Elevated CART transcript levels were also found in normal-weight obesity-prone rats compared to obesity-resistant subjects, where the Arc leptin-CART pathway was proposed to respond to fat-rich dietary intervention through inhibiting excessive body fat accrual by substituting lipid storage with lipid mobilization (Rohner-Jeanrenaud et al., 2002; Wortley et al., 2004). This evidence concerns the gene CARTPT and obesity due to melanocortin 4 receptor deficiency.