RESUMO
BACKGROUND: Capacity-building of health professionals regarding to nutrition is a strategy for qualifying public health work to promote healthy diets in primary health care (PHC) services. OBJECTIVE: To evaluate the effect of an intervention based on Brazilian Dietary Guidelines (BDG) on the knowledge, self-efficacy (SE) and collective efficacy (CE) of interprofessional teams working in PHC. METHODS: It refers to a pre-post intervention study involving 24 health professionals divided into a control group (CG) and intervention (IG). The IG received a 16-h educational workshop on the BDG, guided by a validated protocol. Knowledge, SE and CE for using the BDG were assessed via a self-administered scale, ranging from 0 to 16 and 0 to 36 points, respectively; the scale was previously validated, completed before and after 2 months of the intervention. The effects of the intervention were estimated by paired t-test for intragroup comparisons over time. RESULTS: The mean difference in the knowledge and SE scores of the IG pre- and post-intervention was 2.0 (CI 0.49-3.51) and 6.75 (CI 4.05-9.45) points, respectively. These results means the IG participants obtained 59 and 52.8% more points in knowledge and in SE in relation to CG, with significative difference (p = 0.007 and p < 0.00, respectively). There was no significant variation in the CE scores in both groups. CONCLUSIONS: Considering the results presented and due to the originality of the study in question, the educational workshop was effective in increasing the knowledge and SE of professionals working in PHC in using the Dietary Guidelines in their work routines. These findings can assist other research in developing nutrition interventions with interprofessional teams.