vegetarian. If I had a dollar for every time I've ever heard "But how do you get enough protein if you don't eat meat?”, I'd be sitting pretty on a beach right now, enjoying my early retirement.

Getting enough protein as a vegetarian or vegan is not as hard as it may seem. With a little knowledge and planning, vegan and vegetarian diets can be well balanced and provide you with the nutrients your body needs. In fact, the American Dietetic Association states "plant sources of protein alone can provide adequate amounts of essential amino acids if a variety of plant foods are consumed and energy needs are met."

To calculate how much protein per day a healthy adult needs based on the Recommended Dietary Allowances, you can use the following formula:

Females: 0.8 x body weight (expressed in kilograms) = amount of protein in grams

Males: 1.0 x body weight (expressed in kilograms) = amount of protein in grams

For example, a 120-pound (55-kilogram) woman needs approximately 44 grams of protein per day, and a 160-pound (73-kilogram) man needs about 73 grams of protein per day. The average American consumes more than enough protein than he/she needs. Although the research is not conclusive, several studies have shown that diets that are high in protein may increase the risk of osteoporosis1 and kidney disease2.

Below is a list of foods and the amount of protein they contain:

Lentils (cooked)1 cup18 g
Kidney beans (cooked)1 cup13 g
Veggie patty1 patty12 g
Tofu, firm4 oz11 g
Quinoa (cooked)1 cup9 g
Almonds1/4 cup8 g
Peanut butter2 tbsp8 g
Soy milk, plain1 cup7 g
Eggs1 large6 g
Whole wheat bread1 slice3 g

Source: USDA Nutrient Database for Standard Reference, Release 18; 2005.

As you can see, with a little planning you can meet your protein needs from plant and grain sources. Below is a sample menu for a 138-pound woman who needs 50 g of protein per day:

Breakfast:1 cup oatmeal 6 g
1/2 cup cow's milk4 g
1/2 cup sliced
1 g
Lunch:Vegetarian sandwich (2 slices whole wheat bread, 1 slice cheddar cheese, vegetables)13 g
1 cup soymilk7 g
1 apple< 1 g
Dinner:1/2 cup lentils9 g
1/2 cup cooked spinach2.5 g
1/2 cup brown rice, cooked2.5 g
1/2 cup yogurt6 g
Total51 g

You may have noticed in the above examples that 1 egg and 1/4 cup of almonds appear to be about the same in their amount of protein. However, although they are similar in grams, they differ in protein composition. I'll discuss what the term "complete protein" means and how to get this in a vegan or vegetarian diet in part two.

1. Sellmeyer DE, Stone KL, Sebastian A, et al. A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Am J Clin Nutr. 2001;73:118-122.
2. Knight EL, Stampfer MJ, Hankinson SE, et al. The impact of protein intake on renal function decline in women with normal renal function or mild insufficiency. Ann Intern Med. 2003;138:460-467.

Dipa is available to answer any nutrition questions you may have. Email them to


Anonymous said...

Thank you for this informative article. I had no idea that lentils contain 18 grams of protein! I look forward to your next article.

-Vegetarian Science Teacher

Anonymous said...

Dipa, your article was very educational! I will definitely call you to plan my nutritional schedule! THANKS!

Matthew Ruscigno said...

Does Tryptophan make you sleepy? How much L-Arginine do I need per day? What does BCAA's mean? What if I only eat raw food? Do those extra enzymes mean I need less protein?

vikjay said...


This was so helpful! Thanks for posting :)

Anonymous said...

Hi Matt!,
Please send your email to and I will send you an email response answering all of your questions.

payal's eggless creations said...

i would like to contribute my knowledge wih you and would like to support you in spreading vegetarianism throught my blog..... it helps!!!!!