High Prevalence of Low Creatine Intake among Individuals Following Common Special Diets.

INTRODUCTION: Creatine is a conditionally essential nutrient central to cellular energy metabolism, with roughly half of daily requirements derived from dietary sources found exclusively in animal-based foods. Insufficient dietary creatine intake has been linked to various adverse health outcomes, yet data on creatine adequacy among individuals following special diets remain limited. This study examined the prevalence of low dietary creatine intake among US individuals adhering to different special diets using cumulative data from the National Health and Nutrition Examination Survey (NHANES). METHODS: Data from NHANES 2003-2023 cycles were merged to identify participants (≥1 year old) reporting adherence to a special diet in the Dietary Data domain. Self-reported diets were categorized into thirteen groups (e.g., weight-loss, diabetic, low-fat, low-carbohydrate, gluten-free). Dietary creatine intake, estimated using established methods and excluding supplements, was classified as adequate (≥1 g/day) or inadequate (<1 g/day). Differences in the prevalence of inadequate creatine intake across diet types were assessed using chi-square tests with Bonferroni-adjusted post hoc comparisons. RESULTS: Among 8,407 participants (57.8% female; mean age = 45.0 ± 21.5 years) reporting adherence to a single special diet, mean creatine intake was 0.82 ± 0.82 g/day, with 69.5% classified as having inadequate intake. The prevalence of low creatine intake differed significantly across diet types (p < 0.0001), ranging from 83.3% in low-fiber diets to 60.4% in renal diets. Individuals following low-carbohydrate diets exhibited a significantly lower prevalence of inadequate intake (p = 0.00097), while high- and low-fiber, gluten-free, and weight-loss diets were associated with higher prevalence rates. Women showed greater creatine insufficiency than men across several dietary categories. CONCLUSION: Inadequate dietary creatine intake is highly prevalent among individuals following a variety of special diets in the US population. Restrictive or plant-forward regimens appear particularly associated with insufficient intake, underscoring the need for nutritional strategies - such as creatine-fortified foods or supplementation - to maintain optimal creatine homeostasis and support metabolic health in at-risk groups.