The Claim

In older women performing resistance training, a protein intake of 1.4 g/kg/d increases blood urea nitrogen levels compared to a protein intake of 0.8 g/kg/d, with no evidence of adverse effects.

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
34score
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

Older women who do resistance training and consume 1.4 grams of protein per kilogram of body weight per day have higher blood urea nitrogen levels than those who consume 0.8 grams per kilogram per day, without signs of harm.

See the scientific wording

In older women performing resistance training, higher protein intake (1.4 g/kg/d) increases blood urea nitrogen levels compared to the recommended intake (0.8 g/kg/d), indicating greater protein metabolism without evidence of adverse effects.

Why this might work

When more protein is eaten, the body breaks down the extra amino acids in the liver, removes their nitrogen groups, and turns them into urea, which shows up as higher levels in the blood. This process happens without damaging the muscles or tendons, even in older women who lift weights.

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

    When older women ate more protein, their bodies broke it down more — which usually means more urea in the blood — and this didn’t hurt their muscles or tendons. So yes, more protein means more processing, but it’s not harmful.

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

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