In Obese: Radical Idea: how about a tax break for someone who cuts down body

Had a random idea in my head: Since America is the fattest nation in the world, how about a tax break for someone who reduces his/her body fat? In case of children under age of 17 (since theyre not working) their parents get a tax-break. Monitoring sodium content in food? I know some libertarians may explode sayin, " i dont want govt tellin me how much salt i need in my food". How about I have ~7% ...Obese