Estimation of body fat in normal and obese mice

There is at present an enormous interest in the mechanisms which serve to regulate food
intake and lipid deposition and thus the causes and effects of obesity. There are a number of
animal models of obesity which are the subject of intensive study; in rodents obesity may be
induced by chemical agents such as gold thioglucose (GTG; Brecher & Waxler, 1949)
and bipiperidyl mustard (BPM; Rutman et al. 1966), by providing pleasant-tasting food or
sugar solutions (Kanarek & Hirsch, 1977) or by genetic inheritance as in the ob/ob mouse
and Zucker fatty rat (Bray & York, 1971). However, obesity as defined by an excessive
accumulation of fat (Davidson et al. 1975) is not always associated with a high bodyweight
(Larsson, 1967; Rogers et al. 1979) and therefore an objective measure of adiposity
should always be used as the criterion for obesity. Direct measurement of body fat in the
mouse involves drying and extraction procedures which are not only time-consuming but
also destructive, precluding for example histological examination of organs. We now report
experiments in which a number of methods of indicating obesity are assessed to determine
whether they are reliable indices of obesity and also whether they are sensitive enough to
give an accurate estimate of the body fat content of normal mice which have a comparatively
narrow range of body fat contents. Preliminary results on a normal population have
previously been communicated (Webb & Rogers, I 979).

Citation:
Rogers, P.; Webb, G.P. (1980) ‘Estimation of body fat in normal and obese mice’ British Journal of Nutrition 43 (1) 83-86.