As far as I know there is no good data on "long covid" that substantially controls for confounders like obesity and age. Obese people are likely to have seemingly "long-term" effects from any respiratory problems that actually disappear if they lose weight (see for example obese asthma sufferers who often have what appears like chronic bronchitis). If you are aware of anything that provides evidence that accounts for confounders I'd be very happy to change my mind.