"Pre-prepared meals enter campuses" has become a hot search! How harmful is it to the body to eat pre-prepared meals frequently?

You happily go out to eat, but the restaurant provides you with pre-prepared dishes instead of freshly cooked dishes... Can you accept this? In recent years, pre-prepared dishes have gradually entered the public eye because of their convenience and speed.

However, there are also many controversies about it. Recently, the issue of "pre-prepared meals entering campuses" has caused widespread discussion, and parents in many places have expressed their concerns on major platforms.

Image source: a social platform

So what are pre-prepared meals? Are they harmful to the human body? Can we eat them? Today we will talk about the issues that everyone is concerned about pre-prepared meals~

What are pre-prepared meals?

Pre-prepared meals, also known as cooking packs, are made by pre-processing edible raw materials into semi-finished or finished products , and then adding various auxiliary materials as needed. Food additives may be used. They have the characteristics of a long shelf life and convenience of consumption.

In terms of type, pre-prepared meals are generally divided into four categories: ready-to-eat foods, ready-to-heat foods, ready-to-cook foods, and ready-to-prepare foods. [2]

For example, the dried tofu and chicken breast that we usually eat right after opening the bag are ready-to-eat foods; instant noodles that need to be soaked in hot water or heated before eating are ready-to-heat foods; fish-flavored shredded pork and braised pork with preserved vegetables that can be served after simple cooking are ready-to-cook foods; stir-fried dishes made of clean vegetables, clean meat, and auxiliary ingredients that are packaged according to quantity are ready-to-prepare foods.

Chicken breast ready to eat after opening the bag. Image source: Nutritionist Gu Zhongyi

Most of the takeaways we order are made from ready-to-cook foods , with short waiting times and fast delivery.

Pros and cons of pre-prepared meals

Pre-prepared meals that are popular with most people are not perfect just because they are quick. They have advantages as well as flaws.

advantage:

①The difference between pre-prepared meals and ordinary home cooking is that they eliminate the processes of buying vegetables, washing vegetables, and cutting vegetables. They do not require too much time to prepare and cook food, saving a lot of energy and are very convenient.

② For catering operators, pre-prepared meals can save manpower, space and costs to a greater extent, and the food can be served quickly, so diners do not need to wait too long, especially for take-out.

③ Food safety is relatively more guaranteed: Compared with catering stores, pre-prepared meals produced by regular manufacturers are safer and more reliable in terms of ingredients.

On April 27, 2022, the first national group standard "Specifications for Quality Evaluation of Pre-prepared Meals" was officially released in Nanjing. It regulates food raw material procurement, production and processing, packaging requirements, shelf life and best tasting period, storage, distribution and other aspects, and also encourages the traceability of food raw materials .

On June 17, 2022, the inaugural meeting of the World Federation of Chinese Cuisine's Pre-prepared Food Professional Committee was held in Huai'an City, and the "Working Regulations of the World Federation of Chinese Cuisine's Pre-prepared Food Professional Committee" was formulated. This has gradually made the pre-prepared food market more standardized and the food ingredients safer.

shortcoming:

① For families, if pre-prepared meals become the main choice for three meals a day, families will lack the daily chores of shopping, picking, and washing vegetables with family members, and will not be able to experience the complete cooking ritual.

② In addition, the taste of pre-prepared dishes is uniform, which is pre-prepared according to the taste preferences of most people after investigation. It cannot realize the personalization of taste and cannot meet the taste needs of different people. For example, if you choose a braised lion head dish, whether you eat it at home or order takeout, it will taste the same, and you can't taste the "taste of mom or the taste of home".

③The taste is not as good as freshly cooked dishes. After all, its raw materials have been heated once, and after diners buy it, it has to be heated again, which will affect the taste.

④ In addition, many pre-prepared dishes are preserved by freezing. The ice crystals condensed from the water during the freezing process will change the taste and texture of the food to a certain extent, making the food taste a bit "powdery".

⑤ Pre-prepared dishes may not taste as good as fresh dishes. Some people have studied the flavors of commercially available fried fish-flavored pork shreds and fish-flavored pork shreds in cooking bags. The results show that the overall "fish flavor" of the two is similar, but there are also certain differences. Sulfur, nitrogen and other heterocyclic compounds have important contributions to the "fish flavor" and "meat" aroma of fish-flavored pork shreds. Although the types of heterocyclic compounds detected in the fish-flavored pork shreds in cooking bags are more than those in commercial dishes, the content is lower, which makes it difficult for some specific flavor substances to form, resulting in the meaty and fermented aroma in the cooking bags being lower than that in commercial dishes. [3]

⑥ The nutrition of pre-prepared meals is relatively simple. Most of them are meat dishes. Even if there are vegetables, the types are also limited. Common vegetables are carrots, peas, bamboo shoots, potatoes and other vegetables that have a long storage time and are not easy to change color. There is a lack of green leafy vegetables.

The biggest problem with long-term consumption

Although pre-prepared meals are convenient and fast, they have captured the hearts of many office workers and kitchen novices. However, it is still not recommended to eat pre-prepared meals for three meals a day for a long time. There are mainly three problems:

① Malnutrition: As we mentioned above, due to the limitation of food ingredients, the nutrition of pre-prepared meals is relatively simple. Although carbohydrates, proteins and fats are well guaranteed, it is difficult to retain more vitamins, minerals and bioactive ingredients.

These ingredients may be lost during the processing process, such as washing, high-temperature sterilization, and transportation. When they reach the hands of diners, they will be reheated, causing more nutrient loss. In addition, the staple food of pre-prepared dishes is mostly white rice, which makes it difficult to achieve a combination of coarse and fine grains.

② May make you gain weight: Many pre-prepared dishes are high in fat and calories in order to cater to the public's tastes and have a longer shelf life.

For example, if you look carefully at the nutritional composition table of the boiled beef in the picture below, you will find that its fat content is as high as 16.1g/100g and its protein content is 6.5g/100g. The details page introduces that the main ingredients are beef hind leg meat (protein content is 20.9g/100g, fat content is 2g/100g), and the side dishes are enoki mushrooms, bamboo shoots, and kelp.

Image source: Boiled beef cooking package on e-commerce platform

If we convert it according to the protein content in the nutritional composition table, assuming that all the protein comes from beef, then the beef content should be about 33 grams per 100 grams, and the fat from beef can be almost ignored. That is to say, about 16 grams of cooking oil will be consumed in 100 grams of boiled beef dishes. The "Dietary Guidelines for Chinese Residents" recommends that the daily cooking oil should be controlled at 25-30 grams, and the average per meal is no more than 10 grams. If you often eat such high-fat pre-prepared dishes, it is easy to exceed the fat standard and increase the risk of obesity.

③Increase the risk of chronic diseases: Regular excessive fat intake in the diet will increase the risk of hyperlipidemia; excessive salt intake will increase the risk of hypertension.

Take the boiled beef above as an example. The sodium content is as high as 1110 mg/100 g, which is equivalent to 2.7 g of table salt. A box of boiled beef is 500 g, which is enough for 2-3 people. Even if each person eats 150 g, the salt intake is 4 g. The Dietary Guidelines for Chinese Residents recommends that the daily salt intake of each person should not exceed 5 g. If you eat 4 g in one meal, it is easy to exceed the salt limit throughout the day.

For example, the cooking package of preserved vegetables and pork in the picture below has a main ingredient content of about 96 grams. The sodium content is as high as 1021 mg/100 grams, which is equivalent to about 2.5 grams of salt per package, accounting for 50% of the recommended amount, which is not low.

Image source: Meicaikourou cooking package on e-commerce platform

In addition, iMedia Research analysts believe that most consumers are very receptive to pre-prepared meals, but prefer salty and spicy ones. Salty means high salt content, while spicy means high oil content. In other words, the pre-prepared meals that most people eat are high in oil and salt, which is not good for health if eaten for a long time.

If you want to eat, how to balance the nutrition?

Even though eating pre-prepared meals frequently may be bad for health, for office workers who are short on time, pre-prepared meals are indeed a necessity to fill their stomachs while working, and it is difficult to give them up. Moreover, even if you order takeout, you cannot escape the arrangement of pre-prepared meals. In this case, how can we strike a balance between "eating enough" and "nutrition"?

① Pay attention to the combination of meat and vegetables: When ordering, try to choose dishes with meat and vegetables, especially those with green leafy vegetables, or directly ask the merchant to order a portion of green leafy vegetables separately. If it is really not possible, order one meat and one vegetable and eat with colleagues. The merchant can stir-fry vegetables very quickly.

②Avoid cooking methods with high oil content: Try to avoid dishes such as stir-fried pork, boiled fish/meat slices, sweet and sour pork, and stir-fried beans, as these dishes are prone to oil and salt.

③ Bring your own vegetables and grains: For those who often order takeout, it is recommended to bring some convenient vegetables, such as lettuce, cucumber, cherry tomatoes, tomatoes, purple cabbage, and carrots, which can be eaten raw after washing. You can also bring roasted sweet potatoes, boiled corn, and oatmeal as part of the staple food to increase your intake of coarse grains.

④ Check the nutrition label: If you buy packaged preheated food, be sure to check the fat and sodium content on the nutrition label and choose foods with relatively low fat and sodium content. Limit the fat content to 10 grams and the sodium content to 800 milligrams per meal. Foods with a sodium content of ≥800 milligrams/100 grams are considered high-salt foods. [4]

Finally, we need to remind everyone that when ordering food, choose larger restaurants, and when purchasing packaged pre-prepared meals, choose regular large-brand merchants.

References

[1] iimedia Consulting https://www.iimedia.cn/c400/85944.html

[2] Wang Juan, Gao Qunyu, Lou Wenyong. Development status and trend of pre-prepared food industry in my country [J/OL]. Modern Food Science and Technology: 1-5 [2022-07-21]. DOI: 10.13982/j.mfst.1673-9078.2023.2.0388.

[3] Xiao Yang, Zhang Yueqi, Guo Beibei, Chen Haitao, Sun Baoguo, Zhang Yuyu. Comparison of volatile flavor components of fish-flavored pork shreds processed by two methods by SDE-GC-MS[J]. Food Science, 2015, 36(14): 70-75.

[4] Chinese Nutrition Society. Dietary Guidelines for Chinese Residents[M]. People's Medical Publishing House. 2022

Planning and production

This article is a work supported by Science Popularization China Starry Sky Project

Author | Xue Qingxin, member of Chinese Nutrition Society, registered dietitian, health manager, public nutritionist

Review | Han Hongwei, Director of Risk Communication Department, National Food Safety Risk Assessment Center

Produced by: China Association for Science and Technology, Science and Technology Press, Beijing Zhongke Xinghe Culture Media Co., Ltd.

Editor: Yinuo