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 diet changes in an intervention trial.


METHODS
Participants in the Polyp Prevention Trial (PPT) completed Multidimensional Health Locus of Control (MHLC) and Norbeck Social Support Questionnaires (NSSQ) and modified Block food frequency questionnaires. Data were collected at baseline and 1 year later.


METHODS
A convenience sample of PPT intervention (N = 68) and control (n = 43) participants at 1 clinical center participated in this ancillary study.


METHODS
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 diet changes.


METHODS
Group percentages were compared using the Fisher exact test; means were compared by t test.


RESULTS
Groups were comparable in demographics, baseline diet, and scores for internal locus of control and total functional network. Intervention group participants made greater diet changes than control participants in intake 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 servings (2.0 vs 0.2). Pearson correlations of diet changes with internal locus of control scores (all P > .05) were fat grams, r = 0.031; fat as percentage 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 network scores were: fat grams, r = 0.022 (P > .05); fat as percentage of kilocalories, 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.


CONCLUSIONS
Intensive and skillful dietary intervention can succeed whether or not clients bring strong internal locus of control or social support to the diet change program.
Polyp Prevention Trial Clinical Center, Edward Hines Jr. Veterans Affairs Hospital, Fifth Ave. & Roosevelt Rd., PO Box 5000, 151V, Hines, IL 60141, USA. murphy@research.hines.med.va.gov
P A
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Murphy
T E
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Prewitt
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Boté
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West
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Iber
D000368:Aged; D004041:Dietary Fats; D004043:Dietary Fiber; D004435:Eating; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D005638:Fruit; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion; D006801:Humans; D007389:Internal-External Control; D008297:Male; D009042:Motivation; D012931:Social Environment; D012944:Social Support; D011795:Surveys and Questionnaires; D014675:Vegetables
D004041:Dietary Fats; D004043:Dietary Fiber