Internal locus of control and social support associated with some dietary changes by elderly participants in a diet intervention trial

Objective Measure relationships of locus of control and social support to d iet changes in an intervention trial. Design Participants in the Polyp Prevention Trial (PPT) completed Multidime nsional Health Locus of Control (MHLC) and Norbeck Social Support Questionn aires (NSSQ) and modified Block food frequency questionnaires. Data were co llected at baseline and 1 year later. Subjects/setting A convenience sample of PPT intervention (N = 68) and cont rol (n = 43) participants at 1 clinical center participated in this ancilla ry study. Main outcome measures Mean daily dietary intakes after 1 year were compared with baseline values. Intervention participants' scores for MHLC internal locus of control and NSSQ total functional network were correlated with die t changes. Statistical analyses performed Group percentages were compared using the Fi sher exact test; means were compared by t test. Results Groups were comparable in demographics, baseline diet, and scores f or internal locus of control and total functional network. Intervention gro up participants made greater diet changes than control participants in inta ke of fat (-27 g vs -8 g), fat as a percentage of kilocalories (-8% vs -2%) , fiber as grams per 1,000 kcal (7 g vs 0.3 g), and daily fruit/vegetable s ervings (2.0 vs 0.2). Pearson correlations of diet changes with internal lo cus of control scores (all P > .05) were fat grams, r = 0.031; fat as perce ntage of kilocalories, r = 0.023 fiber grams per 1,000 kcal; r = 0.230; and fruit/vegetable servings, r = 0.186. Correlations with total functional ne twork scores were: fat grams, r = 0.022 (P > .05); fat as percentage of kil ocalories, r = -0.108 (P > .05); fiber grams per 1,000 kcal, r = 0.276, P < .05; and daily fruit/vegetable servings, r = 0.326, P < .05. Applications/Conclusions Intensive and skillful dietary intervention can su cceed whether or not clients bring strong internal locus of control or soci al support to the diet change program.