One of the biggest things I realized with the low-carb or keto diet, is that your hunger completely goes away. This is so different to other diets, which are calorie restrictive, you feel like you’re starving, and they’re not sustainable. Could you explain why and how the hunger goes away?
A lot of people don’t believe it. A lot of people say if it’s too good to be true it can’t be true. Well, that’s not true! With a low-carb diet there is no hunger. For the vast majority of people there is a great reduction in hunger so that you automatically eat less compared to what you were eating before, and that’s why it’s known as a weight loss diet, predominantly. When you get to the appetite suppression level, it’s pretty amazing. It’s different than most higher-carb, lower-calorie approaches, because unless you really ramp up the fiber or you have to manipulate things, you’re going to be hungry.
We know for any weight loss program that hunger is the thing that makes it not work. If someone is struggling with hunger, a program is not going to be successful in the long run. Typically that’s why many doctors will actually prescribe appetite suppressants and hunger suppressants when they’re using a diet that has carbohydrates. But we prefer to not use medications and just use a keto diet. It is a fundamentally different feeling when you’re on a keto diet for weight loss, because you don’t have hunger.
Do you know the mechanics of why this actually happens?
Not really. This is one of those, ‘If you don’t know the mechanism, it can’t be true’.’ Well, there are things that happen that go along at the same time when the hunger goes away. The insulin goes down, the ketones typically go up, and then leptin and ghrelin—all of these hormones that have to do with hunger and feeling full—change. There are so many things that change. You can’t just give one of them and see all of the effects. Some years ago, talking to other researchers who actually knew Dr. Atkins, who said ketones were what caused the hunger to go away, they as researchers gave intravenous ketones and didn’t find an appetite suppression effect. So they said, “Ah, the diet can’t work.” But, it still works even though the actual mechanism of hunger going away—the one hormone or the ten hormones that change—is not really known yet.
I’m hopeful, now that we can actually study the low-carb keto diet, that that will be discovered. I mean, that might be a huge discovery or a new pill to give people, if you can find the secret that takes away hunger on a low-carb keto diet. That said, there’s a whole phenomenon of some things that you eat that make you hungry. Have you ever had the experience of having candies, like jelly beans or Skittles, which are just pure sugar, and you can’t stop eating them? It makes you want more and more and more. It doesn’t fill you up. So on a keto diet, you’re getting rid of most of the foods that induce hunger. That might be part of the reason why the hunger goes away—you’re not eating the foods that stimulate hunger. I have to say that not for everyone does it go away completely, but just about everyone will say that there is a lot less hunger than before. Again, while the mechanism isn’t known, I’m hopeful we’ll find the actual mechanism and then use that to our advantage in other situations.
For folks just starting out on this type of program, how long should it take before the hunger goes away?
In just a day or two the hunger is gone or dramatically reduced for, I would say, 90% of people. There’ll always be the tail end of the bell-shaped curve as we call it, or the outlier, and those tend to be the people who chime in on Facebook groups a lot! I can give people a more clinical reality. For most people it’s just a day or two, the hunger is gone, cravings are gone for the most part. These are very real phenomena, you may not be hungry but you crave something like fruit, bread, pasta, rice. These can be very strong. In fact, a lot of people are worried about giving up these foods because they don’t know how they could live without bread, pasta, and rice. Remarkably—almost unbelievably—in a day or two the hunger and cravings are gone. Put another way, if you’re starting out and you get good information on how to start, like quitting smoking, cut out all the carbs, like cutting out all cigarettes. If it’s not working within a day or two, or a week at most, then something’s not right. You might be on a medication that stimulates hunger – insulin and steroid medicines are the most common ones in my world. Others might be antidepressants or pain medicines that cause hunger as well. There’s a saying that if what you’re doing isn’t working within a week or two for either hunger suppression or weight loss, find something else. All too often I see someone who is in a program for a year, they’ve only lost five pounds, and the program just says, “Hey, stay in there!” That’s not not good enough. It should be just a few days for the hunger and no more than a week or two for substantial weight loss if that’s why you’re doing it.
You’ve got a saying, “Eat when you’re hungry and stop when you’re full.” Tell us how you got to that.
I fight the teaching that people have received for so long and I sometimes have to come up with dramatic sayings like that, that are so simple it’s pretty obvious. Why would you eat if you’re not hungry now? Why would you drink if you’re not thirsty? There’s a big part of a keto or low-carb or just any general healthy eating program where I believe you should become more in tune with what your body is telling you. If you’re not hungry, don’t eat. I fight this in North Carolina and in the US all the time. It’s probably the most common reason this kind of diet isn’t working for weight loss: people are eating when they’re not hungry. They’re “programmed” to eat three meals a day, with snacks. If they have diabetes, they’ve been taught that for 20 years. We go against that teaching. There’s a weird thinking out there that the less you eat, you go into “starvation mode” and then you won’t lose weight. All you have to do is watch reality TV shows where people go to deserted islands and don’t eat anything and they lose a pound or two a day.
The job I have really is to get people to eat less—comfortably, and with great, satisfying foods. I do fight the, “I have to eat three meals a day” notion. Depending on the person, I might even ask if they fill up their gas tank three times a day when their gas tank in the car is full. It wouldn’t make sense to just keep going and filling up the gas tank. When you have access to your fat stores in your body, when you’re a fat burning machine, then you don’t have to fill up three times a day. I don’t mind if someone’s eating one or two meals a day. If you skip breakfast and you’re not hungry, that’s fine. It takes most people three or four times of hearing that for it to sink in, that if you wake up and you’re not hungry, you might have coffee and cream and that’s all. That’s fine, because you’re already burning body fat.
Occasionally someone will be so appetite-suppressed that they don’t want to eat anything. My teaching says that that’s not the healthiest way to go about this. You want to eat some protein every day. We don’t know exactly how much, and fortunately for most people it’s matched to that individual, so most people have a reduction to one or two meals a day and then their protein intake will be determined by their size, their hunger, and not based on habit. It’s silly—people look at their watch and say, “Oh it’s time to eat,” when, no, it should be based on your feelings internally.
Do you think this is one of the main reasons why people lose such a lot of weight on a low-carb diet? If the hunger is going away, the idea is that you are restricting the calories without even knowing it?
Yeah, that’s the secret, which is not a secret! You eat less so it becomes a low-calorie diet compared to what you were eating before, even though you’re not counting or consciously restricting calories. Most people eat somewhere between 1,200 and 1,500 calories per day, automatically, and that sits in the scheme of things as a low-calorie diet.
Once you are burning your own body fat, can you become more effective at burning fat over time, or does the original rate stay the same?
That’s an interesting question. I don’t think enough research has been done there. A lot of theoretical work is being done. People will say, “Based on prior studies, this and that will happen or should happen.” We don’t know. It would make sense that you become a better fat burner. This is one reason why we don’t think the ketone level in the blood is the be-all end-all because if you’re using ketones really well, you’re not going to have a high level building up in the blood. This cries out for more research to know how effective fat burning is and whether you improve it over time. I know you can stop it really quickly by eating carbs, so it’s a sensitive situation. A little bit of sugar or starch can stop the fat burning.
Dorothy says: “I’m pretty much on a low-carb diet and the 20 grams total carbs most of the time. I occasionally fall off the wagon and indulge in a high carb day. When I do this I’m ravenous for the next couple of days. Is this normal?”
Yes, eating carbs brings back the hunger. Let’s backtrack… You go on a keto diet, the hunger goes away after a day or two, life passes, you’re losing weight, a birthday or some celebration comes up and you eat some carbs, well, that brings back the hunger. For most people it’s just a day or two, but for some people a week. It’s getting back into that sugar burning mode, so you have to burn that sugar off and then you can’t burn your body fat. It’s working against your fat loss and fat burning.
We’ve only done one preliminary study where we looked at how long people were knocked out of ketosis and there’s a wide range, so we typically teach that if you eat some carbs, for a day or two you won’t be able to burn fat. Some people may not be able to burn fat for a week. That’s where the individual variability, how you feel, is important. Being fat burning and having cravings and hunger actually can be different too. You might be back in ketosis but you’re still craving those foods. It seems like a different mechanism to me. The main point is to not do that!
Holidays are when people generally early on in the first year or two, will have carbs and then I just help discuss what happened, how it felt. Most people don’t feel good. They get brain fog or fatigue or “carb coma,” as we call it, and it’s important to learn from that. If you have a big weight loss journey or you want to do keto for life for other reasons, my best advice is to stay away or don’t have those carbs very frequently.
Mary asks: “Sometimes I’ll skip meals without knowing it and I can get along just eating one meal a day. Is this unhealthy?”
Depending on what else you’re eating, it’s fine. A lot of people who come to my clinic talk about intermittent fasting or time-limited eating where they only eat one meal a day. I think that’s fine as long as you’re not hungry. I don’t think fighting through hunger and then eating one meal a day is a good idea. My teaching says eat when you’re hungry; don’t eat if you’re not hungry. If that leads to skipping meals, it’s not “skipping meals,” because you don’t have to have them. One meal a day is fine as long as you’re eating a great nutritional pattern that includes all the proteins and the essential fatty acids you need. That’s another thing I help people unlearn. It’s okay to eat once a day.
Stepping back, I have learned a lot by going to various meetings. I do remember meeting a lion researcher in Cape Town. It was the first meeting Prof. Noakes put on and I asked, “Tell me more about the behaviors of lions.” And it just shocked me to learn that lions eat once a week! It makes sense. They can’t go to the refrigerator or pantry and open the door! The idea that you would be eating three meals a day—“three square meals and snacks”—makes sense if you’re a carb eater and a carb burner, because you have to be constantly feeding yourself with sugars, but it makes no sense, metabolically, that you’d have to eat that often.
Ted asks: “I started a keto diet about three weeks ago and I’m still extremely hungry. Am I doing something wrong?”
If your hunger is still there after a couple weeks, something is wrong. But I don’t know that “wrong” is the right term. When I troubleshoot, the first thing I want to know is how someone learned about keto. The new view of what keto is in the year 2020, involves adding oils and keto products, looking at net carbs, and I don’t think any of those things are necessary. You might be able to do that, but often all I need to do is reorient people to the ancient, 150-year-old, low-carb keto diet based on real foods, and that fixes them. Medications are also a prime cause for hunger persisting.
I’m reminded again of an interview in South Africa where we were on a radio show and the interviewer on the other side of the table was asking people if they were doing the Banting keto diet. The first thing for me to know is what you’re eating and drinking, breakfast, lunch, and dinner. That’s going to tell me what someone’s doing, where the issues might be. The person on the line said, ‘Well, in the morning I’m having some cereal with berries,” and even the announcer looked at me and said, “That’s not keto!” So, the first thing is to really make sure what someone’s doing. The main thing about keto is to keep carbs low. Don’t add things. If someone has nausea or gas and bloating, it’s usually something they’re adding to the food. If you’re having trouble, take advantage of all of the keto coaches and experts that are available now, because these things can usually be easily solved.
You can watch the video here.