1. Seafood, fish, shellfish, etc. Not suitable for overnight storage. For example, shrimps, crabs and various fish are prone to produce protein degradation products overnight, which is harmful to health.

2. Green leafy vegetables are also not suitable for storage. Green leafy vegetables contain different amounts of nitrate. If it is heated or stored in the microwave oven for too long, vegetables will easily deteriorate and then turn into toxic nitrite, which has carcinogenic effect.

3. Bread, steamed bread, cakes, noodles and other flour products are not suitable for storage, such as lunch boxes.

Perishable food is not suitable for lunch, such as tofu and brine.

So what food is suitable for heating in a lunch box?

Experts suggest that the staple food is rice, and the suitable dishes are eggs, melons, tomatoes, eggplant, salted fish and general meat. Be careful not to overcook the fruits and vegetables when preparing the lunch box, so as to reduce the loss of nutrients when reheating. Pay attention to thoroughly heating lunch before eating.