Maybe you've heard the commercials for 3conomics by a certain fast food company.
Here's a personal story of another fast food chain and how they run things.
I order a Jumbo Burger and a soda (needed food on the run before evening Urgent Care clinic since I didn't make any sandwiches for the day.) She tells me "Would you like to get our Jumbo deal? You'll get fries and two tacos with it and it will be cheaper." (emphasis mine!)
BWA? I hesitated because I'll be honest, I was tempted. Ooh, more food for less money? I turned it down knowing that my stomach could not hold more than a burger. Besides, America is fat enough as it is. I needed to take a stand.
"Just trying to save you money," she told me.
"Well, I think it's ethically irresponsible for your restaurant to offer more food for less money. I'll eat what I can eat." I replied.
She cocked her head to the side, obviously surprised to be under attack by proxy, but conceded. "Yeah, sorry," she said as I drove off.
By the way, the burger was delicious. I went home that evening and had a salad with carrots to make amends. :)