The reward for controlled eating.

While it is very difficult to fast, in many ways it is much harder to eat a controlled amount on a regular basis.  Once you start eating, it is very hard to stop.  When you avoid food completely you don't have to face food decisions.  For this reason, Hashem credits someone who eats in a controlled manner every day,  even more then someone who fasts.

From a Shiur by Rebbetzin Kalmonovitz "the true diet- Torah Haskafahs on food and Eating". Available from Shalheves