In terms of food intake, mice from control and diabetes groups gradually increased from the 8th week after diabetes to the 7th day after seven-day rhFGF21 treatment, while mice from native rhFGF21 treated-group increased a small amount (from 69.3 to 75.1 Kj/d), but mice from PEGylated FGF21-treated decreased a small amount (from 71.7 to 64.0 Kj/d, Table 1). This evidence concerns the gene FGF21 and diabetes mellitus.