So many things can affect sleep, it might be related, it might not. The first year is basically one growth spurt on and off! Then there are the developmental leaps, teething... The list goes on.
As you're past 6 months, most people don't bother doing 1 food for a few days. If I only ate pears for 3 days and milk, I might feel a bit odd. Why not try a bit of variety?