To evaluate the feasibility of diet mediterranisation, in a food-at-work context, and its consequence on metabolic syndrome in a mid-age unselected healthy male population group.

One-year longitudinal intervention study. Physical exercise was not modified.

All workers of the Santiago division of ‘Maestranza Diesel’, a metal-mechanic company servicing the mining industry, were invited to participate.

Initially, 145 workers of a total of 171, of average age 39 years, accepted to participate (sixteen women and 129 men). A subgroup of ninety-six men fully completed the controls programmed for the intervention study. Losses from the original group correspond to missing one control (sixteen), leaving the company (eleven) or blood sampling discomfort (six). The women and sixteen male workers, hired post study initiation, did participate but were excluded from this 12-month analysis.

Diet mediterranisation was successful, reflected in the daily food consumption at the canteen and the evolution of the Mediterranean diet score (MDS) from 4·8 ± 1·4 to 7·4 ± 1·5 (limits 0–14). Some metabolic syndrome components showed statistically significant improvement and also statistically significant correlation with the MDS: waist circumference, HDL-cholesterol, systolic and diastolic blood pressure. After 12 months, the reversion rate for metabolic syndrome was 48 % (12/23) with an incidence rate of 4·1 % for new cases (3/73). In total, metabolic syndrome decreased from 24·0 % to 15·6 % (23/96 to 15/96) (P = 0·029).

Diet mediterranisation is feasible in a food-at-work intervention, affecting lunch consumption at the workers canteen and overall consumption evaluated with MDS, together with a significant reduction in metabolic syndrome.