(Where do you get your) Protein (?)

(Last updated June, 2010.)

Contents

• Introduction
• Protein Recommendations
• Protein Content of Common Vegan Foods
• Vegans Might Not Meet Protein Needs If...
• High Quality Protein
• Amino Acids in Common Foods
  • Protein & Amino Acid Calculation Aids
• Related Links
• References

Introduction

It was once believed that vegetarians (and vegans) needed to combine protein sources at each meal to get "complete protein." Now we know that protein combining at each meal is not necessary. In their 2009 Position Paper on Vegetarian Diets, The American Dietetic Association states:

Table 1. Protein Recommendations for Young Vegans
Age (yrs)	Females (g/day)	Males (g/day)
1 - 2	18-19	18-19
2 - 3	18-21	18-21
4 - 6	26-28	26-28
7 - 10	31-34	31-34
11 - 14	51-55	50-54
15 - 18	50-55	66-73

"Plant protein can meet requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults, thus complementary proteins do not need to be consumed at the same meal."

When I became vegan in 1988, the most common question I got was, "Where do you get your protein?" It's now been about 20 years since protein in vegan diets was determined to be a non-issue by nutrition researchers. Yet today, one of the most common questions I get is, "Where do you get your protein?"

Protein Recommendations

Experts recommend that adult vegans eat .4 g of protein per day for every pound of healthy body weight (1). Recommendations for younger vegans (2) are shown in Table 1.

Protein Content of Common Vegan Foods

The plant foods highest in protein are legumes (beans, peanuts, soyfoods such as tofu) and nuts, but grains and vegetables also contribute significant amounts.

Table 2. Protein Content of Common Vegan Foods
Food	Serving	Protein (g)
Naturade soy protein powder	1/3 Cup	23 g
Naturade soy-free protein powder	1/3 Cup	22 g
Seitan	3 oz	22.5
Tofu	1/2 Cup	8 - 11
Veggie dog/burger	1	6 - 18
Tempeh*	3 oz	15.5
Soybeans*	1/2 Cup	14.3
Texturized soy protein	1/2 Cup	11
Soymilk	1 Cup	5 - 10
Lentils*	1/2 Cup	8.9
Quinoa	1 C (cooked)	8.1
Peanut butter	2 Tablespoons	8
Chickpeas*	1/2 Cup	7.5
Refried beans*	1/2 Cup	6.9
Sunflower seeds	1/4 Cup	6.2
Oatmeal*	1 Cup, instant	5.9
Brown rice*	1 Cup	5
Broccoli*	1 Cup chopped	4.6
Potato, baked	1 medium	4.5
Walnuts	1/2 oz (7 halves)	4.3
White rice*	1 Cup	4.1
Almonds	1/2 oz (12 kernels)	3
Kale*	1 Cup chopped	2.5
Taco shell	1 medium	1
Carrot	1 med	0.6
*Cooked

Click here to check the USDA National Nutrient Database for the content of protein or other nutrients in foods.

You can see from these vegan meal plans that it's not too difficult to meet protein needs on a vegan diet. See Table 2 for the protein content of many common vegan foods.

Here are some more protein links that might be of interest:

• Response to CCF about Protein for Vegan Teenagers
• How can I get plant protein without eating soy?

Vegans Might Not Meet Protein Needs If...

Vegans might not meet their protein needs, resulting in a loss of muscle mass and/or reduced immunity, if:

• Food intake does not meet energy needs such as in cases of anorexia nervosa, depression, poverty, lack of appetite due to illness, or dieting.
• Higher-protein plant foods are not included in sufficient amounts. This can happen when:
  • Most foods eaten are low-protein, junk food such as French fries, potato chips, and soda.
  • Protein is believed to be unimportant and/or higher protein foods are avoided (such as in some fruitarian or raw food diets).
  • Legumes are avoided. (Other high-protein foods should be used.)

High Quality Protein

Proteins are made out of chains of amino acids. Some amino acids can be made by the body (generally from other amino acids), but some cannot. The ones that cannot are known as "essential" or "indispensable."

Twenty amino acids are used to build protein, but they are not the only amino acids. Carnitine and taurine are amino acids that our bodies make and use, but which are not building blocks of protein. The discussion below is limited to the amino acids needed to build proteins.

Because some amino acids are essential, the RDA for amino acids should be as important as the RDA for protein. But because the RDA for protein takes into account the RDA for amino acids, the RDA for amino acids is rarely mentioned. As it turns out, essential amino acids are found in fairly consistent amounts in various foods and, thus, the RDA for protein is calculated with typical diets in mind.

Proteins in the human body tend to have a consistent percentage of the essential amino acids. The percentages of essential amino acids in both animal products and soy products closely mimic those found in human proteins. Non-soy plant proteins have a lower percentage of at least one amino acid (in particular, beans are lower in methionine and grains are lower in lysine).

When Frances Moore Lappe wrote her book, Diet for a Small Planet, in the early 1970s, she popularized the idea of combining proteins at each meal. By mixing beans and grains, you can make sure that you are getting both methionine and lysine at each meal. We now know that the liver can store the various essential amino acids and so it's not critical to combine different protein sources at each meal.

Some people are under the impression that some plant proteins are devoid of at least one essential amino acid. The truth is that all plant proteins have some of every essential amino acid (see Table 3).

There have not been many studies measuring the protein or amino acid status of vegans. Because vegans tend to have good health and vegan diets normally meet the essential amino acid RDA, it is assumed that amino acid and protein intake is a non-issue for those on a typical vegan diet. But, since questions often arise, Table 3 shows the RDA for protein and amino acids, along with the content of commont plant foods.

The RDA for protein is supposed to cover the needs of 97.5% of the population, but the average adult between 19 and 50 years old needs only .66 g per kg of ideal body weight per day (the average vegan would therefore need .73 g per kg) (1). Most people will not need to meet the RDA to meet their protein needs. Because the amino acids in whole plant foods are harder to extract due to the indigestibility of some plant cell walls, vegans need about 10% more protein than non-vegetarians. For that reason, I have inflated the RDA for vegans by 10%. Also note that the Food and Nutrition Board, who sets the RDAs, says, "In conclusion, available evidence does not support recommending a separate requirement for vegetarians who consume complementary mixtures of plant proteins[.]" However, because there is still a debate about this for vegans, I have inflated the numbers as described above just to be safe.

Amino Acids in Common Foods

In Table 3, the essential amino acid methionine is paired with the non-essential cysteine. Similarly, the essential amino acid phenylalanine is paired with the non-essential tyrosine. That is because the RDA is calculated for these pairs of amino acids together, assuming there are similar ratios in different foods. In the plant foods I surveyed, there are about equal amounts of methionine and cysteine, and usually more phenylalanine than tyrosine. So, there is no reason to be concerned that plant foods are not providing a high ratio of methionine and phenylalanine.

Protein & Amino Acid Calculation Aids

1. In this downloadable Excel spreadsheet, you can enter different amounts of selected foods to get an idea of how close you are to meeting the RDA: Amino Acid Spreadsheet
   
   Again, there is no reason to worry if you find that your diet doesn't completely meet the RDA.
2. In the box below, if you enter your weight and click the button, Table 3 will show how much of any given food you need to meet the RDA for protein and amino acids. Of course we are not suggesting you get all your amino acids from one food, but it can give you an idea of what is required.

Enter Ideal Body Weight:

lbs kg

Table 3. Protein & Amino Acid Content of Plant Foods Number of Servings to Meet the RDA for a Plant-Only Diet for a 140 lb Person
USA Recommended Dietary Allowance (RDA)
	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
RDA (per kg of IBW)	0.8	14	19	42	38	19	33	20	5	24
Vegan RDA (per kg of IBW)	0.88	15	21	46	42	21	36	22	6	26
Vegan RDA for 140 lb. person	56	980	1330	2940	2660	1330	2310	1400	350	1680
Protein Powders
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Naturade Soy Protein Serving: 0.33 cup (28 g)	24.0	618	1178	1939	1552	640	2184	912	305	1157
Number of servings to meet RDA	2.3	1.6	1.1	1.5	1.7	2.1	1.1	1.5	1.1	1.5
Naturade Soy-Free Protein Serving: 0.33 cup (28 g)	22.0	533	1182	1785	1455	445	1957	918	228	1115
Number of servings to meet RDA	2.5	1.8	1.1	1.6	1.8	3.0	1.2	1.5	1.5	1.5
Soy
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Edamame Serving: 1.00 cup (155 g)	16.7	414	465	1155	1155	411	1277	513	195	502
Number of servings to meet RDA	3.4	2.4	2.9	2.5	2.3	3.2	1.8	2.7	1.8	3.3
Soy Milk Serving: 1.00 cup (245 g)	9.2	174	353	590	439	213	644	277	105	345
Number of servings to meet RDA	6.1	5.6	3.8	5.0	6.1	6.2	3.6	5.1	3.3	4.9
Tofu - firm Serving: 1.00 cup (252 g)	20.6	567	1119	1835	1164	353	2026	1036	310	1147
Number of servings to meet RDA	2.7	1.7	1.2	1.6	2.3	3.8	1.1	1.4	1.1	1.5
Nuts
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Almonds Serving: 22.00 kernal (28 g)	6.2	174	204	433	177	139	494	200	56	236
Number of servings to meet RDA	9.0	5.6	6.5	6.8	15.0	9.6	4.7	7.0	6.3	7.1
Cashews Serving: 1.00 oz (28 g)	4.3	113	207	364	232	158	363	168	67	295
Number of servings to meet RDA	13.0	8.7	6.4	8.1	11.5	8.4	6.4	8.3	5.2	5.7
Pistachios Serving: 49.00 kernal (28 g)	6.1	149	265	458	339	205	435	198	81	365
Number of servings to meet RDA	9.2	6.6	5.0	6.4	7.8	6.5	5.3	7.1	4.3	4.6
Walnuts Serving: 13.00 halves (28 g)	4.3	111	177	332	120	126	317	169	48	213
Number of servings to meet RDA	13.0	8.8	7.5	8.9	22.2	10.6	7.3	8.3	7.3	7.9
Legumes
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Black Beans Serving: 1.00 cup (172 g)	15.2	425	673	1218	1046	394	1254	642	181	798
Number of servings to meet RDA	3.7	2.3	2.0	2.4	2.5	3.4	1.8	2.2	1.9	2.1
Garbanzos - Chick Peas Serving: 1.00 cup (164 g)	14.5	400	623	1035	973	385	1140	540	139	610
Number of servings to meet RDA	3.9	2.5	2.1	2.8	2.7	3.5	2.0	2.6	2.5	2.8
Kidney Beans Serving: 1.00 cup (177 g)	15.4	428	678	1227	1053	396	1262	646	182	804
Number of servings to meet RDA	3.6	2.3	2.0	2.4	2.5	3.4	1.8	2.2	1.9	2.1
Lentils Serving: 1.00 cup (198 g)	17.9	503	772	1295	1247	386	1358	640	160	887
Number of servings to meet RDA	3.1	1.9	1.7	2.3	2.1	3.4	1.7	2.2	2.2	1.9
Peanut Butter Serving: 2.00 T (32 g)	8.0	204	284	523	290	202	746	276	78	339
Number of servings to meet RDA	7.0	4.8	4.7	5.6	9.2	6.6	3.1	5.1	4.5	5.0
Peanuts Serving: 28.00 kernal (28 g)	6.7	170	236	435	241	168	621	230	65	282
Number of servings to meet RDA	8.4	5.8	5.6	6.8	11.0	7.9	3.7	6.1	5.4	6.0
Pinto Beans - refried Serving: 1.00 cup (252 g)	13.8	386	610	1104	950	360	1139	582	164	723
Number of servings to meet RDA	4.1	2.5	2.2	2.7	2.8	3.7	2.0	2.4	2.1	2.3
Grains
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Bread - white Serving: 1.00 slice (25 g)	2.1	45	81	145	56	79	160	61	24	90
Number of servings to meet RDA	26.7	21.8	16.4	20.3	47.5	16.8	14.4	23.0	14.6	18.7
Bread - whole wheat Serving: 1.00 slice (28 g)	2.7	63	105	188	85	103	211	83	39	124
Number of servings to meet RDA	20.7	15.6	12.7	15.6	31.3	12.9	10.9	16.9	9.0	13.5
Buckwheat - groats roasted Serving: 1.00 cup (168 g)	5.7	133	213	356	289	171	327	217	82	291
Number of servings to meet RDA	9.8	7.4	6.2	8.3	9.2	7.8	7.1	6.5	4.3	5.8
Corn Serving: 1.00 cup (82 g)	5.4	150	218	588	232	158	460	218	38	314
Number of servings to meet RDA	10.4	6.5	6.1	5.0	11.5	8.4	5.0	6.4	9.2	5.4
Flour Tortilla Serving: 1.00 med (46 g)	4.0	90	141	276	98	154	322	113	49	164
Number of servings to meet RDA	14.0	10.9	9.4	10.7	27.1	8.6	7.2	12.4	7.1	10.2
Oatmeal - boiled Serving: 1.00 cup (234 g)	5.9	126	271	505	316	335	568	225	236	374
Number of servings to meet RDA	9.5	7.8	4.9	5.8	8.4	4.0	4.1	6.2	1.5	4.5
Quinoa - cooked Serving: 1.00 cup (185 g)	8.1	235	290	483	442	295	496	242	96	342
Number of servings to meet RDA	6.9	4.2	4.6	6.1	6.0	4.5	4.7	5.8	3.6	4.9
Rice - brown, med grain Serving: 1.00 cup (195 g)	4.5	115	191	372	172	156	402	166	58	265
Number of servings to meet RDA	12.4	8.5	7.0	7.9	15.5	8.5	5.7	8.4	6.0	6.3
Rice - white, med grain Serving: 1.00 cup (186 g)	4.4	104	192	366	160	195	385	158	52	270
Number of servings to meet RDA	12.7	9.4	6.9	8.0	16.6	6.8	6.0	8.9	6.7	6.2
Spaghetti - white Serving: 1.00 cup (140 g)	6.7	136	258	456	127	292	498	176	85	284
Number of servings to meet RDA	8.4	7.2	5.2	6.4	20.9	4.6	4.6	8.0	4.1	5.9
Spaghetti - whole wheat Serving: 1.00 cup (140 g)	7.5	175	290	510	165	275	566	200	97	323
Number of servings to meet RDA	7.5	5.6	4.6	5.8	16.1	4.8	4.1	7.0	3.6	5.2
Fruit
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Apple Serving: 1.00 med (138 g)	0.4	7	8	18	17	2	9	8	1	17
Number of servings to meet RDA	140.0	140.0	166.3	163.3	156.5	665.0	256.7	175.0	350.0	98.8
Banana Serving: 1.00 med (118 g)	1.3	91	33	80	59	20	69	33	11	55
Number of servings to meet RDA	43.1	10.8	40.3	36.8	45.1	66.5	33.5	42.4	31.8	30.5
Orange Serving: 1.00 med (131 g)	1.2	24	33	30	62	39	62	20	12	52
Number of servings to meet RDA	46.7	40.8	40.3	98.0	42.9	34.1	37.3	70.0	29.2	32.3
Strawberries - whole Serving: 1.00 cup (144 g)	1.0	17	23	49	37	12	59	29	12	27
Number of servings to meet RDA	56.0	57.6	57.8	60.0	71.9	110.8	39.2	48.3	29.2	62.2
Vegetables
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Baked Potato Serving: 1.00 med (173 g)	4.3	93	175	260	263	121	351	157	67	244
Number of servings to meet RDA	13.0	10.5	7.6	11.3	10.1	11.0	6.6	8.9	5.2	6.9
Broccoli - chopped, boiled Serving: 1.00 cup (156 g)	3.6	82	180	216	234	88	244	152	48	212
Number of servings to meet RDA	15.6	12.0	7.4	13.6	11.4	15.1	9.5	9.2	7.3	7.9
Romaine Lettuce - shredded Serving: 1.00 cup (56 g)	0.7	16	58	54	58	22	60	42	6	48
Number of servings to meet RDA	80.0	61.3	22.9	54.4	45.9	60.5	38.5	33.3	58.3	35.0
Seaweed
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Spirulina - dried Serving: 1.00 tbsp (7 g)	4.0	76	225	346	212	126	375	208	65	246
Number of servings to meet RDA	14.0	12.9	5.9	8.5	12.5	10.6	6.2	6.7	5.4	6.8
Animal
Food	PRO	HIS	ISO	LEU	LYS	MET CYS	PHE TYR	THR	TRY	VAL
Beef - ground, 15% fat, pan-broiled Serving: 3.00 oz (85 g)	20.9	681	924	1631	1733	745	1459	811	108	1028
Number of servings to meet RDA	2.7	1.4	1.4	1.8	1.5	1.8	1.6	1.7	3.2	1.6
Chicken - roasted Serving: 1.00 leg (52 g)	14.1	417	708	1028	1152	562	1004	583	158	684
Number of servings to meet RDA	4.0	2.4	1.9	2.9	2.3	2.4	2.3	2.4	2.2	2.5
Egg - hard boiled Serving: 1.00 large (50 g)	6.3	149	343	537	452	342	591	302	76	384
Number of servings to meet RDA	8.9	6.6	3.9	5.5	5.9	3.9	3.9	4.6	4.6	4.4
Milk - 2% fat Serving: 1.00 cup (244 g)	8.1	178	447	808	569	464	768	251	98	532
Number of servings to meet RDA	6.9	5.5	3.0	3.6	4.7	2.9	3.0	5.6	3.6	3.2
Tuna Serving: 3.00 oz (85 g)	21.7	638	999	1762	1992	874	1579	950	243	1117
Number of servings to meet RDA	2.6	1.5	1.3	1.7	1.3	1.5	1.5	1.5	1.4	1.5
PRO = Protein |   HIS = Histidine |   VAL = Valine |   MET CYS = Methionine + Cysteine ISO = Isoleucine |   THR = Threonine |   LEU = Leucine |   PHE TYR = Phenylalanine + Tyrosine TRY = Tryptophan |   LYS = Lysine |   IBW = Ideal Body Weight Protein is measured in grams   |   Amino acids are measured in mg

References

Sources:

• Amino acid RDAs were taken from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2002) by the Food and Nutrition Board (FNB) of the Institute of Medicine. Link
• The protein and amino acid content of foods was taken from the USDA and Naturade protein powder labels.
• Amino acid RDAs were taken from Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2002) by the Food and Nutrition Board (FNB) of the Institute of Medicine. Link
• The protein and amino acid content of foods was taken from the USDA and Naturade protein powder labels.

Related Links

Plasma amino acids - normal levels reference.

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References