I'm pretty sure that eating less / intermittent fasting will help with Diabetes Type 2 (insulin resistance). Probably not with Type 1 though (inability to produce insulin), but that quite obviously isn't a healthy person.
A Diabetic is not healthy individual but the best part is Intermittent fasting and cold-showers are some of the few things that help with insulin and prevent diabetes.
[Merriam-Webster] Healthy: enjoying health and vigor of body, mind, or spirit
[Merriam-Webster] Health: the condition of being well or free from disease
[wikipedia] Diabetes mellitus (DM) also known as simply diabetes, is a group of metabolic diseases
You are not in good health / healthy in the manor meant in this thread and OA. You might eat healthy, exercise, whatever but you still suffer from a disease that healthy people do not.
Rejoice, you now know the same definition that nearly everyone else knows (rather than your far less useful personal make-believe definition). No longer will you have trouble communicating the state of your health or comprehension issues understanding other's. Bonus Cup! You are now less ignorant.
Also, note that he explicitly mentions that "A normal healthy adult should not have any problems when fasting for 24 hours."