Most vegetarians need roughly 0.8 grams of protein per kilogram of body weight per day, the same baseline recommendation as everyone else. For a 70 kg (154 lb) person, that works out to about 56 grams daily. But because plant proteins are digested a bit less efficiently than animal proteins, vegetarians generally benefit from aiming 20 to 40 percent higher than that baseline, landing closer to 1.0 to 1.1 g/kg per day.
The Baseline and Why Vegetarians Should Exceed It
The international Recommended Dietary Allowance for protein is 0.8 g per kg of body weight, regardless of age. That number was set using high-quality animal proteins as the reference. Plant proteins, with a few exceptions, score lower on digestibility measures and contain smaller amounts of essential amino acids, particularly leucine, the amino acid most responsible for triggering muscle repair and growth. Dairy products like whey score at the top of protein quality scales, while wheat sits near the bottom. Soy protein isolate and pea protein concentrate fall somewhere in between.
This doesn’t mean plant protein is inadequate. It means you need a bit more of it to get the same effect. Research published in the Journal of the International Society of Sports Nutrition puts a clear number on the gap: vegetarians and vegans generally need to consume about 20 to 40 percent more plant protein than an omnivore would need from animal sources to deliver comparable amounts of essential amino acids. For a sedentary adult, that shifts the practical target from 0.8 g/kg to roughly 1.0 g/kg per day.
Higher Needs for Active People
If you exercise regularly, the numbers climb. Endurance athletes (runners, cyclists, swimmers) are recommended to consume 1.2 to 1.7 g/kg per day, while strength athletes doing resistance training need 1.4 to 2.0 g/kg per day. Some research has tracked intake as high as 2.2 g/kg per day during intense training periods.
These ranges apply to all athletes, but vegetarians should aim for the upper end. A study comparing habitual vegans consuming 1.6 g/kg per day from whole foods and supplemental soy protein found they gained muscle and strength at the same rate as omnivores eating the same total amount of protein over 12 weeks. The key conditions: total daily protein hit at least 1.4 to 2.0 g/kg, each protein serving delivered at least 8 to 10 grams of essential amino acids, and leucine intake reached about 2 grams per serving. If you’re training seriously, those are the numbers to keep in mind.
Adjustments for Older Adults
Muscle mass naturally declines with age, and protein needs go up to compensate. The European Union Geriatric Medicine Society recommends that adults over 65 increase protein intake to at least 1.0 to 1.2 g/kg per day, up from the standard 0.8 g/kg. For those already experiencing muscle loss or at high risk, the Society for Sarcopenia, Cachexia, and Wasting Disease suggests going even higher, to 1.0 to 1.5 g/kg per day.
Plant protein specifically appears to matter here. A study of elderly adults in northern Taiwan found that those eating the least plant protein (below 5.8% of total calories) had more than double the risk of low muscle mass compared to those eating the most (9.4% or above). Muscle mass increased in a clear stepwise pattern as plant protein intake rose. So for older vegetarians, hitting the higher end of the protein range is not optional if preserving strength and independence is the goal.
Pregnancy and Lactation
During the second and third trimesters, protein needs increase by about 25 grams per day above your pre-pregnancy baseline. For a vegetarian already aiming for 1.0 g/kg, this typically brings the daily total to somewhere around 75 to 90 grams depending on body weight. Since this extra protein supports tissue growth and cell repair for both you and the baby, consistent intake throughout the day matters more than hitting one big number at dinner.
The Amino Acid Gap (and How to Close It)
The real issue with plant protein isn’t quantity. It’s that individual plant foods tend to be low in one or more essential amino acids. Grains and nuts are low in lysine. Corn is low in both lysine and tryptophan. Legumes fill those gaps neatly, which is why beans and rice have been dietary staples across cultures for thousands of years.
You don’t need to combine these foods in the same meal. Your body maintains a pool of amino acids that gets replenished throughout the day, so eating lentils at lunch and rice at dinner still covers you. What matters is variety across the day, not precise pairing at every sitting. Legumes (lentils, chickpeas, black beans) paired with grains (rice, oats, bread) over the course of a day will deliver a complete amino acid profile. Adding soy products, which are among the most complete plant proteins, makes this even easier.
Best Vegetarian Protein Sources
Not all plant foods are equal when it comes to protein density. Here’s how the major vegetarian staples stack up per 100 grams:
- Seitan: 25 g protein. Made from wheat gluten, it’s the most protein-dense plant food by weight. However, it’s low in lysine, so pair it with legume-based foods over the course of the day.
- Tempeh: 20.7 g protein. Fermented soybeans with a complete amino acid profile and good digestibility.
- Tofu: 16.5 g protein. Another soy product with a strong amino acid profile, versatile in cooking.
- Cooked lentils: 8.8 g protein. Lower per 100 grams than soy products, but easy to eat in large portions (a cup of cooked lentils is roughly 200 grams, delivering about 18 grams).
Vegetarians who include dairy and eggs have an easier time hitting their targets. One large egg provides about 6 grams of highly digestible protein, and Greek yogurt delivers around 10 grams per 100 grams. These animal-sourced proteins score highest on digestibility scales and provide generous amounts of leucine, making them especially useful for older adults and athletes.
Putting It All Together
Here’s a quick reference for daily protein targets in grams per kilogram of body weight, with the vegetarian adjustment already built in:
- Sedentary adults: 1.0 to 1.1 g/kg
- Recreationally active adults: 1.2 to 1.4 g/kg
- Endurance athletes: 1.4 to 1.7 g/kg
- Strength athletes: 1.6 to 2.0 g/kg
- Adults over 65: 1.2 to 1.5 g/kg
- Pregnant (2nd/3rd trimester): add 25 g/day to your baseline
To convert your weight: divide your weight in pounds by 2.2 to get kilograms, then multiply by the appropriate number. A 150 lb recreational exerciser, for example, would calculate 68 kg × 1.3 g/kg = roughly 88 grams per day. Spread that across three to four meals featuring legumes, soy products, whole grains, and (if lacto-ovo) dairy or eggs, and you’ll cover both the quantity and the amino acid quality your body needs.