1. Yes, they absolutely play a role in obesity. People think that the restaurant size portion is a normal size. THe portions probably have increased because we want to get the most for the money. Also, plenty of food is seen as generous or hospitality displayed. Everything is bigger and better in America!
2. I believe that it is both the customer and restaurant's responsibility and problem. Obesity is a massive epidemic that effects health care dollars, spending, higher premiums for insurance. health of workers, etc. Ultimately though the responsibility is with the consumer. You are not forced to eat at any particular place and you are not forced to clean your plate.
3. The power of advertisement is huge! That is why it is a multimillon dollar industry just in advertising. Places that are offering more healthy choices are doing well. However, advertising has not caught up with them yet to make a huge impact. So that would be one area to help is to increase positive advertising. Educating on the proper size of portions. Decreasing the incentive for Super Sizing everything and making it look so attractive. Offering a variety of side dishes that are healthy and colorful presentation. With children offer theme plates, be decorative with food design and presentation!
Two things for the consumer to do, Is use a salad plate at the buffets, ask the waiter not to bring bread to the table so you are less likely to eat it. Avoid buffets altogether! Ask for a to go container right away and put half of the food in it to eat at another meal.
OK that was more than 2 things ! ha!