In the past months, many of us have had to stay home, work from home, and organize social events online, from home. This has led to a great reduction in physical activity, which has negative effects on both our physical and mental health. Moving less can result in gaining weight, and this is especially worrying for people who already have obesity. What’s worse, having obesity is a risk factor for being hospitalized after an infection of the SARS-CoV-2 virus, which causes the COVID-19 pandemic. It is therefore important that people keep exercising, in addition to following a healthy diet, in order to stay healthy, both physically and mentally. In the last decade, we have seen exponential growth in the prevalence of obesity and related chronic diseases, which affect both sexes equally. Although some studies or government policies consider it a problem in developed countries, the latest data on obesity reach global levels according to recent work . Since dietary patterns differ across countries, we can compare differences in dietary composition (i.e., the average amounts of macro and micronutrients consumed (the energy value of foods that are frequently consumed), and consumption patterns (i.e. meal frequency) with the infection rate and virality detected in relation to the SARS-CoV-2 crisis situation. Studying these differences can give an idea of the beneficial and detrimental effects in relation to diet and lifestyle.
The increased prevalence of obesity has gone hand in hand with the radical changes in our lifestyle. We use more motorized vehicles to travel and we have increasingly sedentary jobs, that generate anxiety and stress, as well as increasing hours of work. All these factors decrease the time spent on exercising or physical activity. And they increase the consumption of processed or ready-made foods. Int the last few months, many of us have had to work from home as a result of the COVID-19 epidemic . As a sedentary lifestyle reduces our body’s energy consumption, we need to consume less food, or otherwise, we gain weight. But inactivity and a sedentary lifestyle are not only associated with obesity, they are also risk factors for SARS-CoV-2 infection . In patients who are obese and overweight, there is a greater predisposition to the severity that the viral infection can reach. According to the recently published study by Klang E et al., hospitalized patients under 50 years of age with severe obesity are more likely to die of Covid-19 . Among the main characteristics associated with obesity are hormonal values that differ from those of patients with normal weight, and a flawed response of the immune system.
Exercise and physical activity are great ways to maintain a healthy balance between ingested foods and the energy consumed that allows one to maintain an adequate weight. Regular exercise or physical activity is also beneficial for our immune system, reduces inflammation
[4, 5], and reduces cognitive decline . Even mild to moderate physical exercise can boost our immune system and hence is one of the main strategies for dealing with the Covid-19 pandemic crisis .
Physical activity has also been associated with psychological effects [2, 6] Psychological stress in confinement situations (such as having to stay at home) causes hormonal changes that, in turn, affect the immune system. This can result in other negative psychological effects, such as symptoms of post-traumatic stress, confusion, and anger. Even short 10-day confinements can reduce the expression of immune cells such as lymphocytes and natural killer cells that are important to combat the virus. After longer periods of confinement, we see the reverse, with the number of white blood cells and other immune cells rapidly increasing. Disruption in the immune system is linked to health risks and increased levels of stress depression, and
Exercise and health professionals, local authorities and governments, therefore, should encourage the promotion of exercise either inside people’s homes or outside (of course, respecting the distances marked by the authorities and in safe conditions) . Regularly having mild-moderate physical exercise and maintaining an average state of activity will allow addressing the health crisis through obesity prevention and the reinforcement of the immune system. Of course, following a healthy dietary pattern is essential, but it must be accompanied by physical activity to stay healthy . The PREDIMED-PLUS study is one of the key studies in this regard since it investigates both the effects of the Mediterranean diet and exercise intervention, in both people with cardiovascular risk factors  and a general population . After a 1-year follow-up, participants showed improvements in nutrient density for all micronutrients assessed. The density of carbohydrates (− 9.0%), saturated fatty acids (− 10.4%), and total energy intake (− 6.3%) decreased. These changes were more pronounced in the subset of participants with higher improvements in MedDiet adherence. These are good reasons to follow this dies even in lockdown periods.