How Much Protein Do You Really Need? What Research Actually Says
Should you eat 60 grams of protein a day? 100 grams? 150 grams?
Search online and you will find a different answer on almost every website. Some sources still quote the Recommended Dietary Allowance (RDA) of 0.8 grams per kilogram of body weight, while others claim everyone should consume more than twice that amount.
The reality is simpler: the amount of protein you need depends on your goals, activity level, age and overall health.
The RDA was designed to prevent protein deficiency in sedentary adults, not to maximise muscle growth, recovery or athletic performance.
Here is what the current scientific evidence actually suggests.
Quick Answer
For most healthy adults:
| Goal | Recommended Daily Protein |
|---|---|
| Sedentary adult | 0.8–1.2 g/kg |
| Recreational exercise (2–3 sessions/week) | 1.2–1.6 g/kg |
| Regular strength or hybrid training | 1.6–2.0 g/kg |
| Fat loss while resistance training | 2.0–2.4 g/kg |
These recommendations are starting points and should be adjusted based on your age, training volume, health status and overall goals.
The ranges are based on current evidence from organisations including the International Society of Sports Nutrition (ISSN), the American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics, and Dietitians of Canada.
The baseline everyone quotes
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day.
This figure was established to prevent protein deficiency in the average sedentary adult.
It is a minimum requirement, not necessarily the optimal intake for active individuals.
Think of the RDA as the amount needed to avoid deficiency, not necessarily the amount required to support muscle growth, exercise recovery or healthy ageing.
What sports nutrition research actually says
The International Society of Sports Nutrition recommends 1.4–2.0 g/kg/day for most physically active adults.
Similarly, the American College of Sports Medicine, the Academy of Nutrition and Dietetics, and Dietitians of Canada generally recommend 1.2–2.0 g/kg/day, depending on training demands and recovery goals.
Within these ranges, your training goals influence how much protein you may benefit from.
| Training Goal | Examples | Recommended Protein Intake | Research Notes |
|---|---|---|---|
| Endurance Training | Running, cycling, swimming | 1.2–1.6 g/kg/day | Athletes undertaking very high training volumes may benefit from intakes closer to 1.8 g/kg/day. |
| Strength & Resistance Training | Weight training, CrossFit, HYROX, functional fitness | 1.6–2.2 g/kg/day | This range is associated with supporting muscle growth, recovery and lean mass maintenance in most active individuals. |
| Fat Loss (Calorie Deficit) | Resistance training while losing weight | 2.0–2.4 g/kg/day* | Research suggests 2.3–3.1 g/kg of fat-free mass, which translates to approximately 2.0–2.4 g/kg of body weight for many resistance-trained individuals, helping preserve lean muscle during a calorie deficit. |
Note: Recommendations during fat loss vary depending on body composition, training status and the size of the calorie deficit.
Should you calculate protein using your current body weight?
For most people, yes. If you don't want to do the maths yourself, you can estimate your protein needs using our free CALiberate calculator.
Protein recommendations are generally based on current body weight.
However, for individuals with obesity, healthcare professionals may sometimes use target body weight or lean body mass to avoid substantially overestimating protein requirements.
If you are unsure where to start, calculating using your current body weight is usually the simplest and most practical approach.
Why more protein is not always better
More is not always better.
Current evidence suggests that muscle-building benefits begin to plateau somewhere between approximately 1.6 and 2.2 g/kg/day for most people, depending on factors such as training status, age, energy intake and overall diet quality.
Higher intakes may still be useful during calorie restriction or for certain elite athletes, but this does not mean eating unlimited protein will continue to build more muscle.
The body does not store excess dietary protein for future muscle growth. After repair, recovery and other physiological needs are met, surplus protein is either used for energy or converted into other compounds.
Does meal timing matter?
Total daily protein intake remains the most important factor.
However, research suggests that spreading protein across three to four meals containing approximately 20–40 grams of high-quality protein, or around 0.25–0.40 g/kg per meal, may stimulate muscle protein synthesis more effectively than consuming most of your protein in a single meal.
Rather than chasing a perfect "anabolic window," focus on consistently meeting your daily protein target.
What does this look like in practice?
Example:
- Body weight: 60 kg
- Strength trains 4 times per week
- Recommended daily intake: 96–120 grams of protein
One practical day could look like:
| Meal | Protein |
|---|---|
| Breakfast | 30 g |
| Lunch | 30 g |
| Afternoon snack | 20 g |
| Dinner | 30–40 g |
This approach is often easier to maintain than trying to consume most of your protein in one meal.
Not sure where to start?
If you would like a more personalised estimate based on your body composition, activity level and goals, try CALiberate, Authayn's free metabolism and lifestyle calculator.
It estimates your daily calorie and protein requirements based on your body composition, lifestyle and goals, giving you a practical starting point rather than relying on generic recommendations.
Remember that calculators provide an estimate, not a diagnosis. Your individual needs may vary depending on your health, training intensity and goals.
Scientific Consensus at a Glance
| Organisation | Recommendation |
|---|---|
| International Society of Sports Nutrition (ISSN) | 1.4–2.0 g/kg/day for active individuals |
| American College of Sports Medicine (ACSM) | 1.2–2.0 g/kg/day depending on activity |
| Academy of Nutrition and Dietetics | 1.2–2.0 g/kg/day for athletes |
| Dietitians of Canada | Similar recommendations supporting active populations |
Key Takeaways
- The RDA of 0.8 g/kg/day is the minimum to prevent deficiency, not the optimal intake for active individuals.
- Most people who exercise regularly benefit from 1.2–2.0 g/kg/day.
- Resistance training generally increases protein requirements.
- During fat loss, higher protein intake may help preserve lean muscle.
- Consistency matters more than chasing extremely high protein intakes.
- Meeting your daily target is generally more important than obsessing over exact meal timing.
Protein isn't about eating as much as possible, it is about consistently eating enough to support your goals.