Lessons from the health policies for children during the pandemic in Japan

It is everyone's desire to seek the sound growth of children through food education and there is a critical need for fostering an environment for this purpose. Health policies are important for this support. To the present, the Japanese society has been greatly disrupted by COVID-19 pandemic. “Stay at home”, “mokusyoku (silent eating)”, and mask wearing were encouraged in nationwide campaigns as public health measures to combat COVID-19. There are some papers reporting negative effects of “stay at home” and lockdowns such as weight gain, decrease in physical activities and change in eating habits. In Japan, while benefits and advantages of food education during mealtime were previously well studied, the “mokusyoku” rule may directly run counter to this food education. Moreover, there are several reports showing that nutrients might contribute to prevention of infectious diseases. Japanese children were also encouraged to wear masks all day long. The results of the clinical research, especially randomized control trials, show limited protective effect of masks. On the other hand, negative outcomes of the masks were reported in various scenes. This review focuses on these topics and arousing reconsideration for a better environment for children.


Introduction
Eating, learning, and playful behaviors are essential for healthy development of children. Societies around the world, including Japan, have been severely affected by the COVID-19 pandemic. It was well announced that Japan had controlled the infection successfully without draconian lockdowns or other harsh restrictions which unduly limit private rights of citizens.
However, the environment in which children eat, learn and play has greatly been affected by health policies in Japan. While no proven effect of school closures against spread of COVID-19 has been reported (1), a few schools are still taking temporary closure measures (2). Though most schools were opened, children were strongly encouraged to follow the "mokusyoku" rule of eating lunch silently during the lunch time (3). Although the Ministry of Education, Culture, Sports, Science and Technology (MECSST) has modified the guideline of mask wearing in schools to Shobako .
/fpubh. . clarify that mask wearing is not necessary in physical education classes as long as the social distance (1-2 m) is maintained, the ministry still recommended to continue the mask wearing rule in schools (4). Typical events related to COVID-19 and children are summarized in Table 1. As shown, novel Coronavirus Response Headquarters present the basic policies for COVID-19 prevention, and each ministry announces relevant basic policies (5). MECSST presents guidelines describing the basic policy of countermeasures that the schools should take. Since most of them are only written recommendations, each municipality's board of education and school finally decide what kind of countermeasures to request for children. So, children were forced to comply with many kinds of measures. Examples of such measures are shown in Figure 1. As shown in the figure, children were forced to follow "The New Lifestyle (New Normal Lifestyle)" in the name of public health. An object of this paper is to summarize the findings about the result of health policies taken in Japan and looking back the challenges of science-based policy making.

"Stay at home" campaign
Draconian lockdowns were enforced in many regions in the world such as China and Europe to prevent the widespread of COVID-19. "Stay at home" campaign was also strongly promoted in Japan even though Japan did not adopt any lockdown with severe restrictions. During the campaign, while adults were not subject to commuting restrictions, children were forced to stay at home due to the long-term school closures. Some negative effects of the lockdowns and "Stay at home" campaign were previously reported. In Japan, during the state of emergency, schools were closed and a "stay-at home order" was issued. As a consequence, it was reported that children had higher body fat percentage, shorter single leg standing time, and a larger number of falls per month compared with children before the pandemic (6). Abe also reported that fundamental movement skills, especially for object control skills were impeded during this pandemic (7). In lowincome households, children's consumption of sweets, soft drinks, and ready-to-eat foods was increased (8). Horikawa et al. also reported children eating a balanced diet of meat or fish and vegetables at least twice a day decreased during the period (9). Horikawa's research also revealed the importance for the support of low-income households. Changes in eating habit was also observed in Kosaka's study and interfaced with feeling enervation and mental stress (10). Longer periods for video games were also reported in this study. Ueda et al. reported about half of children, participated in the research, experienced sleep pattern change during the period and its change was predicted by a high level of depression (11). In Nakachi et al. study, change tendency in sleep pattern was also observed in junior and high school students (12). Psychological problems were observed in lower grade of elementary school; they easily cried and complained, were unable to keep calm, and were dependent on parents and family members.
Similar results were reported outside Japan, where stronger behavioral restrictions have been imposed. For example, in China, significant increase in total food intake, especially snacks and drinks, and decrease in physical activities were reported (13). Negative effects of weight gain were also reported in research in U.S. (14,15). Changes in eating habits and lifestyle during lockdowns were also reported (16, 17). Increased risk in type 2 diabetes was also reported (18). The restrictive lifestyle and weight gain due to the lockdown are considered be the causes of the increased risk in type 2 diabetes. The survey conducted on children also showed a significant increase in the consumption of potato chips, red meat, and sugary drinks, and a significant decrease in time spent in sports (19). The studies presented in this section are summarized in Table 2A.

"Mokusyoku rule" and food education
The "Mokusyoku rule" is prohibition of conversation during meals in schools, working spaces, and restaurants (3,20). The novel Coronavirus Response Headquarters announced "mokusyoku" as a basic policy for COVID-19 prevention (5), and the Japanese government and industry groups are promoting this health policy by spreading awareness (21). As described in Section Introduction, the final decision relies on each municipality; some local governments relaxed the "mokusyoku rule" in schools, while others continue to instruct children to follow. In order to ensure the rule implementation, each school is trying to search for the best way, such as using partition or TV animation even in 2022 ( Figures 1C,D). In the early stage of the pandemic, droplet infection was thought highly threatening, and measures aimed at an assumed droplet pathogen were over-emphasized (22). The mokusyoku rule was thought to be a remnant of that time, the same as surrounding individuals with panels ( Figures 1C,E). There are no reports on the benefits of the "mokusyoku rule, " and several Japanese articles have expressed worry about or negatively commented on its impact on children (20).
The importance of conversations during meals for children has been well studied in Japan. Kishida and Kamimura reported conversation positive group (group with frequent conversation) gained higher scores for good appetite, not feeling fatigue, sleeping well, and not readily catching cold (23). There are also reports of positive effects on eating habits and reducing soft drink consumption. Esaki reported frequent conversation during meals has positive relation with meal-related quality of life (QOL) (24). Previous studies also showed that Japanese children who had conversations during meals had better dietary attitudes, eating behavior and mental QOLs (25)(26)(27). Surveys outside Japan have also reported that conversations  Year Month Typical event Topics with stay at home, mokusyoku, and masks 2020 January-March -A man who stayed in Wuhan tested positive for COVID-19 (first case in Japan).
-COVID-19 cases were confirmed among passengers aboard the Diamond Princess, which called at the port of Yokohama.
-School reopening guidelines in response to COVID-19 (school reopening guidelines) was announced.
-Prime Minister Shinzo Abe requested the simultaneous closure of all elementary and junior high schools nationwide.
-The Governor of Tokyo requested voluntary abstinence from going out.
-New Normal Lifestyle was presented by MHLW.
-Hygiene Management Manual at Schools (hygiene manual) ver.1 was announced.
-Simple school lunch was described as thoughtful for areas where infection is judged to be spreading.
-School reopening guidelines was updated. "In school education activities, please wear a mask regularly." was added. It was also stated that masks must be worn in situations where close-range conversations or vocalizations are required.
-The Governor of Tokyo announced "Stay home week." July-September -The "Go to travel campaign" started. -COVID-19 vaccination was started.
-About 7,000 children were reported to be voluntarily missing school due to fear of infection.
-A child died after an endurance run in school with a mask was placed on the chin.
-The Governor of Tokyo announced "Stay home week".
July-September -The 2020 Summer Olympics was held in Tokyo.
-The Governor of Tokyo called for "stay home" during summer vacation.
-There were requests for the extension of summer vacation due to fear of infection, and some schools responded.
-School closures, class closures were undertaken in Sapporo.
-Novel Coronavirus response headquarter (belongs to Japanese government) announced basic policy against for COVID-19 (basic policy) and "Mokusyoku" was set as the basis.
-The Governor of Tokyo called for "stay at home" hence the chairman of subcommittee on Novel Coronavirus Disease Control commented that it is not always necessary.
April-June -Latest guidelines for the school hygiene manual were updated (ver.8), a description about excessive sterilization was added.

TABLE (Continued)
Year

Month Typical event Topics with stay at home, mokusyoku, and masks
July-September -Expanded the fourth vaccination target (e.g., healthcare workers).
-Japan recorded the world's highest number of new COVID-19 infections.
-The MHLW homepage was updated about COVID-19 prevention. "Mokusyoku" is still the basis of the prevention response. In response to this, some boards of education and schools are encouraged to follow "mokusyoku" rule. On the other hand, some school boards have declared that they do not strongly recommend that.
Topics were taken from the homepage of the Japanese public broadcaster (https://www3.nhk.or.jp/news/special/coronavirus/chronology/), Tokyo metropolitan government (https://www.metro.tokyo.lg.jp/tosei/governor/governor/), the ministry of education, culture, sports, science and technology (https://www.mext.go.jp/ a_menu/coronavirus/index_00012.html), the ministry of Health, Labor and Welfare (https://corona.go.jp/emergency/). * A series of manners in which mask is removed with strings over the ears only when food is placed in the mouth and replaced immediately while chewing. This is sometimes seen in Japanese TV programs. However, it is now generally understood, as recommended by Kanagawa prefecture, that following the "mokusyoku" rule is more suitable during eating and wearing masks only when conversing (https://www.pref.kanagawa.jp/docs/r5k/mask_nisho.html). during meals in pre-kindergarten are effective for vocabulary acquisition because out-of-context conversations occur uniquely (28, 29). Although some papers suggest that people have indeed contracted COVID while eating in restaurants, such risk can be minimized by ventilation which is an important factor in preventing COVID (30, 31). As described above, conversations during meals are important for children to foster healthy minds and eating habits. Thus, it will be necessary to reconsider the "Mokusyoku rule" that would adversely affect physical and mental development and abolish the rule by taking measures Shobako . /fpubh. .
such as sufficient ventilation. Articles describing mokusyoku and food education are summarized in Table 2B. Some schools introduced "simple school lunch" with insufficient nutrition for fear of contact infection at the time of serving the meal ( Figure 1F). This has been described as thoughtful for areas where the infection is judged to be spreading, as per the first version of hygiene management manual at schools to the latest version, established by MECSST (4, 32). Tanaka  There was a significant increase in total food intake especially in snacks and soft drinks under "stay at home regulation". A significant decrease in physical activity was also observed. The rate of weight gain in the total population was 30.6%. The main factors contributing to weight gain were increased food intake and reduced physical activity.  Higher household income and education levels were significantly associated with higher rates of eating vegetables, using the information on nutrition labels, and conversing with family or friends during meals. Higher household incomes were also significantly associated with lower frequencies of family breakfasts in men and a lower frequency of family dinners.

Barnes et al. (28) and
Gest et al. (29) Food education 3-4 Children more prone to decontextualized talk, positing a key role for language learning during mealtime rather than free play and reading time.   days) of schools (33). The relationship between nutrients and infectious disease has been well studied (34). Vitamin D (VD) is probably the most well studied nutrient which has been reported to have a protective effect against COVID-19 infection (35). It is reported that serum 25-hydroxyvitamin D [25(OH)D] of <20 ng/mL is one of the risk factors of deficiency and according to a survey in South Korea, serum 25-hydroxyvitamin D [25(OH)D] of about the half of the 6-12 years old children was 20 ng/mL or less (36, 37). Not only from the diet, but also exposure to sunlight is important for vitamin D synthesis. During the pandemic, children's serum 25(OD)D concentration was significantly decreased. It was discussed that school closures and lockdowns were associated with this decrease (38). In the Turkey observational study for children under 18 years old, VD deficiency was significantly high in the COVID-19 patient group compared with the control group (39). Vitamin C (VC) and omega-3 fatty acids were also considered to prevent or reduce COVID-19 infection by cytokine modulation such as IL6, TNFα, and IL1β reduction and IL10 upregulation (40). Although some sufficient clinical observations have been reported, there are few data supporting active intervention especially for children (41). The situation of Vitamin E, considered as a natural killer cell and a T cell activator, was similar to VC (42). For children, there are a few RCTs showing positive effects of Vitamin A for preventing respiratory infections. However, the results of meta-analyses did not support active intervention (43). Zinc is well known for its important role for the development and maintenance of immune and other cells (44). Previous studies revealed that low zinc status is a risk factor of pneumonia infection for children (45). RCT studies for children also support the importance of Zinc (46). It was also reported that low selenium status is associated with COVID infection (47). Simple school lunch might be leading to opportunity loss of taking these nutrients. Horikawa et al. discussed that school lunches play an important role in continuing well-balanced eating habits (9). Detailed research about the nutrition of simple school lunches and their effect has not been performed, but Kojima reported that it might not provide necessary nutrients compared to regular school lunch, while there was an apparent effort in the areas where a state of emergency was declared for a long time (48).

Mask rules (mandate): Review of its e ectiveness
Wearing surgical masks was strongly recommended in Japan even for children in school, on the way to and from school, and even in the house (so called "family  (56) and demonstrated by Jacobs showed only significantly prolonged the duration of the headache (62) (Table 2C). Significant effectiveness of masks for COVID-19 prevention was reported in numerous observational studies (64-70) and "Bangladesh study" (71). Regarding the "Bangladesh study", there are some points to be noted in the interpretation of the results. First, the total sample size was too large to conduct proper evaluation (N = 342,183), and subgroup analysis revealed that no significant prevalence intervention ratio was observed in the age 50 subgroup for surgical mask. Second, increase of the physical distance was observed in mask group but not in the control group. Third, monetary reward was provided for participants. Chikina et al. recently reported the re-analysis results and pointed out potential biases that cannot be ignored (72). In support of this view, based on the results of meta-analysis of RCTs, the universal mask policy especially in community settings is not strongly recommended (73)(74)(75). While many observational studies reported on the effectiveness of face mask, Davies et al. pointed out that most of them were based on selfreporting, and <0.2% of studies studied the behavior in question objectively (76). Particularly, the frequency of hand washing tends to vary greatly between the actual and selfreported values, which might be the reason for overestimating mask-wearing effectiveness. Frequency of self-report mask use was also reported to differ from actual. Thus, we should carefully consider this when determining the effectiveness of personal protective equipment by observational studies. Given the sample size and results of RCTs, it may be necessary to reconsider overestimation of mask effectiveness for scientific integrity.
Effectiveness of the mask mandate should have been reconsidered as well. The survey in Europe and Texas state revealed that the mas mandate has no effect against COVID-19 infection, hospitalization, and mortality (77, 78). In Kansas, counties with mask mandate had significantly higher case fatality rates than counties without mask mandate, with a risk ratio of 1.85 for COVID-19-related deaths. The mechanism of this adverse effect is propounded as "Foegen effect" (79). This effect was supported by in vitro examinations. In the manikin model, favorable results of viral titer or viral RNA detection were observed when the receiver was not wearing a mask (80). It will be necessary to consider what happens if the simulation is continued for more than 20 min, extended from the experimented time. This paper also points out an important issue. The droplets captured by the mask might be transformed into aerosols and were floated in a chamber. Penetration and secondary atomization of droplets impacted on the surgical masks were also well studied (81,82). People wear masks for a long period of time and, it is considered that, due to the deposition of respiratory droplets released through multiple respiratory events, mask matrix becomes wet and secondary atomization of the droplets was promoted to produce aerosol. Contamination of the mask due to wearing for the prolonged period should also be considered. Park reported the result of culturing bacteria and fungi from outer and inner layers of the masks wore by 109 Japanese people, and it was found that the mean colony counts were 13.4-times higher on the face-side of masks (83). To sum up, the effectiveness of masks, especially universal masking, seems to be limited based on the evidence described above. Regarding this point, the effectiveness of mask rules in schools has not been proven as well. For example, upon comparison of two cities, it was found that recommendation of face mask use in schools for pupils aged 10-12 didn't lower the number of COVID-19 infections (84). Similar results were also reported in school settings in various countries such as Norway (85), U.K (86), and Spain (87).

Mask rules (mandate): Review of side e ects
Further, we should more deeply consider side effects of universal masking for children. Watanabe previously alerted mask addiction (88). Although wearing of masks makes it more difficult to read emotions and provides a temporary sense of security, the continued wearing of masks may diminish this sense of security, leading to a risk of worsening social anxiety.
Not only mental but also physical side effects of masks were well studied. Prolonged mask use is reported to cause headache and impaired cognition (89). Koseoglu et al. also reported increases in dyspnea, itching, ear pain, and headache induction (90). Ou et al. reported negative impact on the ventilation function of exercise with mask on in young healthy subjects (91). It is also important point that the weight of the surgical mask increased during the exercise (92). This means that masks were wet by evaporation of sweat. As described in the previous section, we should consider the accumulation of contaminated droplets for long periods and their release as aerosols. Children's modified Borgi score, an indicator of breath shortness, was significantly increased by the simple exercise with surgical mask compared to not wearing a mask (93).
Difficultly in recognition of emotion is also an important issue when considering universal masking for children. Ruba and Pollak reported aged 7-13 children have significant difficultly in reading emotion (94). In particular, mask inhibited

Discussion
Health policies during the COVID pandemic has changed our daily life especially in children in Japan. Children were encouraged to comply with "new way of life" which requires "stay at home", "mokusyoku", and wearing a mask all day long. This review summarized the scientific research related to these health policies.
First, I reviewed lockdown and "Stay at home" campaign. The relationship between COVID-19 and obesity in childhood was well reviewed (99). We should have to critically reflect on this health policy has caused changes in eating and exercise habits that increased obesity. The importance of nutritional education to prevent obesity is well studied (100). Dietary intervention programs to prevent body weight gain have also been developed (101). It will be important in the future to use these programs to develop health policies to prevent obesity during pandemic.
Second, I reviewed "mokusyoku rule" and food education and simple school lunch. Close contact is exactly risk factor of COVID infection (102) but for example, hand hygiene could reduce infection (103). In Japan, in-depth research has revealed the beneficial effects of food education and conversation during meals. Nutrients which are effective in preventing infectious diseases are also well studied. Health policies should be developed so that children can take enough these nutrients.
Third, I reviewed the mask rule. There was no mask obligation with penalties in Japan. However, mask wearing was strongly demanded. Over estimation of the effectiveness of mask might be impeding science-based health policy making and infection control. Psychological and physical adverse effect of prolonged mask wearing was also reviewed. As Thomson pointed out, any negative impact on mental or emotional wellbeing experienced by children who are required to wear masks may vary according to age and ability factors and which may yet be established, may be inconsistent with the WHO constitution (104). In the future, it will be necessary to proactively take less burdensome and less legally complex measures, such as adequate hand washing and ventilation.
Vaccination might have one of the key roles of the public health. The efficacy and safety of vaccination for children have been also well studied (105). However, the amount of spike protein synthesized in the body after vaccination has only been measured in adults and there is a discrepancy between the report of Ogata et al. which is in the picoorder (106), and the Cognetti and Miller in the micro-order (107). We should carefully consider the risk and benefits of vaccination and ensure that everyone's judgment is respected. In a recent survey, some parents (8.2%) answered that they intended to vaccinate their children because pediatricians might think less of them if they do not do so (108). This result might suggest that more thorough informed consent is needed. It is a matter of course that misleading media coverage focused only on the benefits or harms of vaccination should be refrained from, as such coverage only contributes to vaccine hesitancy.
As described in Section Introduction, Japan is a unique country that confronts the pandemic without measures with legal binding force, and administrative organs stayed with "recommendation" and avoided orders in most cases. It is reported that most Japanese people think "everyone should be responsible for their health" (109,110) and should refrain from outside recreation during the pandemic (111). They wear masks (112) and wash their hands (113) voluntarily because they value peer pressure and are afraid of being left out of the community. Television broadcasts, which repeatedly report excessively about facemasks, might also play a part in the formation of the public opinion that it is acceptable to condemn not wearing a mask. Before the pandemic, immoral post for social network service (SNS) by healthcare workers were sometimes came to an issue (114). In the pandemic period, there were not a few posts on SNS by healthcare workers denigrating those who do not want to wear masks and such opinion also might have an influence. Public opinion formed by the accumulation of these factors might influence, sometimes excessively, societal pandemic measures, including in schools.
Health policy should be developed based on multifaced scientific evidence and respect for individual values. Even if the measures have no legal binding force, sometimes measures with greater disadvantages, like those reviewed in this paper, are enforced, especially for children. It is important to regularly receive feedback from schools and review measures from multiple perspectives, including not only the opinion of public health experts but also experts in nutrition science, food education, psychology, and of course, children's opinion and rights.