Essentials: Healthy Eating & Eating Disorders - Anorexia, Bulimia, Binging

**Andrew Huberman** (0:00)
Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are going to talk all about healthy and disordered eating. And indeed, we are going to talk about clinical eating disorders, such as anorexia, bulimia and binge eating disorder, as well as some other related eating disorders. However, before we get into this material, I want to emphasize that today's discussion will include what it is to have a healthy relationship with food. We are going to talk about metabolism. We are going to talk about how eating frequency and what one eats influences things like appetite and satiety, as well as whether or not we have a healthy psychological relationship to food and our body weight and so-called body composition, the ratio of muscle to fat to bone, et cetera. So as we march into this conversation, I like to share with you some interesting and what I believe are important findings in the realm of nutrition and human behavior. I know these days many people are excited about or curious about so-called intermittent fasting. Intermittent fasting is, as the name implies, simply restricting one's feeding behavior, eating, to a particular phase of the 24 hour or so-called circadian cycle. Other forms of intermittent fasting involve not eating for extended periods of time, for entire days, or some people will extend to two days or three days, typically, and hopefully, they will drink water during those times, sometimes referred to as water fasting, which means that they are ingesting fluids, and hopefully, they are ingesting electrolytes, such as salt, potassium, and magnesium, as well, because while one can survive for some period of time without ingesting calories, it is extremely important to continue to ingest plenty of fluids and electrolytes. And the reason for that is that the neurons of your brain and body that control your movements, your thoughts, clarity of thinking in general, et cetera, is critically dependent on the presence of adequate levels of sodium, potassium, and magnesium, the electrolytes. And that's because neurons can only be electrically active by way of movement of particular ions, which include things like sodium, potassium, and magnesium. So without those, you can't think, you can't function, and it actually can be quite dangerous. So why all the excitement about intermittent fasting? Well, a lot of the excitement relates to work that was done by a former colleague of mine down at the Salk Institute for Biological Studies in San Diego named Sachin Panda. Sachin's lab identified some very important and impactful health benefits of restricting one's feeding window to particular times within the 24 hour cycle, or even to having extended fasts that go for a day or two days or maybe even three days. What they saw was an improvement in liver enzymes, an improvement in insulin sensitivity, which is something that is good. It means that you can utilize the calories and the blood and sugar that you happen to have. Being insulin insensitive is not good and is actually a form of diabetes. What Sachin's lab and subsequently other labs showed was that restricting one's feeding window to anywhere from four to eight or even 12 hours during each 24 hour cycle was beneficial in mice. And some studies in humans have also shown that it can be beneficial for various health parameters. However, the excitement about intermittent fasting seems to be related to the foundational truth about metabolism and weight loss and weight maintenance and weight gain, which is that regardless of whether or not you intermittent fast or whether or not you eat small meals all day long, or you eat one meal in the evening and snack up until then, it really doesn't matter in the sense that the calories that you ingest from whatever source are going to be filtered through the calories that you burn by way of exercise, basal metabolic rate, which is just the calories that you happen to burn, just being alive and thinking and breathing and your heart beating, et cetera. And the reason why many people prefer intermittent fasting to other forms of, let's just call it what it is, diet or nutritional framework is that many people find it easier to not eat than to limit their portion size. And here I'm not talking necessarily about eating disorders, I'm talking about the general population. So why are we talking about this? And in particular, why are we talking about this during an episode that includes a discussion about eating disorders? The reason is nobody, not the government, no nutritionists, no individual, no matter how knowledgeable they are about food and nutrition and food intake, can define the best plan for eating for any one individual. I'm going to repeat that. Nobody knows what truly healthy eating is. We only know the measurements we can take. Liver enzymes, blood lipid profiles, body weight, athletic performance, mental performance, whether or not you're cranky all day, whether or not you're feeling relaxed, nobody knows how to define these. And these have strong cultural and familial and socio-societal influence. So if you hang out with people that intermittent fast all day, that will seem normal. If you spend time with people that have never heard of intermittent fasting, intermittent fasting is going to seem very abnormal. Now we are going to talk about eating disorders that really fall into the category of clinically diagnosable eating disorders for which there's actually serious health hazards and even the serious risk of death. There are clear criteria in the psychiatric and psychological communities to define things like anorexia, bulimia, binge eating disorder, all of which we will talk about. But as we have that discussion, I want to emphasize that self-diagnosis can be both a terrific but also a very precarious thing. There's always a temptation, as one learns about the symptomology of a given disorder, it doesn't really matter what the disorder is, to ask the question, well, do I have that? Does so-and-so that I know have that? It's tempting to diagnose them and or ourselves as either having or not having a particular disorder.