This large, prospective, cohort study found that consumption of red meat and poultry increased risk of kidney stones, while fresh fruit decreased risk.
In conclusion, compared to meat-eaters, vegetarians are at a lower risk of being hospitalised for kidney stones. Among meat-eaters, increasing meat intake is associated with a higher risk of developing kidney stones. Conversely, a high intake of fresh fruit, fibre and magnesium may reduce the risk.
There were no associations between dietary intake of sodium or calcium and kidney stone risk.
It has been proposed that metabolism of a high protein diet may result in an increased stone risk by producing an acid load that increases urinary calcium and oxalate levels and decreases levels of citrate (an inhibitor of calcium stone formation).