Food intake (FI) can be predicted on the basis of variables that describe food quality, the environment and the animal. Live weight (LW), in some form or other, is usually the only variable used to describe the animal. Animal fatness, estimated by condition score (CS), can affect intake at a given LW. A simple model to account for that is FI= a.LW.(1-b.CS) with FI in g/day, LW in kg and CS in units of a scale up to 5. It is evident that food quality will affect parameter a. Here we test the hypothesis that the parameter b in this model is significant but not affected by food quality. To that end, we measured LW, CS and intake of three different foods with ewe lambs that showed a large variation in LW and CS as a result of different nutritional histories.