Dr. Richard Johnson: A conversation on the Fat Switch and what we can do about it
Dr. Richard Johnson, MD, FACP is Professor of Medicine Renal Disease & Hypertension at the University of Colorado. He also serves on the Scientific Advisory Board of Blue Oak Nutraceuticals, Inc. Dr. Johnson has published more than 550 peer-reviewed publications. He is also the author of several books including, Nature Wants Us to Be Fat, The Sugar Fix, The Fat Switch, and Comprehensive Clinical Nephrology.
Note: The content has been lightly edited for readability and conciseness.
You've written a lot, including books, on the Survival or Fat Switch. Tell us more about your discoveries on the Fat Switch.
Dr. Johnson – Most people think that the reason you gain weight is because we eat too much and we exercise too little. So, it’s supposed to be kind of a simple thing. It’s driven by poor behavior where we select foods that we know are bad, but we still go ahead and do it, and then we gain weight. And it’s that simple.
But, over the years, it’s become obvious that this is not so and it is unlikely to be the mechanism; there must be another way that triggers weight gain.
What we did was to start studying animals in the wild and we noticed some animals purposefully become fat, they do so in the fall before winter, and like the hibernating bear will gain a lot of weight. They become insulin resistant, get fatty liver, and all these things that we think of as unhealthy. But for the bear, it’s actually important for survival. And so as we studied this, we tried to understand it, and we realized that there’s a switch, which we call the Survival Switch, that animals can activate.
And when they do, they become extremely hungry. They forage for food, they store fat, they become insulin resistant, and then they’ll turn off that switch right before they hibernate. And so then when they hibernate, they go from storing fat to burning fat.
I’ve written a book on this, titled, The Fat Switch.
We’ve done a lot of research on it to identify what causes that switch. And we’ve been able to show that the switch is actually what’s causing obesity in humans.
How can a person turn the Fat Switch off? Or, is it even possible to turn off the Fat Switch?
Dr. Johnson – That’s a very complicated question, because in order to understand it, you actually have to know how the switch works. So let me tell you a little bit about how the switch works.
The classic thought was that the way obesity occurs is we eat food, which is a type of energy. And we make energy from the food we eat. In our bodies there are these things called mitochondria and the mitochondria are energy factories. And when we eat food, the food’s broken down and used by the mitochondria to generate energy. And this gives us the energy we need to run and to hike, to sing and talk and think and do everything we want.
The theory was that obesity is where you just eat too much. So the energy builds up –- like filling the gas tank — once all the ATP is produced, the extra energy gets spilled over and has to go somewhere. So they store the energy and the energy is stored as fat. So according to this thinking, obesity should be a high energy situation. If you are obese, you should have more energy than you can imagine because you filled your tank and you’ve filled the reservoirs around you. So you should be full of energy, but you’re not.
Most people who are overweight or obese feel fatigued and have low energy. It’s not everybody, but many people do. And, what it’s been shown is that their ATP, or the energy being produced by the mitochondria, has been turned off.
The way this happens is by eating a certain food and that food turns out to be fructose. Fructose is distinct from all other nutrients; it lowers the ATP in the cell. Lowering the ATP (energy), it’s like the currency. It makes you hungry and it makes you eat more. But instead of the energy being turned into ATP, the energy gets transferred into fat, which is a stored energy. And the reason that is, is because the mitochondria are being turned off, they’re being suppressed. So the way obesity and metabolic diseases work is that you have to turn off the mitochondria.
There are different ways to reverse that switch. The best way, initially, is to avoid foods that contain fructose; the main foods that contain fructose are sugar and high fructose corn syrup and all the sweets and desserts and soft drinks.That is your major source.
Fructose is also present in fruit but the amount of fructose in fruit is really small compared to table sugar plus natural fruit contains substances that counteract the effects of fructose. And one of those is a substance called epicatechin. It is present in chocolate and fruit. And it actually helps turn off that fructose switch. It turns out this is the big discovery; it was very unfortunate because up to this point I was thinking it was mainly just sugar and high fructose corn syrup and I had it nailed.
I know how we can stop obesity, but the big discovery was that glucose and carbs can be turned into fructose. So, you don’t have to eat fructose, you can make fructose and make it by eating carbs. And, guess what carbs do? And it’s those ones we love – bread, pasta, rice, potatoes, all these cereals – things that break down to glucose.
When the glucose levels go up, the body says we don’t want the high glucose, we’re going to shift into fructose. And as much as maybe as much as a third of the excess glucose can be turned into fructose.
The fructose that’s driving the switch is mainly coming from carbs, it’s coming from the sugar and the high fructose corn syrup, but it’s also coming from carbs that make glucose.
A low carb diet or a keto diet is a fantastic way to turn off the switch. So if you want to turn off the switch, I would say go on a low carb diet, go on a keto diet; that will work or just cut back on sugar and high fructose corn syrup, ultra-processed foods and so forth.
What is the role of salt in dehydration? How does salt affect the Fat Switch?
Dr. Johnson – When we were studying what caused obesity, we discovered that it’s from fructose – it being the only nutrient that lowers the energy in the cell. But, it isn’t from the fructose we eat but also the fructose we make.
We became very interested in what turns on the process to make fructose. And, it is stress. Stress activates this pathway.
There’s different types of stress, for example, if you don’t get enough oxygen, the process to make fructose turns on because it’s meant to be a survival pathway. When you have a heart attack, your heart starts to make fructose which drives bad things because it suppresses the mitochondria.
Another example is dehydration. When you get dehydrated, your body wants water. And it turns out that fat when you break it down produces not just calories, but water. That’s why camels have a fatty hump. So that if they get into trouble, they can break that fat down to produce water.
That’s why whales have so much fat because they don’t drink sea water. They got to get their water from the food they eat. But, about one third of the water they get comes from the fat. So, fat is a really great thing to have to prove as a survival tool. But in our world, we’re eating so much sugar and we’re producing so much fructose that we are not just getting fat, we’re getting fatter and fatter. Then we’re diabetic, we get metabolic syndrome and dementia and all these things that we can track to this one pathway.
Salt turns out to be a way to create a feeling of dehydration. And so it activates the process as well. So when you give salt to an animal, it activates the enzymes to convert glucose to fructose.
If you go into a bar and eat a salted pretzel, that salted pretzel is used to help make fructose. Or, if you eat a plain potato, you can make a little bit of fructose; but, if you fry it and put salt on it, that’s French fries and it’s going to make fructose plus. When it makes fructose, it drops the energy and it’s going to make you hungry. And so the fat on the French fry becomes very attractive because it’s a calorie and your body’s activated to want to eat as much as it can. The fat switch is turned on and the energy is going to fat rather than to ATP.
Once you’ve activated the switch, high fat foods will get you fat very fast because the switch is on and you want anything that provides calories
If you turn off the switch, for example, by being on a keto diet, you can eat all the fat you want, you aren’t going to gain weight. You’re not going to get fat because you’re regulating your weight. You know when to stop eating.
It’s a complicated thing. I’ve written a book about our work, titled, Nature Wants Us to Be Fat that can help you dive deeper into it. This is the story.
What types of foods should we be eating so that we do not activate the Fat Switch?
Dr. Johnson – A lot of the foods we like activate the Fat Switch.
So it is impossible to eat cardboard, I mean you could eat cardboard, but you’re not going to be very happy. The reality is to realize that once you know what activates the switch, you can try to reduce the chances of activating it.
Some things you can eliminate; everyone should eliminate soft drinks.
Rob Lustig says soft drinks are poison. I agree with him. He is right on the money.
There’s certain foods that you’re going to want to have including some salt. If you are going to eat salty food, you can block the switch by drinking water because it’s the salt concentration in the blood that triggers the switch. When the salt concentration in the blood goes up, it activates the switch. So if you drink a glass of water before you eat, you know, a few French fries, you’re not going to activate the switch as much as if you just ate all the fries, got really thirsty, and then you went for it.
It turns out that once you’re thirsty, the switch which is inactive has been activated, so stay well hydrated. We showed in animals we could block the effects of sugar if we kept the animals well hydrated.
What is the mitochondrial connection to the Fat Switch?
Dr. Johnson – It turns out that the mitochondria are critical for how obesity develops. When you eat sugar or fructose, it acts to suppress the mitochondria. Therefore, the mitochondria make less ATP than they should. Any time you can stimulate the mitochondria to make ATP, you’re countering the switch. There are two phases. It is really important to know the way fructose suppresses the production of ATP is to cause oxidative stress. And oxidative stress stuns the mitochondria, so they don’t make ATP, but it’s transient, it’s temporary.
When the oxidative stress goes away after the fructose wears off, the mitochondria come back to normal. But, if you are eating sugar every day, you are suppressing recovery. What happens is that when the mitochondria recover, they only recover to 95% and then when you hit it again with fructose, the recovery only goes back to 92%. Eventually, the mitochondria are damaged to the point that they don’t come back; then, the only way you can recover the mitochondria is by stimulating the mitochondria to grow.
The classic way, which I recommend, is exercise. Exercise. This can stimulate the mitochondria. It is one of the best ways to do it, but there are other ways to do it.
And this includes substances that you can get as supplements like dark chocolate contains a substance called epicatechin and epicatechin can stimulate the mitochondria to grow. I’ve done some studies with epicatechin and it does definitely stimulate mitochondrial growth.
My first recommendation is exercise; these other things can help as well.