Food delivery is now an "essential" for more people than it ever was before. Doordash/Uber Eats is how a weirdly large amount of people eat in general.
The rate of increase in childhood obesity went up during covid.
You realize that is far too recent to show up in cancer death rates for under-40 year olds right? It takes 10-15 years for a change-in-behavior to show up in incidence and even longer for deaths. As a classic example, see the shift (i.e. the delay) in curve of reduced smoking and reduced lung cancer.