Oxygen Consumption and Body Fat Content of Young Lean and Obese (OB/OB) Mice

Abstract

Rates of O2 consumption were determined daily from birth to 19 days of age and weekly thereafter until 16 wk of age in lean and obese mice. As early as 5 days after birth obese mice consumed less O2 than lean mice. Obese mice weighed more than lean mice by 6 days of age and contained 38% more fat than lean mice at 7 days of age. At 14 days of age obese mice contained 53% more fat than lean mice. Beyond 3 wk of age O2 consumption of obese mice was less than observed in lean mice when the results were expressed per gram body weight, but the values for obese and lean mice were similar when expressed per animal. Apparently alterations in energy metabolism occur very early in the life of obese mice.