I am struggling with a similar problem (food, and gas in particular, affecting my sleep) and was wondering if you'd be willing to share more about your experience.
Sorry for such a late reply. For me the two biggest culprits are sulfites (increased sleep disturbances) and fructose (reduced deep sleep and more chaotic cycles).
What's weird about the fructose is I don't have the symptoms associated with such an intolerance; namely gas. Good news is that there is an enzyme (Fructaid) that helps mitigate it for me, so I don't have to completely cut it from my diet.
In the US, sulfites can be sneaky. Labels are required to list them if directly added to a product, but not for sulfite-containing ingredients sourced from a third-party. So the raisins in that trail mix very likely contain sulfites.