It depends on what those calories are. If you're eating inexpensive veggies/fruits/starches/grains, you're probably around 200-300mpg equivalent on a bike. If you're eating steaks, then you're probably pretty close to a car.
You're doing a lot worse than that if you're hauling mail around.
The numbers also get a lot worse once you consider the energy cost of shipping your food to you (as both your article and the person you were responding to noted).
