LEP and obesity due to melanocortin 4 receptor deficiency: This strategy prevented the development of obesity in the LRbCre/Bbs1fl/fl mice as indicated by the normalization of plasma leptin levels (3.0±0.3 ng/mL in calorie restricted LRbCre/Bbs1fl/fl mice vs. 3.1±0.5 ng/mL in control mice).