Many studies have shown that obesity or severe overweight increase the mortality rate of patients with new crown. The University of London surveyed 300000 people, 640 of whom were hospitalized for the new crown. The study found that overweight and obese people were 40% and 70% more likely to be admitted to hospital than those with normal weight. The higher the body mass index (BMI), the more likely they were to be hospitalized. Underweight also increased the risk of severe illness, but only 6%. < / P > < p > obesity refers to the body state caused by excessive fat accumulation in the body. BMI is calculated as the weight (kg) divided by the square of height (m). Adults with BMI between 18.5 and 23.9 are considered as the standard, and those with BMI greater than 40 are considered as morbid obesity. < p > < p > Matthew B, a researcher at the University of Maryland, USA. Laurens pointed out that a number of long-term studies have shown that multiple vaccines are not as effective in obese adults as they are in non obese populations, including viral influenza and hepatitis B, as well as tetanus and rabies caused by other pathogenic organisms. According to Chris Xu, CEO of thermogenes, a biotech company, the website of Healthline cited higher body fat and leptin levels in obese people, which may hinder antibody production. Obesity may affect the activity of T cells, which play an important role in antibody production. In addition, obesity is actually a chronic mild systemic inflammation. Even if normal levels of antibodies are produced in the body, inflammation may affect the immune system’s response ability. < / P > < p > it has also been said that the conventional 1-inch needle used for immunization is not long enough, while the subcutaneous fat layer of obese people is thick, which makes the needle unable to reach the muscle under the fat layer, but the vaccine solution needs to stay in the muscle to achieve its best effect. ABC news pointed out that the only way to prove whether the new crown vaccine is effective for obese people is to include them in a large-scale phase III clinical trial. Previously, because of the chronic health status of obese people, drug trials usually did not include this group. The problem of obesity is related to personal living habits, socio-economic development and cultural background. Simply from the perspective of diet, protein, sugar and other nutrients long-term intake will be converted into fat. < / P > < p > for example, the UK is one of the fattest countries in Europe because of its love of a leisurely lifestyle and a high-fat diet such as fish and chips. According to the British government, 63% of adults in the country are overweight, with 2.9% of people suffering from morbid obesity, while 8% of new crown patients are morbidly obese. The Johnson administration has taken the lead in bringing obese people into the new high-risk group. Prime Minister Johnson plans to keep obese people in high-risk areas at home to prevent the second wave of outbreaks this autumn, the Sunday Telegraph reported. < / P > < p > the government also launched the “better health” program at the end of last month, which includes increasing bicycle lanes, banning junk food advertising after 9:00 p.m., and requiring restaurants to list the calories of dishes in their menus, in the hope of improving people’s health and better resisting the new coronavirus. < / P > < p > in order to encourage the British people to lose weight, the prime minister put himself forward and posted a video on twitter saying that he was seriously overweight when he was ill. Johnson confirmed the novel coronavirus pneumonia at the end of March this year, and then entered ICU. He made up his mind to lose weight after he left the hospital. Johnson, who was nearly 1.8 meters tall, weighed 222 Jin and had a BMI of 35. If you can lose a little weight, you can not only protect your health, but also reduce the pressure on the NHS, Johnson said. The Johnson administration hopes that the program will encourage overweight people to lose about 2.5kg and save the NHS 105 million pounds over the next five years. However, wera Hobhouse, a British liberal Councillor, believes that obesity is a structural problem of British society, which is more related to family expenditure budget. Poor families do not have the right to choose a healthy diet. In an article published on July 15 in the New England Journal of medicine, it was also pointed out that obesity and obesity related diseases, such as hypertension, diabetes and cardiovascular disease, had a negative impact on the new crown epidemic, which was also a kind of health inequality. It is pointed out in the article that unhealthy eating habits have always been one of the most important lethal factors in American society, even surpassing smoking. A healthy diet should be a high proportion of fruits and vegetables, and a low proportion of processed foods with high sugar and high calories. However, it also depends on the external conditions such as family economic status, living environment and educational background. < / P > < p > another survey in Ethiopia also found that when household food consumption decreased, the most reduced categories were also the most nutritious foods, such as fruits, meat, eggs and dairy products. The decline in income will force many poor families to turn to more starchy staple food to satisfy their hunger, reduce dietary diversity and increase health risks. < / P > < p > according to the data released by the US Department of agriculture in 2018, 11.1% of American households are still in a state of food insecurity, most of which are ethnic minority families. These families in a vulnerable position tend to choose processed food with low price and less nutrients, which eventually leads to high obesity rate. According to the data of the Centers for Disease Control and prevention of the United States, the proportion of obese adults in the United States is 42.4%, but that of black people and indigenous people is 49.6% and 48.1%. Correspondingly, the novel coronavirus pneumonia rates of the two groups were nearly 5 times higher than that of the white population.