Generally speaking, an obesogenic diet, so the worst thing you can do is have a diet high in a lot of fats, particularly saturated fat, combined with refined sugar. So think like ice cream, right? Anything that's really high in saturated fat plus refined sugar can cause intestinal permeability. Obesity itself can play a role in that as well. Binge drinking is another one. Chronic stress ... Releasing stress hormones causes intestinal permeability...