Obesity and Soft Drinks

Unlikely to have an impact, but worth evaluating!

Also might not reduce obesity for other reasons - but not the only metric on which to evaluate the policy

How much substitution not clear. Closest extant empirical evidence relates to soft drink taxes.
-see background information here

Sugary drinks are subsidized by U.S. farm policy and are an important factor in overweight among children, leading to overweight adults.

Literature suggests otherwise.

This is surely something that is worth studying empirically. I can think of good arguments on both sides and have no idea what would happen.

I don't have the necessary knowledge to handle this one.

Michael Anderson has done research partially related to this that shows that people are able to substitute across sources of calories easily
-see background information here

Probably. Though proximity to fast food restaurants seems to matter, as if substitutability is limited.
-see background information here

Seems unlikely this one change on its own would *significantly* reduce obesity.

Is there any empirical work on this issue?

Bad question. Taxes unlikely to work if low but big cigarette takes reduce consumption and peoplle don't substitute other smoke!

There will be substitution & I don't like the paternalism, but there is growing evidence that such nudges can be effective.

This is a question a psychologist is better at answering. Are people aware of all the calories they assume? I do not think so.