If she did even basic research on IF she'd know that besides obviously having the advantage of cutting your daily calories, it also (in theory) will make your body burn stored fat after you go 16 hours without eating. Not 1 hour.  not 2 hours.  16 hours.  It's pretty easy honestly I've been doing it for years now.  I usually go 20 hours.  Bed at 11pm and then don't eat until 7pm next day.