Make an appeal to governmental authority. This study shows that we should limit fats in our diets and eat lots of carbohydrates to fight heart disease. You can trust it. It’s from the government! Right up until they change their minds, as seems to happen a lot with dietary advice. This is a variation on appeal to authority. This kind of argument has a built in assumption that government labs or government-funded researchers are disinterested practitioners of pure science. Unlike those corporations with their financial interests, government researchers are never pressured by politics or funding concerns to bias their findings. It all comes down to this: Uncle Sam said so. And you love Uncle Sam, don’t you? Well, your audience probably does.