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

Abstract

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.

Use of an mHealth Ketogenic Diet App Intervention and User Behaviors Associated With Weight Loss in Adults With Overweight or Obesity: Secondary Analysis of a Randomized Clinical Trial

“…This study is a secondary analysis of app use and outcome data from the intervention group of a previous mHealth-based randomized clinical trial [ 9 ]. The original trial examined weight loss and cardiometabolic risk between participants receiving the Keyto app paired with a breath acetone biofeedback device and those receiving WW International Inc’s WW app (formerly Weight Watchers International Inc is now WW International Inc) as an active comparator group over the course of 12 (primary end point) and 24 (secondary end point) weeks, as per registration on ClinicalTrials.gov (NCT04165707) and the published protocol (DERR1-10.2196/19053) [ 10 ].…”

“…As described previously [ 9 , 10 ], participants were recruited through web-based advertisements and an email listserv. Interested participants completed a web-based questionnaire to determine eligibility and, if deemed eligible, scheduled a phone call with a research team member to confirm eligibility and clarify any remaining questions.…”

“…The app provided to the intervention group was developed by a multidisciplinary team, including a cardiologist, an engineer, and a physician, and is commercially available. Details of the intervention have been previously described [ 9 , 10 ], but briefly, users are encouraged to follow a low-carbohydrate ketogenic diet with a focus on consuming fats from plant- (eg, olive oil and avocado) and fish-based (eg, salmon) sources that fit the Mediterranean diet pattern [ 7 ]. Users are not required to track their food intake but are encouraged to stick to recommended portion sizes and eat until satiety.…”

“…Participants were asked to weigh themselves daily on the study-provided Bluetooth scale. As described previously [ 9 , 10 ], baseline weight was considered the first weight measurement on the start day of the trial or, if no weight was recorded on that date, the weight measurement closest to 8 AM of the start date. The follow-up weight measurement was calculated as the average (mean) weight recorded across the final (ie, 12th and 24th) week of the intervention period to minimize the influence of daily weight fluctuations.…”

“…The app is paired with a hand-held device that measures acetone levels in the breath and serves as a noninvasive biofeedback measure of ketosis, while allowing for self-monitoring of dietary compliance and providing insight into how different foods affect fat burning and ketosis. In a previous randomized clinical trial, the app was shown to be effective for inducing weight loss and improving cardiometabolic health (ie, markers of glycemic control and liver damage) without worsening blood lipid profiles [ 9 ]. However, it is currently unknown how adults who are seeking to lose weight engage with the app and what might predict success of such a weight loss intervention.…”