Effects of an elimination diet and a healthy diet in children with Attention‐Deficit/Hyperactivity Disorder: 1‐Year prospective follow‐up of a two‐arm randomized, controlled study (TRACE study)

An Elimination Diet (ED) or Healthy Diet (HD) may be effective in reducing symptoms of Attention‐Deficit/Hyperactivity Disorder (ADHD), but long‐term maintenance effects and feasibility have never been examined.One‐year prospective follow‐up of a sample of 165 children (5–12 years) with ADHD randomized (unblinded; 1:1) to 5 weeks treatment with either ED (N = 84) or HD (N = 81) and a non‐randomized comparator arm including 58 children being treated with Care as Usual (CAU). Dietary participants were allowed to add or switch to CAU treatment after 5 weeks. The primary outcome was a 5‐point ordinal measure of improvement based on both parent and teacher ratings on ADHD and dysregulation problems, determined after 1 year prospective follow‐up. Ordinal regression analyses and linear mixed models analyses were conducted on an intention to treat basis. In addition, as‐treated analyses were performed. The trial is closed and registered in the Dutch trial registry, number NL5324.At 1 year follow‐up, 24% of the participants still complied with the ED and 37% still complied with the HD. In the ED (+CAU) trajectory, fewer participants showed (partial) improvement after 1‐year prospective follow‐up compared to the HD (+CAU) trajectory (47% vs. 64%, χ2 (4, N = 152) = 11.97, p = 0.018). The HD (+CAU) ‐ but not ED (+CAU) ‐ trajectory had comparable 1‐year outcomes compared to the non‐randomized CAU‐trajectory. Results for secondary outcomes (e.g. health, parental stress) did not differ between the ED (+CAU) and HD (+CAU) trajectories. The prevalence of psychostimulant use was lower in the ED (+CAU) and HD (+CAU) trajectories compared to the non‐randomized CAU‐trajectory (38%, 45%, 78%, respectively). Predictors for long‐term benefit from dietary treatments included high initial severity of ADHD problems, low severity of emotional problems and sufficient parental mental resources.In line with the short‐term effects, prospective 1‐year follow‐up outcomes are in favor of treatment with HD and not ED. Initial 5‐week treatment with HD and if needed/preferred followed by CAU may reduce psychostimulant use without negatively impacting 1‐year outcomes.