Jason Fung, M.D.: Fasting as a potent antidote to obesity, insulin resistance, type 2 diabetes, and the many symptoms of metabolic illness

If you ever look back and say 'Hey, where did we get this idea that we should eat six or eight times a day?' From nowhere. Somebody made it up, it stuck, and that was about it.

I think the biggest benefit of time-restricted feeding is the psychological one ... People think intravenous access to food is essential for life. If they go more than two hours without a meal, the sky is gonna fall. So, in many ways, time-restricted feeding is just a way to prove to them that is total nonsense.

Testosterone is very anabolic to muscle, which insulin is as well, but testosterone is catabolic to fat, whereas insulin is anabolic to fat and anabolic to muscle. Cortisol, just to bring it full circle, is the worst of both worlds—hypercortisolemia is catabolic to muscle while anabolic to fat.

Hyperinsulinemia (too much insulin) is really what is behind abdominal obesity, high blood glucose, high blood pressure, low HDL, and hypertriglyceridemia. That's the metabolic syndrome.

We know that cortisol has a huge impact on body fatness ... If you get good sleep, you're more likely to be at a good weight. If you are sleep-deprived, for example, it's a stressful situation where cortisol is going to go up, then you're more likely to gain weight.

There's no more potent way to lower insulin than to fast.

You have three nutrients sensors: You have insulin, you have mTOR, and you have AMPK ... Insulin responds to dietary carbohydrates and dietary proteins. mTOR responds mostly to dietary proteins. AMPK actually measures the AMP to ATP ratio, so it actually doesn't care about what you eat; it just cares about the cellular energy availability.

Dr. Peter Attia recommend patients supplement with phosphatidylserine and GABA to aid sleep during a prolonged fast.

Fasting is what I call medical bariatrics. You get all the benefits of bariatric surgery without doing any surgery.

We see this all the time... As you prescribe insulin, people gain weight. You give sulfonylureas, which increase insulin, then people gain weight. You give them SGLT2s, which make insulin drop, then you lose weight.

That, to me, is one of the big problems with insulin.... You're telling your body to grow all the time when it really shouldn't be growing all the time.

I'm generally suspect of people who have very, very strong points of view on things in biology or medicine who no longer interact with patients.

Insulin has actually many, many different functions—only one of which is letting glucose into the cell.

Obesity itself is actually a protective mechanism against hyperinsulinemia and too much sugar.

I think it's more likely that the hyperinsulinemia is driving the obesity rather than the other way around.

In 2019, I think that there is no more promising agent than rapamycin for longevity.