Tracking How Meals Affect Metabolism At Home

“Ours is the first study to investigate the practical use of this breath device. What makes this technology interesting is that up to now, the only way to assess metabolic function has been under laboratory conditions using advanced and expensive respiratory analyzers,” says lead author Dr. Justin Roberts, Associate Professor in Nutritional Physiology for Health & Exercise at Anglia Ruskin University (ARU).

This study was split into two parts with the first confirming the effectiveness of the device under controlled lab conditions using the gold standard respiratory analysis Lumen and Douglas bag air testing. Testing involved 12 healthy participants who ate a high-carb meal after fasting who then had respiratory measurements taken at rest as well as at 30 and 60 minutes after their meals with the bag test. 

Lumen can capture the percentage of carbon dioxide as the user breathes out. Results revealed a significant increase in CO2% within 30 minutes of eating the meal, the increase measured by the Lumen displayed a link to an increase in respiratory exchange ratio (RER), meaning that the device can detect an acute change in carb consumption. 

The team investigated if the device could detect metabolic changes while eating a normal diet as well as a high or low-carb diet over a one-week period for the second part of the study. This testing involved 25 healthy active adults who took measurements at home using the Lumen at scheduled points each day to demonstrate how the device could fit into a normal lifestyle. According to the researchers, the device could detect changes in CO2% over the timeframe in response to acute dietary changes, but it was not sensitive to day-to-day changes suggesting that it might be better for tracking long-term dieting results. 

“When people leave the lab there are limited means to accurately assess metabolic changes at home, such as fuel use and whether the person is likely burning more fat or carbohydrates, either in response to a diet or exercise. Therefore, the findings from our study demonstrate that a home-use portable device like Lumen could be a useful way of tracking weekly changes in dietary interventions when dietary carbohydrate is the main variable being changed. It should be noted that our study only tracked for a short period, therefore longer-term studies are needed to assess whether the device can detect metabolic adaptations over time,” explains Dr. Roberts.

Dr. Roberts also noted that metabolic adaptations and interpretation of data on a day-to-day basis can all be different, so potential users must keep the levels of nuance with metabolism in mind when using the device. 

“However, the Lumen device could be a useful tool to support research and dietary interventions. It may offer a practical solution to tracking dietary changes, particularly in relation to regular exercise, but users should be mindful of the complexity of metabolic adaptations and interpretation of data on a day-to-day basis.”