The staple food is preferably rice, and occasionally steamed sweet potatoes or corn cobs are also good. As far as bringing rice is concerned, rice is the best staple food, and steamed bread and pie are not suitable for bringing box lunch. From the point of view of microwave heating, the heated rice can basically keep its original state, but steamed bread and pie are easy to dry and are not suitable for microwave heating. Coarse grains, such as corn, sweet potato, Redmi and rice, can also be added to the staple food and cooked together. It tastes delicious and can supplement dietary fiber and vitamins. Even if it is heated twice, the nutritional loss of the staple food will be very small. Related to vegetables and bean products, the quality of meat is longer, and the content of protein is more, so you can bring some meat with you under the condition of ensuring freshness. It is suggested that it can be packed in a sealed fresh-keeping bag and frozen when it is not too hot. When eating, take out a bag, just enough for a meal, heat it at most once, and the loss of nutrients is limited. Try to choose beef, mutton and chicken with less unsaturated fatty acids. Pork is relatively rich in unsaturated fatty acids, so it is not suitable to be included in the box lunch category. Hairtail and seafood are not recommended, because it is difficult to keep the original color and flavor of fish and seafood by microwave heating, and it will also affect appetite from the appearance. Cooking methods suitable for microwave heating include steaming, stewing and stewing. The dishes made by these methods are not easy to taste and change color after being heated by microwave oven, while the fried and stir-fried dishes are obviously not suitable for microwave oven heating. Suitable for bringing rice: scrambled eggs with tomatoes, roasted eggplant, Chinese cabbage, soybeans, Chinese cabbage, bacon, bacon, smoked duck with salted fish, tender kidney beans, radishes, sweet potatoes and other classic dishes are all suitable. It is not advisable to bring food with high oil content. Sichuan-style pork, sweet and sour pork ribs, patties and fried rice are best not to be brought, because they contain too much oil and are relatively low-fat foods, which are more likely to deteriorate and are not easy to keep fresh. Because some green leafy vegetables contain more nitrate, if they are left for too long after cooking, nitrate will be reduced to nitrite under the decomposition of bacteria, which is carcinogenic and cannot be removed by heating. Among all vegetables, leafy vegetables have the highest nitrate content and melons are the safest. So cucumber, zucchini, pumpkin and wax gourd are all good choices. Cucumber vegetables are not only less harmful substances, but also easy to maintain taste and color, and the loss of vitamins is less than that of green leafy vegetables. In addition, solanaceous vegetables such as tomatoes and eggplants, stem vegetables such as lotus roots and carrots contain less nitrite, or potatoes such as potatoes and yams become healthy choices for people with rice. Scrambled eggs with tomatoes, roast beef with potatoes, braised eggplant, and fried dried beans with carrots and mushrooms are the classic menus of rice cookers. Finally, adding vinegar to cooking can also inhibit the production of harmful substances and preserve more nutrients. These dishes are not suitable for bringing rice 1, let alone out-of-season vegetables. Choose more novel fruits and vegetables and mushrooms, such as cucumber, tomato, carrot, wax gourd, pumpkin and mushroom. 2, cold salad should not bring rice, cold salad because of its own production process can not be completely exempted from health problems, easy to deteriorate after leaving overnight, easy to cause food poisoning after eating again. 3. Foods with high fat content, such as Sichuan pork, sweet and sour pork ribs, patties, fried rice, etc. , it is best not to bring it. Because these foods are high in fat and relatively low in fat, they are more likely to go bad and not easy to keep fresh. In general, don't bring green leafy vegetables for lunch. Because green leafy vegetables may produce nitrite after reheating, eating too much may cause symptoms of food poisoning such as nausea. Moreover, after reheating, green leafy vegetables lose more chlorophyll and nutrients, which is not good for health after eating.