Is salt bad for you? (hint: unless you have a very specific hypertension condition, all the bad things you heard about salt are not relevant to you)
How much is too many eggs per day? (hint: no known limit. Cholesterol from eggs was never shown to be a problem)
Well, how about butter and fat? (hint: right kind of butter is good for you, as is the right kind of fat)
But surely, saturated fat is bad for you! (hint: no proof of that)
But at least bacteria and dirt are bad for you, I'm sure of that! (hint: life span is correlated with eating lots of fermented - i.e. bacteria laden foods. Also, people who work in sewage have higher life span and less illness overall)
You are taking tens or even thousands of bets based on bogus research without even knowing that. It is not unreasonable to assume that washing your hands all the time and keeping your house clean significantly raises the probability of autoimmune disease.
And really, if you go through nutrition literature and try to trace the knowledge to repeatable and demonstrable experiments, you'd agree with "very little". e.g., the calorie marking system used on foods is based on bomb calorimeter experiments (which you can debunk at home) and atwater factors (which have been shown to be grossly inaccurate, as in tens to hundreds of percents).