Bad cherry picking used only to promote your own point. What about the enormous amount of good advice that has changed our lifestyles over the past century? Do you even know how people lived 100 years ago, how they ate?
What you should say is "some health experts have a habit of not always promoting scientifically sound advice, and many times promoting ideas that fly contrary to evidence. Fortunately as more evidence is gathered, those 'experts' are discredited and a better understanding of nutrition is the result".
When you don't cherry pick, you can find sources like:
The Harvard School of Public Health's Nutrition source. By any metric, "health experts promoting ideas". http://www.hsph.harvard.edu/nutritionsource/
Can you take issue with these health experts providing advice? Anything they recommend that you think is grossly wrong? Because this is scientifically validated nutrition advice from health experts, the very thing you're trying to discredit by screaming "trans fats and cigarettes" as if those complex cases invalidate an entire scientific field of study.
Honestly, you're trying to smear the name of "experts" in general, without separating "health experts" (medical doctors, nutritionists, idiot laypeople who label themselves naturopaths, etc) from scientists. I feel like you're trying to find a way to ignore the entire science of nutrition because you got burned listening to a fad or because big tobacco ran roughshod over science six decades ago.