Study protocol on the safety and feasibility of a normocaloric ketogenic diet in people with amyotrophic lateral sclerosis.

Objectives: This study evaluates the safety and feasibility of a normocaloric ketogenic diet (KD) in people with amyotrophic lateral sclerosis (ALS) for reducing hyperexcitability levels and modulating neuroinflammation.

Methods: This is a prospective, open-label pilot study involving men and women diagnosed with ALS, ages 18 to 75 y. The primary outcome is the safety and reproducibility of the KD in people with ALS. We will monitor secondary clinical outcomes with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale score, forced vital capacity, the Amyotrophic Lateral Sclerosis Assessment Questionnaire, blood parameters, and gut microbiota analyses. All participants will follow the KD for 8 wk. During the diet, the clinical status of all participants will be monitored every 15 d through neurologic and nutritional visits and biochemical markers. The research ethics committee approved the study.

Results: Safety will be assessed by measuring the number and severity of adverse events, including death, and any changes in blood chemistry, vital signs, and clinical exam results. Tolerability will be assessed to complete the proposed 8 wk of treatment while maintaining adequate nutritional status without inducing malnutrition.

Conclusions: Adequate caloric intake is essential in ALS, because insufficient intake induces loss of body mass. We hope that the proposed study will provide a positive result in terms of the safety and feasibility of a KD in people ALS, with the purpose of developing a patient-centered diet program to limit disease progression and possibly improve survival.