Improving the diet of employees at blue-collar worksites: results from the 'Food at Work' intervention study.

OBJECTIVE To examine the impact of a 6-month participatory and empowerment-based intervention study on employees' dietary habits and on changes in the canteen nutrition environment. DESIGN Worksites were stratified by company type and by the presence or absence of an in-house canteen, and randomly allocated to either an intervention group (five worksites) or a minimum intervention control group (three worksites). The study was carried out in partnership with a trade union and guided by an ecological framework targeting both individual and environment levels. Outcome measures included: (i) changes in employees' dietary habits derived from 4 d pre-coded food diaries of a group of employees at the worksites (paired-data structure); and (ii) the canteen nutrition environment as identified by aggregating chemical nutritional analysis of individual canteen lunches (different participants at baseline and at endpoint). SETTING Eight blue-collar worksites (five of these with canteens). SUBJECTS Employees. RESULTS In the intervention group (n 102), several significant positive nutritional effects were observed among employees, including a median daily decrease in intake of fat (-2.2 %E, P = 0.002) and cake and sweets (-18 g/10 MJ, P = 0.002) and a median increase in intake of dietary fibre (3 g/10 MJ, P < 0.001) and fruit (55 g/d, P = 0.007 and 74 g/10 MJ, P = 0.009). With regard to the canteen nutrition environment, a significant reduction in the percentage of energy obtained from fat was found in the intervention group (median difference 11 %E, P < 0.001, n 144). CONCLUSIONS The present study shows that moderate positive changes in dietary patterns can be achieved among employees in blue-collar worksites.