Cheap sugar substitutes will be used. Long term health effects are not clear.
What you want is a calorie tax. Possibly a liquid calorie tax.
Or just every calorie?
The problem is sugar tastes good. Taxing processed sugary foods will certainly help, but are you also going to tax, say, sugar in a bag? If so, you have effectively banned Grandma's cookies. Do you want to be known as the politician who effectively banned home-cooked baked goods?