JMIR Publications

ABSTRACT

Background:

The increasing prevalence of obesity and related metabolic disorders has highlighted the need for innovative tools to monitor and manage metabolic health. The Lumen device offers a novel approach to assess metabolic state through exhaled carbon dioxide (CO2) measurements.

Objective:

This study aimed to investigate the association between the previous day's carbohydrate consumption with fasted exhaled CO2 levels in Lumen users, while also examining the influence of fasting duration, BMI, age, and gender on these measurements.

Methods:

We conducted a retrospective observational study using deidentified data from 48,058 Lumen users, comprising 707,373 fasted sessions. A linear mixed model was employed to analyze the relationship between fasted %CO2 levels and reported carbohydrate intake, fasting duration, BMI, age, and gender.

Results:

The analysis revealed that higher carbohydrate intake from the previous day was significantly associated with increased morning %CO2 levels (β=0.029, P<.001) and longer fasting duration was linked to decreased %CO2 levels (β=-0.017, P<.001). Higher BMI (β=0.018, P<.001) and increased age (β=0.006, P P<.001) were associated with higher %CO2 levels. Additionally, female users exhibited higher %CO2 levels compared to males (β=-0.113 for males, P<.001).

Conclusions:

The Lumen device effectively detects changes in fasted %CO2 levels based on the previous day's carbohydrate intake and fasting duration, as well as individual characteristics such as BMI, age, and gender. These findings suggest that Lumen could be a valuable tool for personalized metabolic health monitoring and management, offering insights into the impact of dietary choices and fasting practices on metabolic state.