It seems more Americans than ever have food allergies these days, especially kids. However, a recent report by the National Academies of Sciences, Engineering, and Medicine says questions persist about whether food allergies are really on the rise. For example, the report cites a lot of confusion about what's truly a potentially life-threatening "allergy," which is triggered by the immune system, and what might be an intolerance or a sensitivity, triggered by the digestive system, instead.