It is recommended to go to big supermarkets and big farmers' markets to buy food, because there are barriers to entry. When eating out, eat less oily vegetables (such as boiled meat).
Cheap, too gaudy things may usually add chemicals because of low cost, while too expensive food will also lead to great motivation for adulteration because of high profits.
Try to choose a bigger face and eat everything with it. On the one hand, it can balance nutrition, on the other hand, it is also conducive to spreading risks and avoiding toxin accumulation.