Actually, I'm not in favor of banning either. I'd much prefer starting with first eliminating any and all benefits companies that produce unhealthy food enjoy, starting with farm subsidies that greatly disadvantage healthy foods like fruits and vegetables.
Once that is done, I would take items that are known health hazards and classifying them as toxic for consumption such as HFCs and hydrogenated oils. They are basically slow acting poisons. You would still be able to buy them and use them in your own home as an individual citizen, but food companies cannot buy them and use them to make food. Instead they need to use the healthier alternatives by default. This way all the junk food we enjoy today would still exist, but we would mitigate how unhealthy they are for us, since food companies would have to use the least unhealthy recipe possible.
I see this as reasonable since it preserves individual freedom, but prevents corporations, which have a fiduciary duty to psychopathy, from producing maximally unhealthy foods in search of a profit.
If those least unhealthy options were still economically attractive to the poor after the elimination of food subsidies and classification of cheaper, less healthy substances as unfit as an ingredient in manufactured foods, I would then look into how to incent people to choosing the healthier alternatives.
I think the best option here would be to make it easy for a family to acquire a cheap slow cooker and recipes and subsidize a ready-made pack of food that contains spices and other bulk ingredients used in the slow cooker recipes. The latter option is already done in Brazil under the name "cesta basica". Here's an image of the foods included in the "cesta basica"
http://www.utahpreppers.com/wp-content/uploads/2008/12/cesta...
You can feed an entire very well for very cheap on it. It's also available to everyone regardless of income.
