people regularly buy groceries from three to seven different stores.
Yes, but some families may buy specific items from specific stores depending on prices and quality of the food. That doesn't necessarily mean they are more prone to overbuying? Where is this proven?
“If you’re shopping more frequently, you can purchase food that is meant to be eaten in a shorter time frame.”
But what about if you buy something that tends to go bad quickly (like fruits or vegetables)? You may be buying them for a couple days but they won't always get eaten in that time, therefore still having the issue with throwing the food out.