A Novel Approach to Maintain Physiological Ketosis During Intermittent Fasting With the Consumption of a Fast BarTM and Coffee or Tea: a Randomized, Controlled Study

OBJECTIVES: Intermittent fasting has gained popularity in promoting health and been proposed to combat metabolic diseases. The study aimed to evaluate the effects of consuming a Fast Bar(TM) (FB) with coffee or tea in extending physiological ketosis associated with time-restricted eating (Clinicaltrial.gov: NCT04790552). METHODS: We conducted the study remotely during the COVID-19 pandemic with healthy adults. Participants were randomized into 4 groups: water-only fast (overnight for 15 hours), FB as a nighttime snack, FB + coffee or FB + tea in the morning. Blood ketone (BHB) and glucose levels were measured hourly for 4 hours (Precision Xtra Blood Ketone & Glucose Monitoring System, Abbott) after consuming study foods. Subjects also completed a satiety and mood survey. RESULTS: 84 of the 89 enrolled participants completed the study. There was no postprandial glucose increase after consuming the Fast Bar with either black coffee or tea. The mean (SD) BHB AUC(0–4) for nighttime FB, FB + coffee, FB + tea, or water-only fast were 1.40 (0.81), 1.22 (0.73), 1.11 (0.45), 1.36 (0.78) mM∙h, respectively. Despite a delay in BHB increase 1 hour after consuming the Fast Bar, the 4-h ketone and glucose AUCs of the Fast Bar groups were similar to those of subjects water-fasted for 19 hours (one-way ANOVA with Dunn's multiple comparison test). CONCLUSIONS: Fast Bar(TM) can be used as a nighttime snack, or with coffee or tea in the morning, to extend physiologic fasting state comparable to a 19-h water fasting. Fast Bar(TM) may be used to support intermittent fasting or time-restricted eating pattern while providing satiety. FUNDING SOURCES: Fully funded by L-Nutra, Inc.