The Claim

The optimal protein intake for healthy adults is 1.2 to 1.6 grams per kilogram of body weight, and for individuals engaged in resistance training, protein intake up to 1 gram per pound of body weight is recommended.

Source: Fact Checking The Latest Anti-Protein Myth

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
90score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Description
8 studies reviewed
In plain English

Healthy adults should consume 1.2 to 1.6 grams of protein per kilogram of body weight. People who do resistance training should aim for up to 1 gram of protein per pound of body weight.

See the scientific wording

Optimal protein intake for healthy adults is 1.2 to 1.6 grams per kilogram of body weight, with higher intakes (up to 1 gram per pound) recommended for individuals engaged in resistance training.

Why this might work

When a person eats enough protein, especially after exercise, the amino acid leucine rises in the blood and turns on a key switch in muscle cells called mTORC1. This switch tells the muscle to build more protein and stop breaking it down, leading to stronger and larger muscles over time. Higher protein intake also lowers inflammation, which removes another barrier to muscle growth.

Verified mechanismbased on 8 studies

What the research says

8 studies

  1. Study: Effect of a protein intervention during resistance training with varying training intensities on muscle outcomes in frail community-dwelling older adults: a randomized controlled trial

    The study found that older adults who didn’t eat enough protein got much stronger when they started eating more — about 1.2 grams per kilogram of body weight — which matches the recommended amount in the claim. It didn’t help people who already ate enough, but that doesn’t mean the recommendation is wrong.

  2. Study: Correlation between physiological and biochemical variables during short term adequate protein intake combined with resistance exercise in sedentary adults

    This study found that eating 1.5 grams of protein per kilogram of body weight (which is within the recommended range) while doing strength training helped people build more muscle and get stronger. So yes, the recommended protein amount works.

  3. Study: Greater Protein Intake Emphasizing Lean Beef Does Not Affect Resistance Training-Induced Adaptations in Skeletal Muscle and Tendon of Older Women: A Randomized Controlled Feeding Trial

    People who lift weights may not get bigger muscles from eating more protein, but their tendons stay healthier. This study shows that eating the amount of protein recommended (1.4 g/kg) helps protect tendons from shrinking, which supports the idea that higher protein is useful for active people.

  4. Study: Similar effects between animal-based and plant-based protein blend as complementary dietary protein on muscle adaptations to resistance training: findings from a randomized clinical trial

    This study showed that young men who drank protein shakes (about 45 grams a day) while lifting weights gained more muscle and strength — whether the protein came from plants or animals. This supports the idea that people who lift weights should eat more protein, as the claim suggests.

Related videos

Fact Checking The Latest Anti-Protein Myth

Shawn Baker MD

Fact Checking The Latest Anti-Protein Myth

Read analysis

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 8 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.