Health advocates, rightly, have long been wary of the market and its promoting of consumption. Think of cigarette companies and their predatory practices, especially aimed at children, until they were stopped because of public outcry and various regulations. In terms of the food and beverages industry there are many questionable practices. Just one example: Advergames -- online activities targeting kids using fun to promote a brand of food etc, and positive associations with it.
But the market does respond if consumption patterns change. Over the last decades rates of smoking in Canada and the United States have fallen substantially and, of course, so too have the sales of cigarettes. (They are still peddled aggressively in other countries but that is another story.) Consumers' choice in alcohol, and thus its marketing, have also changed in recent decades; much more wine is consumed now in the United States and Canada than several decades ago.
Now there is some evidence that consumers are turning away from at least some forms of junk food and beverages. To the extent this is so the market will respond. One piece of evidence is the falling rates of soft drink (soda) consumption.