Effects of 2-deoxy-D-glucose on food intake of rats are affected by diet composition

The effect of various doses of 2-deoxy-D-glucose (2-DG) on food intake in rats fed either a medium fat diet with a moderate carbohydrate content (MF-rats) or a carbohydrate-free high fat diet (HF-rats) was tested. Injections were given intraperitoneally either in the middle of the bright phase or 1 h after onset of the dark phase. During the light phase 2-DG induced a transient hyperphagia in both HF- and MF-rats, but the hyperphagia was somewhat less pronounced in HF-rats. During the dark phase 2-DG produced a hyperphagia in the MF-rats and a long-term hypophagia in the HF-rats. Since 2-DG elicited feeding in HF-rats during the light phase, the feeding response to 2-DG not only reflects hunger for carbohydrate as previously suggested but also seems to produce hunger for energy.