Standardisation of diet and exercise in clinical trials of NAFLD-NASH: Recommendations from the Liver Forum.

Lifestyle modification is the foundation of treatment recommendations for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The design of clinical trials in NASH may be impeded by the lack of a systematic approach to identify and evaluate how lifestyle changes and/or modifications influence clinical trial outcomes and associated endpoints. Furthermore, there are additional uncertainties regarding the methods that can be utilised to better characterise and quantify lifestyle variables - which can influence disease activity and alter trial endpoints - to allow for comparisons of trial outcomes across different phases of research and/or within drug-classes. This summary by the Liver Forum's Standard of Care Working Group reviews currently available clinical data, identifies the barriers and challenges associated with the standard of care in NAFLD/NASH clinical trials, defines available assessments of lifestyle changes, and proposes approaches to better understand and define the influence of diet and exercise on NASH treatment in the context of different pharmacologic interventions. The ultimate objective is to propose tangible solutions which enable investigators, sponsors, and regulatory authorities to meaningfully interpret clinical trial outcomes and the impact of lifestyle modification on such outcomes as they pertain to phase I-IV clinical trials.