Kidney stone disease is increasingly common in the general population; recent estimates suggest a prevalence higher than 10% in the United States.1 To reduce the burden and associated high costs for health systems,2 a large body of literature has focused on modifiable risk factors, especially dietary, thought to play a role in the pathogenesis of the disease.3 However, given the time and large expense required to perform a randomized controlled trial, most of the available evidence on the benefit or harm of certain dietary factors derives from observational studies, which—depending on the study design—could be potentially subject to issues such as reverse causation or residual confounding.