INS and Insulin resistance: However, if it is correct that they do become insulin resistant, this might be because insulin resistance is less likely to be a problem in animals that largely suspend feeding and suppress their metabolic rates (Carey et al., 2003; Storey and Storey, 2004; Heldmaier et al., 2004) for several months when they are most obese, in contrast to voles that remain active and have high levels of energy expenditure year round (Jackson et al., 2001; Speakman et al., 2003; Liu et al., 2003; Li and Wang, 2005; Wu et al., 2009).