An intervention study targeting energy and nutrient intake in worksite cafeterias

Abstract

Modifying the food environment is a promising strategy for promoting healthier eating behavior. This study aimed to evaluate nutritional and weight changes in a program that used worksite cafeterias to reduce employees' calorie content of purchased foods and improve their macronutrient intake. Participants were randomly assigned to one of two conditions: 1) only environmental change (i.e., the introduction of 10 new low-energy-density (ED) foods and provision of labels for all foods sold at lunch, which listed ED, calories, and macronutrient content) or 2) the environmental change plus pricing incentives for purchasing low-ED foods and education about low-ED eating delivered in four, 1-hour group sessions. Participant lunch choices were monitored electronically at the point of purchase for 3 months before the intervention was instituted (i.e., the baseline period) and for 3 months afterward (i.e., intervention period). Participants were adults (n=96, BMI=29.7+/-6.0 kg/m(2)) who regularly ate lunch at their workplace cafeteria. There was no difference between groups in total energy intake over the study period. Across groups, energy and percent of energy from fat decreased and percent of energy from carbohydrate increased from baseline to the intervention period (all p<.01). Follow-up analyses, conducted by averaging Baseline Months 1 and 2 and comparing them to Intervention Month 3 as a conservative estimate of overall impact of the intervention, indicated that change in energy, carbohydrate, and fat intake remained significant (p<.001). Providing nutrition labels and reducing the ED of selected foods was associated with improved dietary intake.

Figure 1

Using cash register data, the energy content of participants’ lunch purchases in the cafeteria was measured. Over the baseline and intervention periods, participants in the Environmental Change (EC; n = 49) and Environmental Change Plus Pricing Incentives and Education (EC-Plus; n = 47) groups were compared. Participants in both groups significantly decreased the overall energy content of their lunch purchases. Baseline Months 1–2 were baseline with no nutrition labels in the cafeteria, and Intervention Months 1–3 included education and labeling.

Figure 2

Using cash register data, the percent of fat in participants’ lunch purchases in the cafeteria was measured. Over the baseline and intervention periods, participants in the Environmental Change (EC; n = 49) and Environmental Change Plus Pricing Incentives and Education (EC-Plus; n = 47) groups were compared. Percent of energy from fat in purchased lunches was significantly higher at Baseline Month 1 than at Intervention Month 3.