The Claim

A severe negative energy balance of approximately 70% (−1849 ± 511 kcal/d) sustained for 21 days at an altitude of 4300 meters causes a loss of 3.6 ± 2.4 kg of fat-free mass in healthy adult males aged 23 ± 6 years, regardless of whether dietary protein intake is standardized at 1.0 g/kg or increased to 2.0 g/kg per day.

Source: Severe negative energy balance during 21 d at high altitude decreases fat‐free mass regardless of dietary protein intake: a randomized controlled trial

What the research says

Supports is higher

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

Supports
46score
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

When healthy adult men at high altitude consume significantly fewer calories than they burn for three weeks, they lose about 3.6 kilograms of lean body mass, whether they eat 1.0 or 2.0 grams of protein per kilogram of body weight daily.

See the scientific wording

Severe negative energy balance of approximately 70% (−1849 ± 511 kcal/d) sustained for 21 days at an altitude of 4300 meters causes a loss of 3.6 ± 2.4 kg of fat-free mass in healthy adult males aged 23 ± 6 years, regardless of whether dietary protein intake is standardized at 1.0 g/kg or increased to 2.0 g/kg per day.

What the research says

1 study
  1. Study: Severe negative energy balance during 21 d at high altitude decreases fat‐free mass regardless of dietary protein intake: a randomized controlled trial

    Even if men ate twice as much protein while at high altitude and eating far fewer calories, they still lost the same amount of muscle — meaning more protein didn’t help protect their muscles in this extreme situation.

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

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