Diet, lifestyle factors and human fertility: what we know, what we wish we knew, and what we may never know

The authors investigate the impact of diet, lifestyle factors, and substance use on human fertility, amidst growing concerns about declining birth rates and semen quality. They aim to identify actionable recommendations based on current evidence while acknowledging the gaps in knowledge and the limitations of available data. The review categorizes questions into those that can be robustly answered, those that are still open but addressable, and those that may remain unresolved, emphasizing the need for balanced guidance in reproductive health.