How Much Protein Do You Need Per Day? A Simple Guide to Daily Protein Intake

Protein has become one of the most talked-about nutrients in health and fitness, but figuring out how much protein do you need per day can feel confusing, especially with wide disagreement between official guidelines and what many researchers now recommend. Is 0.8 grams per kilogram really enough? Do athletes need double that? What about older adults? This guide breaks down what the official RDA actually means, what leading protein researchers say it's missing, and how to calculate a number that fits your body and goals.

What is the Current Official Protein Recommendation?

If you're asking how much protein do you need per day in the most official sense, the answer starts here. In the United States and Canada, the current Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day (about 0.36 grams per pound), a figure set by the Institute of Medicine's Dietary Reference Intakes.1 For a 70 kg (154 lb) individual, this comes to about 56 g protein/day.

What Does the RDA Really Measure?

This is the key piece of information that gets overlooked: The RDA was intended to be the bare minimum required to avoid protein deficiency in a sedentary individual, not necessarily the amount of protein needed to maintain good muscle health, healthy aging, or optimize body composition. As Dr. Donald Layman, Professor Emeritus of Food Science and Human Nutrition at the University of Illinois Urbana-Champaign, has pointed out, "The RDA should be used only as a guide for the minimum protein needed for survival, not an optimal level of protein intake."² Layman has been studying dietary protein and muscle protein synthesis for over 40 years.²

Why Most Scientists Believe That RDA Should Be Increased

This isn't an alternate opinion; it's a well-documented position among researchers who study exactly how much protein you need per day for more than just avoiding deficiency.

The Argument in Favor of Increased Protein Consumption

Dr. Stuart M. Phillips is a professor in Kinesiology and the director of the Physical Activity Centre of Excellence at McMaster University. In 2016, he co-authored a study published in the journal Applied Physiology, Nutrition, and Metabolism entitled "Protein 'requirements' beyond the RDA: implications for optimizing health."³ Phillips et al. found a large body of evidence confirming that increased consumption of high-quality protein helps with healthy aging, appetite control, weight maintenance, and athletic performance, often exceeding 0.8 g/kg.³ It also may help with preventing age-related muscle loss (sarcopenia).

How Much Should the Experts Actually Recommend?

Now that you know the research, here's how to turn it into an actual number- the fastest way to answer how much protein you need per day for your specific body and goals.

This is not an exact number because these are just the ranges based on the research of Phillips et al. It is different for everyone due to differences in activity levels and age.3

Why Timing and Quality of Protein Also Matter

The total number of grams per day isn't the only important element; timing and quality of the protein intake are also factors.

Leucine Threshold

A large part of the studies has been inspired by research by Dr. Donald Layman about an amino acid called leucine, which triggers muscle protein synthesis.² The research of Dr. Donald Layman shows that most adults need about 30 grams of high-leucine protein intake per meal to properly activate the mechanism of muscle protein synthesis. It is also stated that a balanced intake of protein in 3 meals is better for muscle preservation than a high intake at dinner time.⁴

Quality of Protein

Different protein foods have varying qualities. Animal protein foods, such as egg whites, dairy products, meat, and fish, are relatively higher in leucine content and more efficient compared to plant-based proteins, such as beans, lentils, and cereals, which are low in leucine per gram of food intake. Thus, vegetarian and vegan people will need slightly higher amounts of these foods to meet their needs.⁴

How to Calculate Your Own Protein Target

Now that you know the research, here's how to turn it into an actual number, the fastest way to answer how much protein do you need per day for your specific body and goals.

Step 1: Find Your Body Weight in Kilograms

If you know your weight in pounds, divide by 2.2 to get kilograms. For example, 160 lbs ÷ 2.2 = ~73 kg.

Step 2: Choose a Multiplier Based on Your Goal

Use the table above as a guide: 0.8 g/kg if fully sedentary, 1.2–1.6 g/kg for general activity or weight management, and 1.6–2.2 g/kg if you strength train regularly.

Step 3: Multiply to Get Your Daily Target

A 73 kg moderately active adult aiming for 1.4 g/kg would need roughly 102 grams of protein per day, about 34 grams per meal across three meals, which aligns with Layman's research on the per-meal leucine threshold.²

Step 4: Spread It Out Throughout Your Day

Instead of consuming most of your daily protein at once, try to keep an equal balance between breakfast, lunch, and dinner to optimize muscle protein synthesis.⁴

Signs You Are Probably Not Consuming Enough Protein

• Hunger or cravings after eating a meal

• Unexpected feelings of tiredness or difficulty recovering from physical activity

• Lack of muscle maintenance, particularly with advancing age or during periods of weight loss

• Weak nails or hair, or difficulty healing wounds

If you notice several of these signs, it may be worth tracking your intake for a few days to see whether you're actually hitting how much protein do you need per day, or falling short of it.

Frequently Asked Questions

So how much protein do you need per day if you're wondering about upper limits?

For most healthy individuals, moderate-high protein intakes (up to approximately 2-2.2 g/kg) are generally deemed to be safe, according to contemporary studies; however, individuals who suffer from renal problems ought to ask their doctor for advice before drastically boosting protein consumption, as kidneys filter the metabolic products of proteins.

Am I required to increase my protein consumption if I am planning to lose weight?

Yes, how much protein do you need per day typically goes up, not down, during weight loss. Many researchers, including Phillips and colleagues, note that higher protein intake (roughly 1.2–1.6 g/kg) during weight loss helps preserve lean muscle mass and supports satiety, making it easier to stick to a calorie deficit.³

Should older people consume more protein compared to younger people?

Yes, this is one of the clearest cases where how much protein do you need per day changes with age. Research reviewed by Phillips and others suggests older adults may need more protein than the RDA to counteract age-related muscle loss (sarcopenia), often in the range of 1.0–1.2 g/kg or higher.³

Is it possible to consume sufficient amounts of protein through plant-based food sources only?

Yes, but it generally takes more planning. Consuming a variety of plant protein foods throughout the day may satisfy your leucine and protein requirements, based on the work done by Layman on protein quality.⁴ 

Key Points

The official RDA of 0.8 g/kg is a legitimate baseline for preventing deficiency, but researchers like Stuart Phillips and Donald Layman, who have each spent decades studying dietary protein, argue it's not necessarily the right answer to how much protein do you need per day if your goal is muscle maintenance, healthy aging, weight management, or athletic performance. For most active adults, something in the 1.2–1.6 g/kg range is a reasonable starting point, with strength-training individuals and older adults often benefiting from the higher end of that range or beyond. Spreading protein evenly across meals, rather than loading it into dinner, appears to matter nearly as much as the total daily number.

Sources & Research Cited

1. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press (2005). nap.edu

2. Layman, D. K. Interview: "Dietary protein: amount needed, ideal timing, quality, and more." The Peter Attia Drive Podcast, Episode #224. peterattiamd.com

3. Phillips, S. M., Chevalier, S., Leidy, H. J. "Protein 'requirements' beyond the RDA: implications for optimizing health." Applied Physiology, Nutrition, and Metabolism, 41(5), 565–572 (2016). PubMed: 26960445

4. Layman, D. K. "Impacts of protein quantity and distribution on body composition." Frontiers in Nutrition, 11:1388986 (2024). PubMed: 38765819