Of course! I didn't need a study for this result but it's good to read.
Junk food is ok, in moderation. Our kids view it as a treat, I'm happy with that. They feel extra special if they get dinner out.
Honestly, it's expensive and unnecessary.
Pack a lunch, just part of being a parent - save some money and feel good about it.
PS - Not my hat lol, it was Mason's after I dried him off