Here's what you should order from Chipotle, McDonalds, and 12 other fast food chains for lunch if you don't want to fall asleep at work

While we know that what you eat for lunch affects your productivity for the rest of the day, this doesn't mean you have to rule out convenience for the sake of healthy choices.

Plenty of chains offer meal options that are heavy on the protein and healthy fats and easy on the carbs and bad fats, which is just what you need to avoid the 3 p.m. slump, says Lisa De Fazio, a healthy lifestyle expert and registered dietitian.

Take Chipotle for example: An oversized burrito is probably not the best thing for your productivity, but bowls and other less carb-heavy options with lots of protein and healthy fats like avocado will give you just what you need to feed your brain without overdoing it, DeFazio says.

De Fazio recommends these healthy fast food lunch options that will keep you from passing out at your desk: