The Claim

In healthy obese adults, a low-carbohydrate high-protein diet for 24 months increases urinary calcium excretion by up to 36.1% at 3 months and 35.7% at 12 months compared to a low-fat diet, without detectable changes in bone mineral density or clinical kidney stone events.

Source: Comparative effects of low-carbohydrate high-protein versus low-fat diets on the kidney.

What the research says

Supports is higher

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

Supports
74score
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

In healthy obese adults, switching to a low-carbohydrate, high-protein diet for up to 24 months increases calcium loss in urine by about 36% at 3 and 12 months compared to a low-fat diet, but does not change bone density or cause kidney stones.

See the scientific wording

In healthy obese adults, a low-carbohydrate high-protein diet for 24 months increases urinary calcium excretion by up to 36.1% at 3 months and 35.7% at 12 months compared to a low-fat diet, without detectable changes in bone mineral density or clinical kidney stone events, indicating that increased calcium excretion does not necessarily lead to bone or stone pathology in this population.

Why this might work

Eating more protein causes the kidneys to filter more blood and produce more acid, which makes the urine more acidic. This reduces the ability of the kidneys to reabsorb calcium, so more calcium leaves the body in urine. The increased blood flow through the kidneys also pushes more calcium out, but the bones and kidneys do not get damaged because the body adjusts to this change.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Comparative effects of low-carbohydrate high-protein versus low-fat diets on the kidney.

    People on a low-carb, high-protein diet pee out more calcium than those on a low-fat diet, but their bones don’t get weaker and they don’t get more kidney stones — so the extra calcium in urine isn’t harmful in this group.

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

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