How much protein do I need per day?

A healthy adult needs at least 0.8 g of protein per kilogram of body weight a day (about 0.36 g per pound). If you train, the evidence points to 1.6 to 2.2 g per kg (0.7 to 1 g per pound), especially if you want to build muscle or keep it while losing weight. Spread it over 3 or 4 meals of roughly 20 to 40 g each.

Written by the SUMAAI team · Professional review: coming soon · Updated October 22, 2026

What protein is and what it does

Protein is one of the three macronutrients, along with carbohydrates and fat. It's made of amino acids, the building blocks your body uses to build and repair muscle, skin, enzymes, hormones and immune defenses. Some amino acids your body can't make, so they have to come from food.

Your tissues turn over every day, which is why you need protein every day. When you strength train, enough protein helps muscle recover and grow. When you lose weight, it helps make sure what you lose is mostly fat rather than muscle. Protein also tends to be more filling than the same calories from other foods, which helps when you're in a calorie deficit.

Each gram of protein provides about 4 calories, the same as carbohydrates.

How much protein you need

Protein needs are worked out per kilogram of body weight, not as one number for everyone. To convert, divide pounds by 2.2 to get kilograms:

• 0.8 g/kg is a minimum, not everyone's target. It's the Recommended Dietary Allowance (RDA) set by the US National Academies for healthy adults, and the European Food Safety Authority (EFSA) lands on almost the same figure: 0.83 g/kg. It covers the needs of nearly all healthy people, but it isn't designed for building muscle.
• If you train, 1.6 to 2.2 g/kg. The International Society of Sports Nutrition (ISSN) considers 1.4 to 2.0 g/kg a day enough for most people who exercise. A meta-analysis of 49 trials (Morton and colleagues, 2018) found the benefit for muscle mass levels off at around 1.6 g/kg, with an upper bound reaching 2.2 g/kg, which is where that range comes from.
• Losing weight while training? Aim for the upper end. In a calorie deficit your body tends to lose some muscle too, and the ISSN notes that more protein may be needed during those periods to hold on to it.
• After 65, the PROT-AGE expert group recommends at least 1.0 to 1.2 g/kg for healthy older adults, and more for those who exercise.

The factors SUMAAI uses

The app sets your protein target with these factors:

• You don't train: 1.2 g/kg, a little above the 0.8 minimum.
• You train and want to lose weight: 2.0 g/kg, to protect your muscle while you lose.
• You train and want to maintain or gain weight: 1.8 g/kg.

For the app, "you train" means your activity level is light or higher, or your goal is to build muscle. Protein also never goes above 35% of your calories, the top of the National Academies' acceptable range (10% to 35% of energy). That cap only kicks in if you weigh a lot and eat few calories.

Protein calculator

How to spread it across the day

Your body doesn't store protein "in reserve" the way it stores fat, so it pays to spread it out rather than eat most of it at dinner:

• The ISSN recommends servings of 20 to 40 g of protein (about 0.25 g per kg) every 3 to 4 hours.
• A 2018 review by Schoenfeld and Aragon suggests about 0.4 g per kg per meal over at least 4 meals to reach 1.6 g/kg a day.
• After a hard workout, include protein in your next meal.

An example: at 154 lb (70 kg), training and losing weight, the target is about 140 g. Over 4 meals that's about 35 g each: eggs with beans at breakfast, chicken with rice and vegetables at lunch, Greek yogurt in the afternoon and fish with salad at dinner.

How much protein is in common foods

Approximate amounts; they vary by brand and preparation, so check the label when there is one:

Tortillas, rice and bread add a little protein too, but not much for their calories.

Plant protein

You can hit your target without meat. The best plant sources are legumes (beans, lentils, chickpeas, fava beans), soy and soy foods (tofu, soy milk, textured soy protein), and to a lesser extent seeds and peanuts.

• Mix sources through the day: legumes and grains complement each other, like beans with tortillas or rice with lentils. They don't need to be on the same plate.
• Plan for a bit more volume: plant sources also bring carbs and fiber, so the same protein comes with a bigger plate.
• Soy is one of the few plant proteins with all the essential amino acids in good amounts.

Myths and FAQ

Does a high-protein diet damage your kidneys?

In healthy people, the evidence says no. A 2018 meta-analysis compared higher-protein diets with normal ones and found no difference in kidney function among healthy adults. If you already have kidney disease, it's a different story: your doctor or dietitian will tell you how much protein is right for you.

Does more protein mean more muscle?

No. In the meta-analysis by Morton and colleagues, the muscle-building benefit leveled off at around 1.6 g per kg a day. Eating more won't hurt a healthy person, but those extra calories don't turn into extra muscle, and they crowd out other foods.

Can your body only use 30 g of protein per meal?

That's an oversimplification. Your body absorbs all the protein you eat; the open question is how much of it goes to building muscle at each meal. A review by Schoenfeld and Aragon suggests about 0.4 g per kg per meal, across at least 4 meals, as a practical way to spread it out.

Do I need protein powder?

No. If you reach your target with food, you don't need it. Powder is just a convenient way to add 20 to 25 g when your meals fall short; check the label, because it varies a lot between brands.

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