Eating less calories will not make you lose weight, if your hormones are off. Fasting helps regulate the root ie hormonal in balance. He is a Dr, so props to his experience. But he is taking a very complex issue and throwing it into 4 minutes. It's not "complete" and won't help most folks, as stated so simply.
Insulin resistance does not occur from not eating, it's more likely from intense "repetitive" signal information (hormones) from eating certain types of carbohydrates and poor proteins, consistently.
Excercise is great for the body, but that too will do very little to lose weight, if the hormones an base level nutrient intake are not taken care of FIRST. If it's about science and math, the effort to burn a single calorie, will never match daily intake, plus any additional stored excess fat.