(P20-027-20) Does Personalized Nutrition Increase Weight Loss Self-Efficacy?

Objectives: We examined whether a diet personalized to reduce postprandial glycemic response (PPGR) to foods increases weight loss self-efficacy.

Methods: The Personal Diet Study is an ongoing clinical trial that aims to compare two weight loss diets: a one-size-fits-all, calorie-restricted, low-fat diet (Standardized) versus a diet having the same calorie restriction but utilizing a machine learning algorithm to predict and reduce PPGR (Personalized).  Both groups receive the same behavioral counseling to enhance weight loss self-efficacy.  Both groups self-monitor dietary intake using a mobile app, with Standardized receiving real-time feedback on calories and macronutrient distribution, and Personalized receiving real time feedback on calories, macronutrient distribution, and predicted PPGR. We examined changes in self-efficacy between baseline and 3 mos, using the 20-item Weight Efficacy Lifestyle questionnaire (WEL). Linear mixed models were used to analyze differences, adjusting for age, gender, and race.

Results: The analyses included the first 75 participants to complete 3-mos assessments (41 Personalized and 34 Standardized). The majority of the participants were white (69.3%), female (61.3%), with a mean age of 61.7 years (SD=9.9) and BMI of 33.4 kg/m2 (SD=4.8). At baseline, WEL scores were similar between the 2 groups [Standardized WEL: 118.8 (SD=27.6); Personalized WEL: 124.9 (SD=29.5), p=.47]. At 3 mos, the WEL score was significantly improved in both groups [16.0 (SD=4.1) in the Standardized group (p< .001) and 7.4 (SD=3.7) in the Personalized group (p=.048)], but the between group difference was not significant (p= .12).

Conclusions: Personalized feedback on predicted PPGRs does not appear to enhance weight loss self-efficacy at 3 mos. The lack of significance may be related to the short follow-up period in these preliminary analyses, the small sample accrued to date, or the fact that WEL is designed to assess confidence in various situations (e.g., depressed, anxious) that may not be impacted by personalization.  These analyses will be replicated with a larger sample using data obtained through the 6-mos follow-up.  New self-efficacy measures may be required to assess the impact of personalized dietary counseling.

Funding Sources: This research was supported by the American Heart Association.