Banning tobacco, although it's wrongfully intrusive, would at least have ONE good effect: a reduction in the incidence of several diseases. But attacking dietary fat won't do any good at all -- It's now been established beyond all question, that obesity, and the secondary complications of obesity such as heart disease, diabetes, etc, are triggered by the body's reaction to carbohydrates -- NOT FAT. I repeat, eating fat doesn't make people fat -- excess carbohydrates (sugar, starch), when combined with a genetic susceptibility, makes people fat.
The anti-fat, anti-meat crusaders don't want to hear this. They'll argue til they're blue in the face, and they'll never consider the evidence, because their real motive is NOT our health, but serving a vegetarian ideological agenda. (Anti-smoking crusaders probably aren't motivated by health, either. But at least their advice is medically right.)
You're right that they don't care about people's health. But I think their true agenda is to get the tax revenue so they can finance all their leftist, social-engineering programs (animal rights, global warming and especially ... income redistribution).