Your guess is absolutely correct: lo que= what. Eg. - Me como lo que me gusta = I eat what I like. - Siempre pregunto lo que no entiendo = I always ask what I don't understand. I would just correct your sentence: Voy a comer lo que él se coma. Saludos

Hola JmmiP. La estructura <lo - pronombre neutro> + <que - pronombre relativo> se utiliza en español para explicar o resaltar la proposición anterior. En inglés: What Por ejemplo: • Mis amigos no vinieron a la fiesta, lo que no sé es por qué. • Lo que quiero decir es que no voy al cine con vosotros. (En este ejemplo no hay proposición anterior escrita, pero se supone que antes hubo una explicación ) Saludos. Antonio

Just a curiosity. There are some places in Spain, for example in Extremadura, especially in Badajoz, where people use this expression in a question: ¿Lo qué? It is not considered good Spanish practice, but it is very frequent there, and it means: What?, when they do not understand something you are saying.

Yes, It's not "come"as you need to use the subjunctive, which is "coma" for the third person. And it's not "comeré" for many reasons, first, "comeré" is the conjugation for the first person "Yo comeré", in case it was possible to say it it would be "el comerá". But the latter is not possible either as it doesn't sound well, i think because first you say "voy a" and the simple future doesn't work well in this case. The sentence "lo que él (se) coma" itself expresses future time already, in a way. Hope it helps you!