To evaluate the effectiveness of PASOS SALUDABLES, a culturally tailored lifestyle intervention to prevent obesity and diabetes among Latino farmworkers, when implemented at large scale in the worksite.

This study was a two-arm parallel group, cluster randomised controlled trial, where participants received either a twelve-session lifestyle intervention (intervention) or six-session leadership training (control) at their worksite. The intervention was delivered by Promotoras in Spanish. All sessions were conducted at the worksites (ranches) during meal breaks. Blinded, trained research assistants collected socio-demographic and outcome data (i.e. BMI as primary outcome and waist circumference, glycated Hb (HbA1c), cholesterol and blood pressure as secondary outcomes) at baseline and follow-up assessments (i.e. 3 months, 6 months, 1 year and 1·5 years).

Recruitment and intervention delivery occurred at twelve study ranches in Oxnard, California.

We enrolled farmworkers hired by a large berry grower company, who were ≥18 years old, spoke Spanish and were free of diabetes at screening.

A total of 344 workers were enrolled in the intervention and 271 in the control group. The intervention resulted in attenuated increase of BMI over time; however, the difference in trend between groups was not significant (β = −0·01 for slope difference, P = 0·29). No significantly different trend by group was observed in secondary outcomes (P > 0·27).

The worksite intervention, implemented during meal breaks, did not reduce BMI or other clinical indicators. Nevertheless, this study supports the feasibility of recruiting and engaging the Latino farmworker population in workplace health promotion interventions.