Design and methodology of a continuous national dietary and nutrition survey in France: the Nutrimetry study

Assessing dietary intake and nutritional status requires contemporary data. This paper describes the design of the Nutrimetry survey, a new continuous monitoring system in France, its participation rate, and the quality of its dietary data.

A representative sample of adults (18-79 years) and children (3-17 years) was selected using a non-probability quota sampling design. Quotas included age, sex, region, urban unit size, and socio-professional category, weighted against 2021 census data.

Food consumption was collected via a 3-day online dietary record. Information on physical activity, sedentary behaviour, and sociodemographic was gathered by questionnaires. Complex foods were disaggregated into raw ingredients using a standardized recipe optimization process.

In total, 3,201 individuals (2,193 adults and 1,008 children) were included in 2024 results.

The final sample represented 7% of adult starters and 45.2% of eligible children. Mean energy intake was 1,852 kcal/d in adults and 1,693 kcal/d in children. The prevalence of energy under-reporting was 33.8% for adults and 22.6% for children. Under-reporting was significantly associated with higher BMI and younger age groups.

The Nutrimetry survey provides a robust, scalable framework for continuous national dietary surveillance in France. Despite challenges with online recruitment attrition, it generates timely data for public health policy and nutritional risk assessment.