The Claim

In older women aged 66 years with a BMI of 28, consuming 1.4 grams of protein per kilogram of body weight daily from lean beef or mixed sources for 12 weeks while performing supervised resistance training three times per week does not significantly enhance increases in quadriceps muscle volume or strength beyond those achieved with resistance training alone, regardless of whether protein intake is at the recommended 0.8 g/kg/d or higher.

Source: 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

What the research says

Supports is higher

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

Supports
69score
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.

Cause and effect
1 study reviewed
In plain English

For women aged 66 with a BMI of 28, increasing protein intake to 1.4 g/kg/day from lean beef or mixed sources while doing supervised resistance training three times per week for 12 weeks does not result in greater increases in quadriceps muscle volume or strength compared to resistance training alone with 0.8 g/kg/day protein intake.

See the scientific wording

In older women aged 66 years with a BMI of 28, consuming 1.4 grams of protein per kilogram of body weight daily from lean beef or mixed sources for 12 weeks, while performing supervised resistance training three times per week, does not significantly enhance increases in quadriceps muscle volume or strength beyond those achieved with resistance training alone, regardless of whether protein intake is at the recommended 0.8 g/kg/d or higher.

Why this might work

When older women perform resistance training, their muscles and tendons respond to the physical stress by building more muscle tissue and thickening tendons. Eating more protein, even from sources rich in leucine, glycine, or proline, does not make this process any stronger or faster. The body already uses the protein it needs from the standard intake to support these changes, and extra protein does not trigger more muscle growth or strength gain.

Verified mechanismbased on 1 study

What the research says

1 study
  1. 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

    For older women who lift weights, eating more protein from beef or other sources doesn't make their muscles bigger or stronger than eating the normal amount — the workouts did all the work, no matter how much protein they ate.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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