but sugar is often the main or even only issue, because it bypasses your normal "im full" pathways. It's also deceptively easy to take a balanced amount of calories and tip it. Add one soda a day to a balanced diet and you end up with 10lbs excess weight per year.
Id wager for many people struggling with weight that sugar is the main and perhaps even only problem.
That's part of the issue with policy - often it's not getting at the real heart of the problem.