Our customers want mediocre food cheap. Every time we release a higher priced but higher quality product, the people who said they would pay for it… never do.
You say you want more fruits, salads, organic, all natural, etc. well then start buying that stuff and stop buying double cheeseburgers. Our best selling stuff is always whatever we can make taste good, at rock bottom prices.
We've actually learned not to listen to our customers when it comes to a lot of things. Health nuts won't come into McDonald's to eat even when we give them what they want.
As entrepreneurs we cannot blindly listen to our customers. They lie to us. Here's my old post titled Listening to Customers is Harder Than it Seems.
Given that customers lie, sometimes we have to extract information indirectly. Instead of asking customers how much they would pay for a hypothetical product, ask them how much they're currently paying for however it is they're solving the problem that you are trying to solve.
Other times, it can work to ask a direct question but discount the words that come out of their mouth and pay attention to body language. It would be fun to come up with a list of questions that elicit non-useful verbal answers but useful body language answers. In the past I've proposed, "Do you have self-confidence?" Steve Jobs asks employees, "Why are you here?"
Finally, actions speak louder than words. Just as your calendar never lies — how you spend your time says more about your priorities than your stated priorities — what customers actually buy and do is more instructive than what they say they'll do.