you have to eat
Para mejorar, tienes que comer.
To get better, you have to eat.
Tienes que comer con regularidad.
You need to eat regularly.
Para perder peso tienes que comer menos dulces.
To lose weight you have to eat fewer sweets.
You have to eat the toast.
No tienes que comer si no quieres.
You don't have to eat if you don't want to.