The Diary Of A CEO with Steven Bartlett - Most Replayed Moment: Is Milk Healthy? The Truth About Dairy, Sugar, Fruit And Fasting

Episode Date: June 12, 2026

Dr Mark Hyman is a physician and bestselling author specialising in food, longevity and metabolic health. In this moment, he reveals why willpower fails around food, what the science says about dairy and milk, whether fruit is actually good for us, and how the timing of your meals could affect your health and ageing. Listen to the full episode here! Spotify: https://g2ul0.app.link/U6SytX86w3b Apple: https://g2ul0.app.link/v3YPvgd7w3b Watch the Episodes On YouTube: ⁠⁠https://www.youtube.com/c/%20TheDiaryOfACEO/videos Dr Mark Hyman: https://drhyman.com/

I got told the other day, which helped me understand myself, I got told that when we're hungry, especially when it's sort of late at night, the logical center of our brain, like the prefrontal cortex, is less active, and the amygdala, the sort of emotional part of our brain that wants the dopamine, it's much more active. And it helped me to understand why,

maybe late at night, if I haven't planned my food, I'm much more susceptible to make a bad food choice that I then regret. I'm much more acceptable to lean in for sugar or something that's like super high in carbs or whatever. That really helped me. And this is why the planning thing makes a lot of sense because I can use my prefrontal cortex,

my logic sense of my brain, to make the food choice in the morning. Yeah. So that I don't find myself making a mistake. It's so important, Stephen, because people have to understand that willpower is not the answer. You cannot use willpower to control your food behavior.

It's part of your ancestral, evolutionary, limbic, reptile, dinosaur, our brain. And so when your blood sugar drops, you're going to eat whatever in front of you. There's a vending machine, if there's a donut, if it's cookies, it doesn't matter. Even if you know better, and I've experienced this, you're just going to eat whatever because it's a life-threatening emergency. Your body doesn't know that there's grocery stores and restaurants. It means you're going to go out and try to hunt and gather and do something. It's like an emergency. So when you have that food emergency and you don't have the right food on you, you're in trouble. I have that all the time.

I have this constant fight with myself where this one voice is like, do the fucking right thing. And then this other part of my brain is like, just today, break the rule. But obviously that voice is louder sometimes than others. And typically late at night, it's louder. Yeah, sleep deprivation. Stress. Stress. Sleep deprivation, all that increases your appetite, increases cortisol.

It increases grailin, which is a hunger hormone. You know, you can take young, healthy college kids and sleep deprivation. pride of them and they're going to crave carbs, they're going to crave sugar, and they're going to gain weight. It's not rocket science. What about for someone that doesn't have any money at all, it's so they can't, you know, they don't have the ability to, a lot of the privileges that me and you have, what are some of the very basics that they should be thinking about in order to remain healthy in a world where every convenience store is trying to sell you something cheap and sugary? Yeah, so a really good question. You know, I think, I think the economics of being

healthy is a problem. And we know that there's a huge disparity in health. But it's not only economic, it's education. You know, I met with a woman who was the doctorate, a clinic in Bed-Stuyvesant, which is in Brooklyn, it's a very underserved area. And in a very low-sociconomic status group, very unhealthy. And she said, you know, Mark, did you know the number one predictor of health? Is it money? Nope. It's education. So even people who are wealthy, but haven't been educated, still have issues. So for me, it was really about education. And so people can be educated to do the right thing, and it doesn't have to be expensive.

And I was part of this film 10 years ago called Fed Up that looked at childed obesity in our food system and the advent of sugar and marketing and processed foods. And we visit a lot of families. And I work with a family in South Carolina and Easley. It's one of the poorest areas in America. and it has the worst, call it the food deserts, one of the worst food deserts in America, basically where there's not a lot of healthy options to choose from.

And there's something called the Retail Food Environment Index. How many healthy grocery stores are there to fast food and convenience stores? And there was like 10 to 1. It was terrible. And his family, you know, lived on $1,000 a month for food, for family of five. They lived in a trailer.

They were in disability and food stamps. the mother was 100 plus pounds overweight, the father was very overweight, had type 2 diabetes, and it was already at 42-year-olds old, was on dialysis for kidney failure, which is amazing, because you usually don't see that until later,

that the son was 16 years old and 50% body fat, guys should be 10 to 20, and it was about, to be diabetic, was pre-diabetic. And rather than kind of, they were part of the movie, I said, why do you want to do this?

They were like, well, in order for my dad to get the kidney transplant, he asked, she was a weight, we're trying, we don't know what to do. We're doing all this low-fat stuff, and we're doing all these diet stuff we have in the house, not working. So I went to their house, their trailer, and rather than giving me a lecture about what to do, I said, let's cook a meal together. But first, let's do an inspection of your kitchen, and let's see what's in here.

And so we pulled out everything from the freezer and the fridge and the cupboards, and everything was packaged, box, processed. Everything was very high and high-fructose corn syrup from the peanut butter to the salad dressing. Everything had trans fat in it, which is deadly. and a lot of it said diet this. And my basic rule is if it has a health claim on the label, don't eat it. You know, it's gluten-free potato chips. It doesn't make it healthy, right?

Coca-Cola is gluten-free. It doesn't make it healthy. So I showed them what they were doing. And I said, let's just make a simple meal. Here's a guide called Good Food on a Tight Budget. How do eat well for you, for the planet, and your wallet. And it's made by the Environmental Working Group. You can get up on eWG.org.

It's free. and it was like how do you choose the cheaper cuts of meat or the beans or the grains or the veggies you know like onions and carrots and celery are not expensive you know like a lot of veggies are expensive so we made turkey chili we made a salad from fresh ingredients olive oil and vinegar dressing not dressing that was full of chemicals and high fructose corn syrup and refined oils we i showed them how to roast sweet potatoes i showed them how to stir fry vegetables we had some asparagus They never eaten anything fresh. They never cooked in the kitchen.

And the kids came out or playing video games. They came running in the kitchen. Like, what's that smell? Like there was like the roasting of the sweet potatoes. We had this beautiful dinner together. They love the food. And I was like, you know what? I don't know if it's going to work, but you don't, they didn't even have cutting boards.

They didn't have knives. Like they literally hadn't, like we tried to cut the, you know, the onions and the sweet potatoes with a butter knife because that's all they had. It was like a butter knife. It was really hard. So I bought them on the way. home, I bought them cutting boards on Amazon and on eyes, and I sent it to their house. Next week, the mom text me, she says, Mark, we lost 18 pounds this week as a family.

A year later, the father lost 45, got a new kidney. The mother lost 100 pounds. The son lost 132 pounds and went to medical school. The first guy in his family had gone to college, and he asked me for a letter of recommendation for medical school. And they lived in one of the worst food deserts. They didn't have much, you know, economically, and they were able to figure it out. because eating real food doesn't have to be expensive.

You don't have to have a $70 wago ribeye steak, right? You can eat real food. And it's just as simple as not eating the ultra-processed food. It's so bad for us, and it kills 11 million people a year. We know this data is so strong. It causes mental health issues, aggression, violence, depression, depression, anxiety, gun violence. I mean, the studies are there.

I did a podcast on The Doctors Pharmacy, in my podcast about this, talking about how our food is affecting our mental health. health, not just obesity and diabetes, but our cognitive function, ADD, and memory issues. I mean, it's all linked to what we're eating. So we have a, you know, like I said, the best of times, the worst of times. We know what to do, but we have the ability to do it. It's a problem of education, a problem of a political will to change the policies that are

driving us to do the wrong thing. And right now there's a bill being proposed in Congress that would limit, as a pilot, ultra-processed food for kids with food stamps, which I think would be amazing. The food industry is fighting back tooth and nail, right? So we're fighting big forces. The food industry is the biggest industry on the planet. When I was growing up and I was trying to be healthy, one of the things I used to do was chug milk.

Yeah. Because I got told that it would make me tall like my brothers. So I used to drink milk like crazy. Yeah. Straight from the carton, just as many gulps as I could take from the first. Did you work? Did you grow? I have no idea. I'm still shorter than they are, so I guess not.

But that's one of the big myths that I think a lot of family still believe that milk is great for our bones and to help us grow. What's your thoughts on milk? Yeah, so it's a controversial topic as well, subject of milk. Yes, I mean, yes. I mean, the dairy industry is big. Our current Secretary of Agriculture worked for the dairy industry. It's problematic because the science isn't there. There was a paper called Milk and Health that was published in the New England, medicine, top medical journal in the world, arguably, maybe the Lancet, if you're from the UK.

But it basically was written by two Harvard scientists that dissected all of the scientific evidence around milk and whether the claims were right or not. And just maybe for the audience in Europe, you might not know this, but in the States who'll remember this, there were all these got milk ads. So there were famous people, celebrities, you know, sports athletes, politicians all wearing a white milk mustache. And they're like got milk as a promotion. And in those ads, it would say it's going to build better bones. It's going to do this. It's going to do that. And the FTC, the Federal Trade Commission, actually, or I think it was the federal trade, you can't do that because it's not true. Like, you have to take those ads out. So this ads went away. And it was the government promoting those ads with the Dairy

Council. So there's something called checkout programs that the government has where it's supposed to support agriculture. Well, the government was paying in part for these ads with taxpayer dollars, and the science wasn't there. And the dietary guidelines for Americans says that the average American should have three glasses of milk a day, and kids should have two glasses in milk a day to be healthy. You cannot get money in funding for school lunches in America without having milk on the menu. Now, there is no evidence to support this. In fact, there's opposite evidence that Skin milk causes weight gain because it doesn't satisfy your appetite, that milk can cause cancer.

Prostate cancer. That it doesn't create strong bones. In fact, there's higher risk of fracture with high milk drinkers. That it creates a lot of digestive issues for people. It can create autoimmune diseases like type 1 diabetes. It has common allergies or food sensitivities that people get. And I remember I was in the emergency room once, and when I was working in the ER and this mother comes in with this kid with like,

you know, had like this 10th ear infection. I was like, what happened? Like, when did this start? Oh, it started when he was like 12 months old. I said, what changed? Well, I stopped breastfeeding and I started giving him milk. And all of a sudden he started getting his ear infections. I was like, oh, this is before I even knew about all this.

It was just kind of an interesting footnote. But we really have to look at the data and be science driven. And the problem is we have corporate capture in America. Where the food industry has captured our food agencies, our political. system from the FDA to the USDA. They spend, for example, half a billion dollars just on the farm bill, which has, for example, food stamps and other food programs, child infant nutrition.

So it's really unfortunate, but milk is not nature's perfect food. It's only nature's perfect food if you're a calf. Is there health benefits to milk? Yes. So that's the other side of it. Now, what milk should we be drinking, right? If we're drinking modern milk, modern milk is from Holstein cows that are almost homogenous, is in the same, not homogenized milk, but homogenous breed.

They have very few bulls inseminating them. They have, like, you know, massive insemination program from very few bulls that have a limited genetic stock. And they're what we call A1 cows. So most heirloom cows, most sort of historical dairy, had something called A2 casein, which is less inflammatory, less likely to cause gut issues. less problematic for the body. So sheep and goat milk have A2.

Certain cows like Jersey or Guernsey cows have A2 in them. And you can get A2 milk. You can A2 ice cream now. And so this A1 casing is potentially very problematic. So I think the current dairy is not great. And then we pasteurize it and homogenize it and that we, you know, and we add growth hormone to the cows. That goes in there.

We have estrogen that we add into the cows. It's in the milk. We have 60 different hormones in the milk, some of them naturally occurring. But we milk pregnant cows, and milk has a lot more hormonal effects. So I think current dairy is not something we should consume. Now, if you have a chance to get sheep milk or goat milk or A2 milk from a cow, that may be okay. Yogurt's may be okay. And it depends on your genetics too.

75% the world's lactose intolerant. Many people have dairy sensitivities. But I think, you know, if it's from the right source, it's okay. for example, I use goat way as my morning protein shake. So goat way is from goats, obviously. There's very little casein in it, but it's A2 casein if there's any, and I don't react to it. But if I have regular way, I do have a reaction.

I get congested. I'll get pimples or I get regular stuff. So I don't think dairy is something we should be consuming in large amounts unless it's certain kinds of dairy. What's your position on fruit? I love fruit. How much fruit? I think it depends, right?

So if you're a diabetic and you're metabolically completely. out of whack. And you don't have any metabolic resilience. You know, eating a plum might be a problem for you. And now we have continuous glucose monitors. You can track your blood sugar and see. And I've had patients like this. Gee, I eat a plum and my sugar goes to the roof.

So, but if I ate an apple, it doesn't. So I think different fruits have different effects on you. But for the most part, food is full of phytochemicals, fiber, phytonutrients. It does have a little bit of sugar in it. I would say no fruit juice. I think fruit juice is definitely linked to obesity and kids and other things. But if you want to have an apple or a peach or a plum, it's fine.

I think you shouldn't have it first thing in the morning. I think protein and fat in the morning is important because it activates your metabolism and your protein synthesis. If you eat sugar in the morning, which is essentially what we eat in the world today, cereal, pancakes, waffles, muffins, bagels, you know, sweetened yoghirts, sweetened coffees. I mean, it's the worst possible thing we can do for our biology. It jacks up our blood sugar and insulin and ends up causing us to gain weight and be hungry and, you know, be craving more stuff. So having fruit, for example, you have frozen berries in your, so I had frozen cherries, for example, in my weight protein.

That's okay. There's protein in there and it mitigates the effect. What about eating times? When to eat? Yeah. Have you got any thoughts around when we should and shouldn't be eating? Yeah, for sure. I think, you know, we had something called breakfast before, which was breaking the fast.

And now people eat all night, they eat until they go to bed, and they assume they wake up, they eat or have something, sugary stuff in the morning like a sugary coffee. And they don't get themselves a window of fasting, which is critical for our biology. And I wrote about this in my book Young Forever, where we talked about how do we have our own repair renewal system kick in? Because the body, think about it, Stephen,

your body, when you cut yourself, heals. The skin closes it heals. How does it know how to do that? It's so smart. It's got your bones break. It heals, right? I broke my heart a few years ago. It just healed, right?

What's going on? I'm not going, would you please heal in there? It knows what to do. I recruit stem cells or recruits repair factors and growth factors, and it knows what to do. So the body has this innate healing, repair, renewal, and regeneration system. And we need to learn how to activate it. And most of us do the opposite. We do everything in our power to deactivate it, and that causes a disease.

So food is the most important thing we do to interact with. these regenerative renewal repair systems. It's one of the things we call the hallmarks of aging, and there's one called deregulated nutrient sensing, and it really relates to how our bodies relate to food, how our nutrient sensing systems are dysregulated by our highly processed diet by high sugar and starch, and not enough of the right foods. So in the long answer to your question, you know, it's important to give yourself a break of 12 hours. So if you eat at six at night, you can eat six in the morning, minimum. but best probably 14. So if you eat dinner at 6, eat breakfast at 8, that's okay.

That's a 14-hour fast. And in that time, your body is doing its cleanup recycling repair. Is there an evolutionary story here? For sure, absolutely. You know, when, you know, we didn't have grocery stores, we didn't have, you know, whole foods, we didn't have restaurants, we didn't have takeout, we didn't have convenience stores. So we had to go out and find food. And I just came back from Tanzania and visited the hunter-gatherers there, the Khadza,

which is one of the last few tribes that hunting gathers. and we went to hunting and gathering. I was like, man, it's a lot of work to go, you know, dig up some roots and kill a bird in the tree. And like, it was a project. We ran around for hours. And so we don't know where we're getting our next meal. And so the body has had to deal with periods of feast and famine before.

And so what it's got built into it is a system of conservation and repair when we don't eat. And so the system gets activated that improves our blood sugar control. that recruits new mitochondria and builds new mitochondria that reduces inflammation that activates cellular cleanup and repair processes. So you have all these old cells and damaged proteins. Your body has a little like digester, almost like a little vacuum cleaner that goes and sucks this all up

and then digest it and then uses the parts. It's almost like a recycling system in the body. We need to activate that. And so that fasting period is a time to do that. And we've seen even, for example, we know, for example, concentration camp survivors who live really long. Like, they live 90, 100 plus years old, many of them. And it's because they had this period of deep starvation that had an effect on their biology.

And we know this from many animal studies that starvation and fasting will extend your life by a third. If you eat a third less calories, you'll live a third longer. Now, it's not fun, right? But you don't have to do that. So timing of eating is important. So give yourself three hours before bed for no food. and give yourself at least 12 to 14 hours between dinner and breakfast.

How do we know in the animal studies it wasn't just the calorie restriction that caused the sort of longevity effect? It was. Oh, it was the kind. It was. So what if I just restrict my calories instead of fasting? Well, you can do that. I met a guy who was from the calorie restriction society.

There's a calorie restriction society? Yeah, which is based on these research in animals where, think about it, if you eat a third less, you live a third longer. So for a human, that would be 120 years old. And I said, what do you have for breakfast? He said, well, I had five pounds of celery. And I'm like, okay, you go do that. I'm going to figure out another way.

So you have to eat enormous amounts of like low calorie food just to feel full, right? That's why you all have food. So he was starving. And there are a lot of downside to starving. You lose muscle, which is necessary. There's certain things that go wrong. And so it's not really the optimal strategy. You want to do things that mimic starvation.

So how do you mimic this period of starvation that causes something called autophagy, which basically means to eat yourself, to basically clean up yourselves? It's like self-cleaning or self-repair, right? And so there's a lot of ways to hack that. You can do it by this longer term overnight fast. You can do it by certain supplements and certain medications like rapamycin's being studied for longevity, which is a drug that's used for cancer and for other immune suppressing treatments, but it works on this pathway called mTOR, which essentially is the activation of cellular

build up. It causes muscle synthesis. So if you want to build muscle, you want to activate mTOR with protein, which is good, but you don't want to activate it all the time. So this drug inhibits mTOR, which is what happens when you starve yourself. So it mimics starvation. And then you get this kind of benefit or drugs like metformin are being studied, which is another drug that's looking at how do we activate this longevity switch called AMPK, another pathway, that's regulating your nutrient sensing. So when you have enough, you don't have enough nutrients, this activates. But if we're running around eating, well, you can actually take this drug and it may have an effect. There's a large trial going on now. I'm still agnostic about it. I'm another pro or against it. I think the data

is not in it for me to start taking it or for my patients to start taking it. But it works on some of these sort of starvation mimicking hacks, let's call them. So starvation is good for us. Yeah, I mean, yes, yes. I would say you have to be careful because, you know, people go really to the extreme. They go like, I'm going to not activate mTOR because activating mTOR caused me to age faster and it prevents autophagy and it builds cancer and it's bad. So I'm going to become a vegan and I'm going to eat less calories.

and eventually what happens is you lose muscle. So it's like Goldilocks. You know, you need both mTOR activation and mTOR ambition. You need to take a breath in, you need to take a breath out. You need to be awake, you need to go sleep. Yeah, your heart needs to beat and needs to relax. It's just how the body works. What you just listened to was a most replayed moment from a previous episode.

If you want to listen to that full episode, I've linked it down below. Check the description. Thank you. Oh,