Effect of obesity on Covid-19 outcomes
Various studies have shown a greater tendency for obese people to become severely ill with Covid-19, require hospitalisation or have an increased risk of death, compared with those not classed as obese (Sameer Mohammad, 2021). Inactive people also carry greater risks of severe Covid-19 outcomes. In one study, 84 out of 124 patients requiring mechanical ventilation had a Body Mass Index of over 30kg/m2. Obesity is known to increase vulnerability to other conditions and reduced immune response, which in turn increases the risk of serious outcomes for Covid-19.
It is therefore crucial at this time that exercise should be more widely encouraged, as part of an overall approach to reduce and manage obesity.
In a study of 2,839 people who tested positive for Covid-19, 44% required hospital admission 10 months after testing positive, showing signs of long-term complications or Long-Covid. Whilst this percentage is worryingly high, mildly obese patients were 28% more likely to develop such Long-Covid symptoms, whilst those with severe obesity were 30% more likely to develop long-term complications and sustained illness (Cleveland Clinic, 2021).
A study, which is yet to be peer reviewed, indicates that the Pfizer/BioNTech vaccine may be less effective in people classed as obese, with only half the antibodies produced compared with healthy people (Pellini, 2021). Excess body fat can cause metabolic changes such as insulin resistance and inflammation, which make it more difficult for the body to fight infection.
Ongoing low-level inflammation can weaken certain immune responses, including those launched by the B and T cells that trigger a protective response following vaccination. Separate research shows that the flu vaccine is only half as effective in obese people compared to those of healthy weight.