You’ve received good advice, and agree with everything that’s been written so far.
I specifically want to reinforce what DocPixel and PrintDriver mentioned. Presbyopia (farsightedness) starts to affect most people’s ability to focus at typical reading distances over the age of 40.
Since the majority of your target audience is within that age group, I’d definitely make the type large enough to minimize the number of these people who need to locate their reading glasses before deciphering what’s on the flyer/menu.
As for content, if you want people to keep the flyer, put something important on it, like the entire menu with brief descriptions, prices, phone numbers, URLs and coupons to use for their next take-out order. People will tend keep it as reference for later if it’s something more than just an advertisement.