Relation of breath methane with obesity and other factors.

In a study of breath methane concentration 43 percent of males and 49 percent of females produced detectable amounts. The proportion of methane producers increased significantly with age in males but not in females. Obesity as measured by the sum of triceps, forearm, suprailiac and subscapular skinfolds was significantly less in producers than non-producers. Amongst methane producers there was also an inverse relationship between skinfold thickness and the breath methane concentration. Breath methane concentrations were lower in males than females. In addition, a higher proportion of methane producers was found amongst secretors of blood group substances (ABH antigen) than non-secretors.