You need to think of food waste as more than "leftover food". When you toss spoiled food, time, energy, and resources from the initial planting of food through harvest, transportation, storage, preparation, and then disposal needs to be calculated.
How to Reduce Food Waste
I guess the meal delivery kits reduce food waste by keeping leftovers to a minimum - both from the actual meals and the measured raw ingredients used to prepare the dish. We, personally, toss very little food. Actually, we toss very little anything, period. If you guys saw how little trash is in our 96-gallon trash cart every other week (because the companies around here do not offer once-a-month trash pick-up), you would be amazed.