Effects of environmental intervention in workplace cafeterias on vegetable consumption by male workers

Abstract

Objective: To assess the effects of an environmental intervention based on the transtheoretical model to increase access to nutritional information about vegetable consumption in workplace cafeterias.

Design: Nonrandomized controlled trial.

Setting: Sixteen workplaces with cafeterias in Niigata, Japan, were assigned to intervention (n = 8) or comparison sites (n = 8).

Participants: A total of 349 Japanese male workers aged 20-59 years, who visited the cafeterias ≥ 3 times/wk.

Intervention: For the intervention group, 12 types of table tents containing information on increasing vegetable consumption, based on the transtheoretical model stages and processes of change, were distributed to cafeterias for 24 weeks in 2009. Information was presented according to the sequence suggested by the stages of change.

Main outcome measures: Vegetable consumption in the cafeteria and per day and stage of change were assessed using self-administered questionnaires.

Analysis: Differences between groups were tested using a generalized linear model adjusted for age, work environment, and position.

Results: The difference in the stage of change was not statistically significantly different (P = .05), but the intervention group (n = 181) had increased vegetable consumption in the cafeteria (+0.18 servings; P = .01) and per day (+0.32 servings; P = .01) vs the comparison group.

Conclusions and implications: The findings suggest a beneficial effect of providing access to nutrition information about vegetable consumption as an environmental intervention in workplace cafeterias.

Keywords: cafeteria; environmental intervention; transtheoretical model; vegetables; workplace.