Right, but the keyword there is 'nudge'. If you are already having headaches and high blood pressure due to your diet, your diet should have been modified long

Right, but the keyword there is 'nudge'. If you are already having headaches and high blood pressure due to your diet, your diet should have been modified long ago. Similarly when people have cardiovascular issues and atherosclerosis, the time to change things was likely decades ago, not after they've already damaged their body so much. Sometimes these 'nudges' help patients, but getting someone to significantly alter their life is very hard.