[Question] Genuine question: If Eliezer is so rational why is he fat?

So I recently had a lot of fun reading HPMOR and the sequences, and I feel like I learned a bunch of cool things and new ways of looking at the world! I’ve also been trying to get my friends interested in the rationality community, particularly through the works of Eliezer. There, however, appeared an unexpected obstacle in my way. My friends saw a picture of Eliezer and immediately wondered, “If Eliezer is so rational (at least relative to other people) and also has living as long as possible high on his preference ordering, why is he fat?” It does seem like something that ought not take that much effort but has an overwhelmingly positive impact on one’s life. health-wise, and maybe even performance-wise. I initially jokingly brushed the question off, saying his work is too important and doesn’t leave him enough time to optimize his health, or that maybe he has some condition that prevents him from losing weight.
But the question stuck with me.