Objectives: The goal of this study was to assess changes in serum immunoglobulin G (IgG) food antibody titers and quality-of-life measurements following a targeted elimination diet in overweight/obese adults.
Methods: We performed a randomized control trial. Participants were randomized in a 2:1 ratio to either an intervention group or waitlist group for 3 months. Food IgG testing was performed on all participants. The intervention group was instructed to eliminate up to 10 foods, for which they had high titers of IgG and communicated with health coaches for nutritional counseling for meal planning and adherence. The waitlist group did not receive their IgG testing results or health coaching. Primary outcome was serum IgG titers for foods eliminated during the trial, compared with baseline concentrations. Secondary outcomes were health-related quality of life measured by Patient-Reported Outcomes Measurement Information System (PROMIS-29) and change in participant-identified symptom severity measured by Measure Yourself Medical Outcome Profile. Exploratory outcomes were changes in body weight and waist circumference.
Results: IgG antibody concentrations decreased in 83% of the targeted foods in the treatment group and in 60% of the foods in the waitlist group, but this was not found to be a statistically significant difference. The intervention group reported improvement in sleep during the trial compared with waitlist, which was the only statistically significant finding in the study.
Conclusions: The findings are consistent with changes in IgG titer measurements following an elimination diet based on IgG testing. Future larger clinical trials are necessary to determine the degree to which these findings are generalizable.
Keywords: IgG test; elimination diet; food sensitivity.