Is Corona Virus more deadly for obese people?
Coronavirus: How does obesity or obesity affect human illness?
Obesity is known to increase the risk of many diseases, including heart disease, cancer and type 2 diabetes.
Early studies suggest that it may also make people more sick with Covid-19, but why is that?
Is there any evidence of obesity that could be harmful to the virus?
This question has been the subject of many studies as experts try to find the answer.
In a study done by nearly 17,000 patients with Covid-19 hospitals in the UK, those who were obese - with a body mass index (BMI) of over 30 people - had a higher risk of death than those who were not very large.
A separate study of NHS health records found double the risk of Covid-19 deaths among obese people. If other health conditions linked to obesity such as heart disease and type 2 diabetes can also be taken into account the risk can be very high, investigators said.
And a study of critically ill patients in the UK taking care of the worst patients found that about 34.5% were obese, 31.5% fat and 7% morbidly obese (73% total), compared to 26% have a healthy BMI.
These figures are compared with 64% obese and obese people in the UK - 35% with a BMI of 25-29 and 29% with a BMI of 30 or more.
The mass index is calculated as the weight of a person in pounds divided by their height in square meters.
Given the world's highest obesity rates, the World Obesity Federation says a high percentage of people contracting "will also have a BMI greater than 25". Early studies from the US, Italy and China also show that this is an important risk factor.
Aging, manhood and underlying health problems all increase the risk of serious illness from Covid-19.
Why is obesity dangerous?
The more obese you are, the more fat you have, the more weight you need and the lower your lung capacity. This means that it is a big struggle to get oxygen in the blood and around the body. This affects the heart and blood circulation too.
"Ultimately, most of the body is frustrated by the lack of oxygen in the major organs," said Dr Dyan Sellayah, of the University of Education.
This is one of the reasons why obese and overweight people in several care require respiratory assistance and kidney function support.
What role do fat cells play?
Scientists have discovered that an enzyme called ACE2, which is present in the cells, is the main way for the virus to enter the body.
Higher levels of this molecule are thought to be found in adipose tissue, or fatty tissue, in obese people who have more - under the skin and in their genital organs.
That could be one reason why they have a higher risk of contracting the disease and a higher risk of getting sick with it.
Are the immune system also affected?
Above all else, the immune system - known as the immune reaction - is less effective for obese people.
That is due to inflammation driven by macrophage cells that invade our fat tissue. They interfere with how our cells respond to infection.
According to scientists, this could lead to a 'cytokine storm' - a life-threatening condition over which the immune system causes inflammation and serious injury.
Certain types of fat tissue tend to be attacked by macrophages. This could explain why people from black, black and minority ethnic backgrounds (BAME), who have this type of tissue, "raise their blood sugar levels, and may be at higher risk of the disease," Dr Sellayah said.
Can there be any other hidden problems?
Obesity often comes with other health issues, such as heart or lung failure, poor kidney function or type 2 diabetes.