These are some of the same questions I had. Maybe eating like this really does kill you but maybe it’s actually pointing at some other factors they didn’t even consider. Where did they find the study participants? Were they all overweight or obese and using IF to lose weight? Did they eat a healthy diet, or was it 8 hours a day of non-stop hamburgers and pizza? Did they exercise or were they physically active? It just sounds way too general to draw such dire conclusions. Again, maybe the time restriction is actually the problem but it doesn’t sound like there enough info here to actually determine that.