Nutrition interventions in the first 1000 days and long-term health outcomes: a systematic review

Nutrition in early life can influence health in later life. This systematic review evaluated the impact of nutrition intervention programs in the first 1000 days of life on long-term cardio-metabolic, respiratory, and mental health and dietary behaviour in children.

Randomized controlled trials (RCTs) from high-income countries were searched in four databases and two trial registries in March 2020, and updated in November 2022. Risk of bias was evaluated using the Cochrane Risk of Bias tool and certainty of results using the GRADE considerations. Results were synthesized narratively.

Sixty-three articles covering 20 interventions were included. Most interventions began in early infancy (<6 months of age), lasted 12-36 months and had follow-ups under five years. Initial results showed some positive impact of interventions on cardio-metabolic health (three RCTs). No effect was found on mental health (four RCTs), while no RCT reported on respiratory health. Interventions showed some improvements on dietary behaviour, with mixed results across studies.

Trials on early nutritional interventions seldom report health outcomes with long-term follow-ups. There is some evidence of a positive impact on cardio-metabolic health and dietary behaviour.

In the assessed studies, nutritional interventions in the first 1000 days of life mainly had short follow-ups and reported heterogeneous outcomes. There was some evidence that nutritional interventions can improve children's dietary behaviour and cardio-metabolic health, while there was no effect on mental health. We provide a systematic review on the impact of early nutrition intervention programs on long-term health outcomes in children showing research gaps for intervention studies with long-term and clinically relevant outcomes. Understanding the effectiveness and implementation of early nutritional interventions provides insights for preventative population health and affects future intervention planning.