Predicting achievement of a low-fat diet: A nutrition intervention for adults with low literacy skills

Abstract

Background. This paper identifies factors that predict achievement of a low-fat diet among 242 California adults with low literacy skills, following their participation in the Stanford Nutrition Action Program (SNAP), a randomized classroom-based nutrition intervention trial (1993-1994). Methods. The intervention classes received a newly developed curriculum that focuses on reducing dietary fat intake (SNAP); the control classes received an existing general nutrition (GN) curriculum. Data were collected at baseline and 3 months postintervention. This hypothesis-generating analysis uses a signal detection method to identify mutually exclusive groups that met the goal of a low-fat diet, defined as <30% of calories from total fat, at 3 months postintervention. Results. Three mutually exclusive groups were identified. Twenty-three percent of Group 1, participants with high baseline dietary fat (>60 g) who received either the GN or the SNAP curriculum, met the postintervention goal of <30% of calories from total fat. Thirty-four percent of Group 2, participants with moderate baseline dietary fat (≤ 60 g) who received the GN curriculum, were successful. Sixty percent of Group 3, participants with moderate baseline dietary fat who received the SNAP curriculum, were successful. Members of Group 3 also significantly increased their intake of vegetables, grains, and fiber. Conclusions. Within this population of adults with low literacy skills, a large proportion of those with moderate baseline dietary fat who participated in the SNAP classes met the postintervention criteria for a low-fat diet. A much smaller proportion of those with high baseline dietary fat were successful, suggesting that this group may benefit from different, more intensive, or longer-term interventions.