There is increasing evidence that the glycerol channel, aquaporin 7(AQP7), has an important role in adipose tissue formation and function--deletion of the gene in a mouse strain leads to obesity and diabetes type 2 if the mice are aged or fed earlier with a high-fat or sucrose diet. Can increased levels of AQP7 in adipose tissue protect against obesity? New studies on AQP7 highlight the important role of glycerol transport in the development of obesity and metabolic disease.