Once again the government is trying to control our freedom of choice
How far will they go to control the citizens into behaviors they deem 'correct'? We might as well let the government control our food sources and provide us the food they think we should eat. We could just drive up to the government run grocery store and they'd have our groceries already picked out for us (why let us choose?). Yeah, sounds extreme but it sure seem like they want to control what we eat. Find a different way.
Also, what about us that are not obese or overweight, do we get a tax exception? I'm 37, 6' 2" 165 lbs. and I can eat anything I want and won't gain any weight. Why should I pay an 'obese tax'?
