Society pays for it too. Less so than some countries given America's private healthcare system, but as an extreme example... what happens if America needs more

Society pays for it too. Less so than some countries given America's private healthcare system, but as an extreme example... what happens if America needs more soldiers? Overeating means more agriculture means more land used/more inputs required/more carbon burned. Illness and early deaths has an impact on productivity. No man is an island, everything you do has an impact on society.