Dietary Intake of Overweight and Obese Men Diagnosed with Prostate Cancer Before and After a Lifestyle Intervention

Thesis (Master's)--University of Washington, 2018Background: There is increasing evidence that obesity is correlated with prostate cancer (PC) progression and PC-related mortality among men on active surveillance (AS). Interventions aimed at weight loss among obese men on AS are not a current part of standard care. The Prostate Cancer Active Lifestyle Study (PALS) is an ongoing randomized control trail (RCT) where researchers are investigating the effects of a lifestyle intervention on biomarkers of glucose regulation and disease progression among overweight and obese men on AS. The PALS RCT provides an opportunity for researchers to examine dietary patterns of men before and after a lifestyle intervention. Objectives: The purpose of this study was to describe dietary intake of food groups targeted in the PALS intervention materials -fruits, vegetables, sweetened beverages, alcohol, added fats, sweets and desserts, and sweets as condiments- among PALS participants at baseline and to determine whether intake of these seven categories significantly differed between and within two study arms, the intervention arm and control arm, from baseline to 6-months. Hypothesis 1: Among the intervention arm, average daily intake of fruit and vegetable servings would be significantly higher and average daily intakes of sweetened beverages, alcohol, added fats, sweets and desserts, and sweets as condiments would be significantly lower compared to the control arm. Hypothesis 2: At six-months, average daily intake of fruit and vegetables would be significantly higher and average daily intakes of sweetened beverages, alcohol, added fats, sweets and desserts, and sweets as condiments would be significantly lower among the intervention arm. Methods: PALS participants (n=23) were randomized to control or intervention. Participants in the control arm (n=11) were provided standard nutrition and exercise information through one, 30-minute session. Participants in the intervention arm (n=12) took part in a 6-month lifestyle intervention based on the Diabetes Prevention Program. Using 3-day food records collected at baseline and 6-months, dietary intake of the seven food categories was determined. Chi-squared and two-sample t-tests were used to assess demographic differences among participants at baseline. Two-sample t-tests were used to detect differences in intake between study arms and paired t-tests were used to detect differences within study arms. Two-samples t-tests were used to compare changes in mean intake between the study arms from baseline to follow-up. Results: There were no significant differences in intake at baseline nor at 6-months between the two study arms. There were no significant differences in intake between baseline and 6-months among controls. There was a borderline decrease in sweets and desserts from baseline to 6-months among participants in the intervention arm (1.17±1.38 servings/d to 0.43±0.68 servings/d, P=0.05). Conclusions: A lifestyle intervention may be a factor in the decreased intake of sweets and desserts among overweight and obese men on AS. Larger studies are needed to determine whether this intervention will illicit substantial changes in average daily intake of fruits, vegetables, sweetened beverages, alcohol, added fats, sweets and desserts, and sweets as condiments