title: Measuring breath acetone for monitoring fat loss: Review.
abstract: OBJECTIVE
  Endogenous acetone production is a by-product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters.
  
  
  RESULTS
  BrAce can range from 1 ppm in healthy non-dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement.
  
  
  CONCLUSIONS
  When biologic factors are controlled, BrAce measurement provides a non-invasive tool for monitoring the rate of fat loss in healthy subjects.
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Anderson
mesh_terms: D000096:Acetone / Q000032:analysis* / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D001944:Breath Tests; D031204:Caloric Restriction; D003920:Diabetes Mellitus / Q000378:metabolism; D016883:Diabetic Ketoacidosis / Q000175:diagnosis* / Q000378:metabolism; D045853:Exhalation / Q000502:physiology; D005215:Fasting / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology; D008991:Monitoring, Physiologic / Q000379:methods*; D015431:Weight Loss
chemical_list: D000096:Acetone