Reading these two rules to try and relate them to one’s own situation sometimes confuses me. I am a diabetic in my sixties. My interpretation is that I am excused from fasting by way of age and health (volume reduction) but not from abstinence (no flesh meat).
Additionally, sometimes it’s difficult for a diabetic to time a meal or snack to comply with the one hour rule prior to communion. I follow the fasting rule but I’m sometimes compelled (to avoid diabetic hypoglycemia) to eat more than I really need just before the one hour limit. A snack just before mass could build a bridge until after mass for a diabetic to avoid a glucose low. I’m not sure I’m allowed to break the rule prior to communion so I just “load up” 65 minutes before mass.