Does food poisoning cause permanent damage? I heard in a study that it causes kidney damage, diabetes, and high blood pressure later on.

Specific cause. There is a particular bacteria e. Coli 0157 that can cause kidney damage and other serious issues. Most cases of food poisoning are due to other kinds of microorganisms and do not cause permanent damage.
Food poisoning. Food poisoning has various connotations. If you acquire HUS from ingested food, then the kidney will be injured. If you simply have diarrhea and vomiting but do not have HUS, then you won't have kidney damage - unless you suffer terrible dehydration and low blood pressure.