Hey, we're not Doctors. We're just a regular family collecting information on the Internet.
Every risk I've seen attributed to fasting seems to be related to poor management: Dehydration, stress, poor sleep, depleted electrolytes, going right back to poor habits when the fast is over.
Of course, this doesn’t include some of the crazy things I’ve read out there that contradicts the actual science. "It will slow down your metabolism!", it doesn’t. "After 3 days, your body eats your organ linings!". Not even remotely true.
Seriously. If you are fat, your body is actually covered in food. Food you need to eat. The world record holder for a therapeutic fast was a fellow from Scotland who fasted for 382 days. He weighed in at 456 pounds, fasted to 180 pounds, and 5 years later weighed 196 pounds.