In this insightful discussion, Dr. Jason Fung, a nephrologist and pioneer of intermittent fasting, challenges the conventional 'calories in, calories out' model of weight loss, emphasizing the pivotal role hormones play in obesity and type 2 diabetes. He argues that frequent eating and processed carbohydrates spike insulin, driving energy into storage and leaving individuals perpetually hungry. Fung advocates for intermittent fasting and dietary changes as effective, accessible tools for reducing insulin levels, activating fat burning, and potentially reversing type 2 diabetes, shifting the focus from calorie counting to understanding the hormonal impact of food and the importance of fasting periods. He also touches on the evolutionary advantages of fasting, the regenerative process of autophagy, and the societal stigma surrounding obesity, urging a deeper exploration of eating patterns and their physiological effects.
"This calories in, calories out model doesn't work at all if you're trying to lose weight."
This quote emphasizes the ineffectiveness of the traditional approach to weight loss that focuses on calorie counting.
"It's about fixing the hormones that are behind the calories."
Dr. Fung's quote highlights the need to address hormonal imbalances to effectively manage weight.
"The whole point was how to get people to lose weight."
The quote reflects Dr. Fung's motivation for writing the book, focusing on effective weight loss strategies.
"If you eat an egg, you don't get that spike in insulin."
Dr. Fung explains that certain foods do not lead to rapid insulin increases, which can help control hunger and manage weight.
"If you gain too much body fat, your fat cells, for example, will produce leptin, which is another hormone."
This quote explains how the body uses hormones like leptin to regulate food intake and maintain a healthy weight.
"The problem is likely not an individual willpower problem. The problem is likely that there's something wrong with the message we're giving people."
Dr. Fung argues that the widespread issue of obesity is not due to a lack of willpower but rather to the flawed dietary advice and food environment.
"Insulin is pushing us to gain weight. Leptin is pushing us to lose weight."
The quote explains the balance between insulin and leptin in regulating body weight.
"About 70% of your risk of becoming obese is due to genetics."
Dr. Fung acknowledges the genetic influence on obesity but suggests that other factors have driven the recent increase in obesity rates.
"So every continent is seeing this increase in obesity. Therefore, this recent change within the last 50 years is not due to a change in Genetics."
This quote highlights the global nature of the obesity epidemic and dismisses genetics as the primary cause for the recent increase in obesity rates.
"So, while, yes, it's true that there is a strong genetic component that explains my risk of, say, obesity compared to yours, but doesn't explain how the population of the United States, for example, all of a sudden became much more obese in general."
Dr. Jason Fung emphasizes that while genetics may explain individual differences in obesity risk, it does not account for the widespread increase in obesity across populations.
"It's unquestionably false because every single study that we've done over the last 50 years shows that if you eat 500 fewer calories, then over time, depending on what foods you're eating, eventually your body will just burn 500 fewer calories."
Dr. Jason Fung refutes the notion that a simple reduction in calories leads to weight loss, explaining that the body adapts by reducing its energy expenditure.
"So that's that yoyo dieting effect. So say you start with 2000 calories. In, 2000 calories out, you're not gaining weight, you're not losing weight. Right? Now you decide, okay, I'm going to go on a diet. [...] Your metabolic rate has just now gone down by 500 calories. And guess what? You're not losing any body fat."
This quote describes the process of yoyo dieting, where caloric restriction leads to a lower metabolic rate, which can cause weight gain once the diet ends.
"Food contains calories, energy, but it contains instructions as well as to what to do. [...] It's the hormonal signal that says, please take energy out, open up the doors so that body fat can come out."
Dr. Jason Fung explains that food provides both energy and hormonal instructions to the body, with intermittent fasting serving as a tool to regulate these signals for weight loss.
"It's very hard to exercise enough to lose weight. And that's not to say that you shouldn't exercise. You really should exercise. Everybody should exercise. But if you're trying to lose weight, you still got to focus on the main topic, which is the foods that you eat."
Dr. Jason Fung acknowledges the benefits of exercise but stresses that for weight loss, dietary choices and their hormonal consequences are more critical than exercise alone.
"In 1977, we told people, eat lots of carbs, okay? [...] But what happened is that as we started to eat sort of a lot of carbs, what happened is exactly as what we discussed before. You eat two slices of bread in the morning with jam, you have no satiety."
Dr. Jason Fung discusses the shift in dietary advice and eating habits since 1977, leading to increased snacking and associated weight gain due to poor satiety and high insulin levels.
"You because in 2013, 2014, really, nobody was talking about it from a medical standpoint. [...] And really, I was for years, sort of this one voice in the wilderness that was saying, like, hey, this is a tool for us."
Stephen acknowledges Dr. Jason Fung's role in bringing intermittent fasting to the forefront of weight loss strategies, highlighting his early advocacy despite professional skepticism.
"Your body's activating itself during fasting, which is fascinating, because if you're trying to lose weight, dropping that basal metabolic rate is death."
This quote emphasizes the counterintuitive finding that fasting can activate the body's metabolism, which is advantageous for weight loss efforts.
"When you don't eat, what happens in your body from a hormone standpoint is that your insulin is going to fall. You're going to allow your body to start using the calories that are in the body. At the same time, other hormones go up, so the sympathetic tone goes up, which is your fight or flight response. Your cortisol levels go up, because, again, it's an activation. And your growth hormone goes up because those hormones are going to start telling your body to start pulling calories out."
Dr. Fung explains the physiological response to fasting, where a decrease in insulin and an increase in other hormones leads to the body using its stored calories.
"The whole idea that you need to eat as soon as you get up is just false."
Dr. Fung argues against the common belief that breakfast is a mandatory meal to start the day.
"The more often you eat, in general, the more calories you take in."
This quote highlights the relationship between meal frequency and caloric intake, suggesting that less frequent eating may lead to consuming fewer calories.
"There's no rules for fasting. It could be 16 hours. So 14 hours, remember, is sort of a baseline."
Dr. Fung explains that fasting can vary in duration, and there is flexibility in how it can be practiced.
"If you have all those calories sitting on your body, right? 100,000 calories sitting in body fat and you don't eat for three days. Well, you need 6000 calories. Well, you have 100,000, 200,000. So what's the problem? Take it out of your body fat."
This quote clarifies the logic behind fasting, where the body is expected to draw from its fat reserves during periods without food.
"It's about controlling your hunger. It's about that one level deeper. Why are you taking so many calories? So if you simply reduce the hunger, you're going to naturally eat fewer calories, which is going to cause weight loss."
Dr. Fung emphasizes that managing hunger through hormonal regulation is key to reducing caloric intake and achieving weight loss.
"Every successful drug to gain or lose weight, right, is a hormone. It's a hormone based, because that's instructions to the body."
This quote underlines the significance of hormones as the primary drivers of bodily functions, including weight management.
"Taking out fiber is a great way to make foods more appealing, if you will."
Dr. Fung discusses how the removal of fiber during food processing can make foods more palatable but less beneficial for health.
"If you have a lot of fiber, it acts almost sort of like an antidote to that carbohydrate because you're slowing down that release."
This quote highlights the role of fiber in moderating the body's insulin response and mitigating the negative effects of carbohydrates.
"Protein is not a way for the body to store energy. So when you're eating a lot of protein, it's very difficult for it to turn it into a storage mechanism."
Dr. Fung explains that the body does not store protein as energy, making it a less significant factor in weight gain compared to carbohydrates and fat.
"Fasting is certainly one way, but just changing the foods to other ones, because if you look at the insulin release in processed foods versus unprocessed foods, there's a huge difference."
This quote suggests that in addition to fasting, choosing less processed foods can also positively influence insulin levels and overall health.
"Well, autophagy might be that way to break down some of the stuff that you actually can't break down any other way."
This quote explains the concept of autophagy as a unique process for breaking down cellular waste, which cannot be eliminated through other means.
"So what it does is says, okay, well, I'm going to give you more energy, so I'm going to activate the body, but then I'm going to change where you're getting your energy from."
Dr. Jason Fung describes how the body adapts during fasting by shifting energy sources from external food to internal fat stores, an evolutionary mechanism for survival.
"This product, called Daily Greens, is one of the most highly requested products at Huel, but it's never been sold in the UK before until now."
Stephen shares the news about the availability of a popular Huel product in the UK market, highlighting its demand.
"But the most interesting thing, I think, is in the field of type two diabetes, because it's such an important disease."
Dr. Jason Fung emphasizes the significance of type 2 diabetes as a major health issue and the promising results of reversing it through dietary changes.
"I'm not talking about a drug that costs thousands of dollars. I'm not talking about a surgery which is only available to the 1%. I'm talking about a treatment which is intermittent fasting, which is available to everybody in the entire world for free."
This quote highlights the accessibility and cost-effectiveness of intermittent fasting as a treatment for type 2 diabetes compared to conventional medical interventions.
"They're just very slow to say, hey, this makes a lot of sense, because for them, they've invested so much in this calories in, calories out model."
Dr. Jason Fung points out the reluctance of the medical community to accept new ideas that challenge long-held beliefs on weight management.
"It's a fad diet. Well, it's been around for 2000 plus years. That's a long, long, long fad."
This quote from Dr. Jason Fung counters the argument that intermittent fasting is a temporary trend by referencing its historical and widespread practice.
"It's correct. But it's sort of not getting to that root deeper cause that we need to in order to help people, and that's causing us to blame them."
Dr. Jason Fung criticizes the calories in, calories out model for being superficial and leading to victim-blaming in the context of obesity.
"If you look at a lot of religions, for example, it's like, oh, they were so far ahead of us. What did they do? They brought people together every week."
This quote connects the importance of community and shared practices like fasting to health and happiness, suggesting that modern society could learn from historical and religious models.
"I really hope that my work helps people sort of reverse the type two diabetes, because that is really sort of one of the most close things that I deal with."
Dr. Jason Fung expresses his aspiration to make a significant impact on the treatment and perception of type 2 diabetes through his work.
"I'm trying to tell them about something that everybody in human history has been exposed to, which is intermittent fasting."
This quote by Dr. Jason Fung underscores his goal to reintroduce the concept of intermittent fasting as a natural and historically prevalent health practice.