Considering Patient Diet Preference to Optimize Weight Loss
William S. Yancy MD MHS
Durham VA Medical Center, Durham, NC
Durham, NC
Funding Period: October 2010 - September 2013

BACKGROUND/RATIONALE:
The prevalence of obesity (body mass index [BMI] 30 kg/m2) in US adults has skyrocketed over the past 30 years, affecting approximately 33% in the VA nationally in 2000 and approximately 36% at the Durham VAMC currently. Thus, identifying effective strategies for treating obesity is both a public health and a VA priority. A variety of diet approaches have proven successful in achieving moderate weight loss in many individuals. Most diet interventions fail to achieve meaningful weight loss in more than a few individuals. This failure likely results from inadequate adherence to the diet.

OBJECTIVE(S):
The proposed study will test the commonly proposed assumption that helping patients to choose a diet based on their dietary preferences will increase weight loss success relative to assigning or recommending a single diet. The objectives of this study are to: (a) examine the difference in weight loss at 48 weeks among participants randomized to the Choice arm versus participants randomized to the Control arm; (b) examine the difference in diet adherence at 48 weeks among participants randomized to the Choice arm versus participants randomized to the Control arm; and (c) examine the difference in obesity-specific health-related quality of life (HRQOL) at 48 weeks among participants randomized to the Choice arm versus participants randomized to the Control arm.

METHODS:
The proposed study is a 2-arm randomized controlled trial involving 216 outpatients from Durham VA Medical Center. Participants must be obese (BMI 30 kg/m) VAMC outpatients without unstable health issues. Participants in the experimental arm (Choice) will select either a low-carbohydrate, calorie-unrestricted diet (LCD) or a low-fat, reduced-calorie diet (LFD) after being informed by results from a validated food preference questionnaire and a discussion of available diet options with trained personnel. The Choice participants will also have the opportunity to switch to the other diet after 3 months if unsuccessful or dissatisfied with their primary selection. Participants in the Control arm will be randomly assigned to follow one of the two diets for the duration of follow-up. All participants will receive diet-appropriate counseling in small group meetings every 2 weeks for 24 weeks, then monthly for another 24 weeks. All participants will also receive brief telephone counseling involving individual goal setting and problem solving halfway through each month in the latter 24 weeks.

The primary outcome is weight change from baseline to 48 weeks. Secondary outcomes include adherence to diet by food frequency questionnaire and obesity-specific health-related quality of life. Exploratory analyses will examine whether the impact of choice versus lack of choice on weight loss is moderated by individual differences in the constructs of autonomy orientation, competence, and relatedness.

FINDINGS/RESULTS:
Data collection is still in progress. No findings to date.

IMPACT:
If assisting patients to choose their diet enhances adherence and increases weight loss, the results from this study will support the provision of diet options to veterans and non-veterans alike, and bring us one step closer to remediating the obesity epidemic faced by the VA and other healthcare systems.

PUBLICATIONS:

Journal Other

1. Yancy WS. Peer Support Significantly Improves Compliance in Veterans with Diabetes. U. S. Medicine. 2012 Nov 20.

DRA: Other Conditions
DRE: Treatment - Comparative Effectiveness
Keywords: Patient Preferences
MeSH Terms: none