A January 2020 study by the University of Otago found that for some, certain types of diet and fasting can be, “healthful, beneficial ways to eat". The researchers said, “This work supports the idea that there isn't a single 'right' diet - there are a range of options that may suit different people and be effective. In this study, people were given dietary guidelines at the start and then continued with their diets in the real world while living normally. About half of the participants were still following their diets after a year and had experienced improvements in markers of health.”
"Like the Mediterranean diet, intermittent fasting and paleo diets can also be valid healthy eating approaches - the best diet is the one that includes healthy foods and suits the individual."
“Our participants could follow the [Mediterranean] diet's guidelines more closely than the fasting and paleo diets and were more likely to stay with it after the year, as our retention rates showed."