The claim isn't that everyone in nutrition etc is bought off. You simply don't need to do that. If you're in the sugar industry, you give funding to people inv

The claim isn't that everyone in nutrition etc is bought off. You simply don't need to do that. If you're in the sugar industry, you give funding to people investigating how saturated fat causes heart disease. You support organizations that back up your preferred theory. These orgs run media campaigns, slap a "heart-healthy" label on food products, and sometimes fund research. Forming popular consensus on "fats = bad" leads to additional funding from government or other charitable causes. Increased funding leads to an increased density of scientists working on the problem, which in turn increases the legitimacy of the field, especially among people just getting into their careers. If it's common wisdom in the cardio field that saturated fats are the worst cause of heart disease, that's where they're going to focus their efforts. It's one of those things where you simply don't need to buy anyone off. You just put your thumb on the scale early enough, and consistently push popular opinion toward a direction that's beneficial for you.