IMO anything beyond 90 mins should have a gel pack as minimum.
I won't do a full meal as it's harder to ride your bike after. Your body can only process about 300-500 cals per hour so eating 1200cal lunch will sit for a long time. Plus make you ride slower and give a chance to stomach pains if not used to it and will suck worse on hills.
100-150cals in food per 30min is a good plan that works for me. Everyone is different and must try different foods. It's easy to start on Gel packs since they are about 100 each. As you get a hang of what the body needs, you can mix in a cliff bar (300 cals) or eat half every 30min.
On long rides I stop at the coffee shop and get a latte and a pastry of some sort. Usually the one with the most sugar LOL
My key foods on the bike
Banana 2-3 on weekend rides
Payday candy bars, don't melt and great for 3+ hour rides
Cliff blocks
__________________
Rule #10 // It never gets easier, you just go faster.