Keyto app and device versus WW app on weight loss and metabolic risk in adults with overweight or obesity: A randomized trial.

OBJECTIVE: The aim of this study was to determine whether a Mediterranean-style, ketogenic diet mobile health application (app) with breath acetone biofeedback is superior to a calorie-restricted, low-fat diet app in promoting weight loss. METHODS: Participants (n = 155) with overweight/obesity (mean [SD]: age 41 [11] years, BMI = 34 [5] kg/m2 , 71% female) were randomized to one of the interventions delivered entirely via app. Participants received a wireless scale and were instructed to take daily weight measurements. A third-party laboratory collected blood samples at baseline and 12 weeks. RESULTS: Weight loss at 12 weeks was greater in the ketogenic (-5.6 kg; 95% CI: -6.7 kg to -4.5 kg) compared with the low-fat group (-2.5 kg; 95% CI: -3.6 kg to -1.4 kg) (between-group difference: -3.1 kg; 95% CI: -4.6 kg to -1.5 kg; p < 0.001). Weight loss at 24 weeks indicated durability of the effect (between-group difference: -5.5 kg; 95% CI: -8.3 kg to -2.8 kg; p < 0.001). Secondary/exploratory outcomes of hemoglobin A1c and liver enzymes were improved to a greater extent in the ketogenic diet group (p < 0.01). CONCLUSIONS: Among adults with overweight/obesity, a ketogenic diet app with breath acetone biofeedback was superior to a calorie-restricted diet app at promoting weight loss in a real-world setting.