Diets. They work for some, but not for others. "You're just not on the right diet," purveyors of the latest trend will tell you. "You're just not on the right diet for your blood type, ethnicity, age, hair color," says another set of true believers.
So what's right and what's wrong?
Today on Fork U, a conversation between Dr. Terry Simpson, weight loss physician, and Dr. Bill Lagakos, nutritional biochemist and physiologist, where they expose the truth behind diets and why they may, and may not, work for you.
And check out Bill's book, The Poor Misunderstood Calorie.
TRANSCRIPT:
Terry Simpson: Bill, there are a lot of weight loss programs out there. The one that I'm hearing the most about most often is the Keto movement, which says that they're going to cure everything from heart disease and cancer.
Bill Lagakos: I think from a 30,000-foot view, Keto works for a lot of people. So does low fat. I like some of the recent work, the studies showing it's more about the level of processing of the food.
So you can have a vegan diet or you can have a Ketogenic diet and as long as it is excluding a lot of processed foods, it tends to not be over eaten. And people that tout the magical benefit effects of any of these diets, 99% of the time it's due to weight loss.
Terry Simpson: We actually had an experiment with Evo, who you met. He uhh did it several years, three or four years in a row for one month, Evo would go on a beer and sausage diet, rigorously kept his calories to 1500. We measured his liver function tests, his lipid panel.
Every year he lost weight, kept it off, and every year his liver function was fine, surprising with the number of beers he had a day, which was limited to six. But it was, he had weight loss and he had sustained weight loss over the year with a, kind of this funky diet we sort of made up.
Bill Lagakos: Well, that's terrific. And that's an awesome diet. I'm jealous.
But, uh, yeah, that, that basically proves the point. I mean, even if it's not a lot of weight he lost, I think a weight loss is a major driver in a lot of the health improvements that people like to attribute to particular dietary trends.
Terry Simpson: There doesn't seem to be a lot of long-term data in these diets. When I look at the sort of metadata, I see that if you eat really high on the low-fat side, you have a little lower lifespan. If you eat really high on the high-fat side, you have a little lower lifespan. If you have your carbs at about 55%, you seem to have a little longer lifespan.
Is there much good data saying one diet versus another, other than the Mediterranean, has great long-term results?
Bill Lagakos: I don't think so. I don't think it comes down to macros at all. I think that there's the confounding in those studies is so deep that I don't think the macronutrient composition of your diet is going to be what kills you in the end.
Terry Simpson: Part of your job is helping people lose weight. What are sort of the big messages you try and get through to people?
Bill Lagakos: One of the biggest things is the importance of adherence, which is why I try to say, you know, what do I know that, that you can adhere to 100%? It's what you've been doing because you've been doing it. So let's try and find the lowest hanging fruit that we can change so it doesn't turn your whole world upside down, which is something that would probably never work.
Terry Simpson: So in other words, you're not going to change a Keto into a vegan or a vegan into a Keto.
Bill Lagakos: Correct. However, I don't like to put those two at odds because there is, there have been a few studies on the vegan Ketogenic diet.
Terry Simpson: So give me an example of some of the things for our audience, some of the things that they can do to incorporate it in their life now to help them lose weight and just feel a little better about themselves.
Bill Lagakos: Well, feeling better about yourself and health outcomes and health profile, exercise can help with that a lot. I like to advocate all kinds of exercise. Cardio is good for the heart. Weights is good for quality of life and muscle mass, which also seems to bode well for quality of life.
In terms of diet, probably nix the ultra-processed foods. Nobody needs single serves bags of potato chips lying around the house.
Terry Simpson: Is that, that big, that great big bag? Is that the single serve?
Bill Lagakos: [Laughing] No, no, but I know people that will go through multiple single serves in one sitting.
Terry Simpson: Like when you see the Oreo cookie's just a hundred calories that you'd probably say it'd be better to have the apple?
Bill Lagakos: Uh, yes. Yeah. And actually, even when it comes to the apple, one of the studies that was comparing processed to unprocessed foods, it was very interesting. I was trying to figure out how are they going to do this? And it was like an apple versus apple sauce. And that's sort of not an obvious comparison, but the people in the apple group tended to eat a little bit less.
Terry Simpson: And when you start looking at, at some of the ultra-processed foods, are there some that you find that it has a lot of bang for the buck when you get people to sort of move away from them?
Bill Lagakos: Yes. Uh, the lowest hanging fruit there is obviously potato chips because, you know, it's all too common that someone will sit down for lunch, have a sandwich, you know, a diet soda, thinking they're doing something great, and then instead of taking a couple potato chips and putting them on the plate, they'll just open the bag and sit down in front of it and generally overeat a lot because of that. The potato chips just don't seem to hit the satiety button.
Terry Simpson: How about candy bars?
Bill Lagakos: Candy bars are, I don't know, for kids maybe, but I don't think adults should be eating candy bars. Or, if they do, very rarely.
Terry Simpson: That's the wrong answer, Bill. [Laughter]
Bill Lagakos: Hey, I'm okay with the sausage and beer diet. Isn't that enough?
Terry Simpson: When they hear us talk about that people will, you know, and Evo wrote a book about it, people say, "Oh, I can have all I want." And it's like, it's not all you want it. You know? I mean, Evo was...
Bill Lagakos: Right, as soon as you told me that he lost weight on it, I was instantly convinced that that could definitely happen. That's very feasible for your health to improve because you're losing weight. You can eat pretty much every diet.
I think there was a, there was a McDonald's diet where the guy over ate everything and it was a TV show and he got very sick, and somebody else did the McDonald's diet and they underrate at every opportunity and they lost weight and got healthier.
Terry Simpson: What you're saying is, increasing fiber in the diet seems to not only help you from a satiety sense, which then keeps your appetite smaller, but provides a lot of health benefits because you're going to lose weight.
Bill Lagakos: Yeah, I'm trying to move away from the word fiber, because if that was the plainest form, then Metamucil would've solved the obesity epidemic decades ago. And it seems to be like whole food based fibers seem to be the way to go. Not like an isolated fiber powder, for example.
Terry Simpson: We see some of this problem in our weight loss surgery patients. So we start out weight loss surgery patients on what I call "formula," which is our version of some protein shake of which there are about a thousand out there that'll sell.
But when patients come in and they haven't lost weight, they'll say, "Well, I'm going to just have more shakes," and it's like that's, you know, we, we, we would rather have them have some beans or, or something rather than the shakes.
Bill Lagakos: I agree with that. That's, that's good, sound advice. The other thing that you mentioned is the shakes is something that I tend to, I don't rail against this movement on the social media, as people are starting to catch onto higher protein diets, which I tend to like that. You know, have a couple, three servings of protein a day seems to do well. Protein does seem to hit the satiety button quite well.
And all of the hysteria about the kidney health leeching calcium from your bones, any of that stuff, I mean, the only thing that might be remotely true is from the KDOQI studies on the people with end-stage renal disease might have improved outcomes changing their protein intake. But even that is not 100%.
Terry Simpson: We're pretty good at processing and breaking down protein and eliminating too much of it. We don't store it. So it tends to be when we can store my macronutrients that we have problems.
Bill Lagakos: That's a good way to look at it.
Terry Simpson: I want to talk to you a little bit about fatty liver disease. Uh, it's something that we in weight loss surgery see a lot of and, and we're usually the first ones to diagnosis. We're never surprised when we see it. We open up people and take a look at them with our scopes, and we see these, this fatty liver disease and we take biopsies and some of these people are fairly far advanced.
Then, sometimes we have to go back and look at them again, and all of these people who have lost weight. And there will be some people who have, still have bad fatty liver disease. And there are other people who have not. We'd like to think that it's, uh, some dietary thing between them. But, but clearly there's a combination of diet and genetics that are there. It's not just all weight loss. What're your thoughts?
Bill Lagakos: There, there's an interesting overlap. I saw, it was a correlational study and it was alcohol consumption and post uh bariatric surgery, and there seems to be sub, the sub-population that tends to drink a little bit more alcohol, and alcohol is definitely an independent risk factor for fatty liver.
Terry Simpson: Yeah, there is a slight increase in alcoholism, one of the things that we have to screen for is alcohol abuse, and then afterwards is alcoholism. Because with some of the weight loss surgeries, when you drink, especially the ones that are, like the Roux-en-Y Gastric Bypass, or the One Anastomostic Gastric Bypass, the alcohol hits the small bowel much faster. People feel better much faster. And then, as all of us know, once you feel better with the alcohol, you want to keep it going. The difference is is that if you have a full stomach, you're not going to feel that right away and you can absorb more and you're not going to drink as much. These patients, we think, we give them a much faster avenue to that high.
Bill Lagakos: That's interesting. That's unfortunate. And I'm glad to see that, you know, it's on your radar and you're doing the screening. But that's also going to put them at much greater risk of that fatty liver.
I once heard a doctor who, similar to your case, I think I was a student when I asked this, I said, well, what's the difference? Why do they call it non-alcoholic fatty liver disease versus alcoholic fatty liver disease? What's the difference? And he told me patient history.
Terry Simpson: What do you think about Lustig's comment about the highly unprocessed fructose causing, in some people, a high degree of fatty liver disease?
Bill Lagakos: I don't know. It has to be consumed disproportionately very high. It is rarely found like that in nature. Like, you know, I guess Lustig said, it's just the high fructose corn syrup. If it's in a big energy excess, possibly contributing to fatty liver? By restricting fructose you're probably also restricting glucose and hopefully, and if you're creating an energy deficit in that context that could help clear the fatty liver.
I think, uh, the, his, his stance on the whole, whole food based fruits and stuff, that's a good take, a good avenue. Even on the low carbohydrate approach I don't think that people should be, be abandoning, you know, low carbohydrate, low starch fruits and vegetables.
Terry Simpson: But I do remember my first foray into the Atkins diet, which was many, many years ago, you know, it's sort of like don't eat these fruits, don't eat these vegetables. And I always wondered why would you say that?
Bill Lagakos: Right, right. And I think it's sometimes some of the more recent Atkins advocates took it a little bit too far and said, you know, no fruits and vegetables at all because there's no carbs in eggs and poultry and steak, so we'll just stick to those.
I think that sort of took the movement a little bit too far because even the Zone diet study was a low carbohydrate, what I would say would be a well-balanced low carbohydrate diet versus a Ketogenic diet, and the people on the low carb actually did a little bit better.
Terry Simpson: And do you think that was because of the satiety with the whole foods?
Bill Lagakos: Could be, it could be. I mean, fat is, uh, dietary fat doesn't seem to be like a super satiating nutrient, and it also seems very easy to passively over consume.
Terry Simpson: Yeah, my brother-in-law brought a whole bunch of baklava over. I can, I can atest to that.
Bill Lagakos: [Laughing] Delicious.
Terry Simpson: I remember the, you know, when I, I think I was a college student when Atkins came out and I thought I had to lose five pounds because in those days that seemed to be the thing I had to do. Oh to have those days back again.
But, I remember I was shocked when I went to Italy my very first time and here are all these beautiful people eating pasta and not getting fat. And it's like, this can't be. How can this be?
Bill Lagakos: Yeah, I think the food environment has a lot to do with it. Like, you know, the, the memes, you see these on the internet, you know, when you go to the grocery store, you're bombarded with all these colorful flashy ads to get all this junk food as much as possible. And the food companies are trying to sell their product, so of course you're going to be advertising and have focus groups and whatnot. I do think that the food environment has something to do with it.
Terry Simpson: Well, I also think that when you look at what they're actually eating with their pasta, they have a lot more vegetables and a lot less fat in it. And their fat is predominantly olive oil. Whereas with our pasta in the United States, I mean, when you look at spaghetti and meatballs in the United States there's an awful lot of meatballs. Where they might have one in a dish, we'll have half a dozen.
Bill Lagakos: And that's also going to contribute to the calorie imbalance.
Terry Simpson: It's coming down to calories in some sense, is that what the calorie man is saying?
Bill Lagakos: [Laughing] It's hard to get around that. I mean, people get that, people get there in different ways. Like some people will feel a lot of satiety on like a whole food plant-based diet and that'll drive their calories down. Some people will get that way with the Ketogenic diet and that gives them an incredible amount of satiety. So it drives the, the calorie intake down.
It's kind of like how you get to that end point is the purpose. I have seen some debates that showed there might be some differences in sort of metabolic efficiency, calorie absorption efficiency, but I tend to think that might account for a couple hundred calories tops? And it seems that might not have a huge influence if somebody is over eating 500 calories, but then maybe 200 calories aren't absorbed as well. Or they have a greater thermic effect of feeding, I guess it could put a dent in it.
Do you know how gastric bypass cures this, cures diabetes so quickly?
Terry Simpson: Well, I don't know that it's the gastric bypass that does it. I think that because every weight loss surgery does it, whether it's the lap band that we hardly do any anymore, or the gastric sleeve, which is the most common, or the bypass or the One Anastomosis bypass, or the Duodenal Switch, what they all have in common is you're eating so little. You're in such a huge calorie deficit for the first couple of months that you're going to burn through your glycogen.
Bill Lagakos: Oh, from day one.
Terry Simpson: Yeah, and so you're burning through your glycogen very quickly, and then you're starting to use up your fat stores. So I think that's kind of the magic. So, you know, for awhile we thought there was something we bypass in the first part of the intestine that did it. And it seemed to work out in mice, but it's never worked out in humans.
Bill Lagakos: I met, I met a girl who was a wizard surgeon and she was taking one part of the intestine, putting it in a different part of the intestine, taking, you know, an inch of mouse intestine, reversing it. And she, she provided a compelling case that in the mouse, it could be when the nutrients are hitting which part of the intestine was having some of the effect, but it -
Terry Simpson: But it never works out in people.
Bill Lagakos: Right. In people, in people it just seems it's such an easier, what do they say, Occam's razor, you know, you're in an instant energy deficit. It's something that you probably haven't been in in years, maybe decades, and now you're finally seeing shack clearing out of, uh, ectopic sites like the liver, muscle.
Terry Simpson: Yeah. And they just seem to, and they just seem to get better. And so we , if you're in the Roux-en-Y Gastric Bypass camp, you will repeat the mantra that the Roux-en-Y Gastric Bypass is a cure for diabetes. But if you're in a camp of, we will do whatever weight loss surgery will, they're all in our toolbox, you see every single weight loss - Or when you have weight loss, cures diabetes.
There, obviously, there are those patients who you can do a gastric bypass on, and after a few months they regained, they regain their weight. That's not a majority, but those people don't tend to cure their diabetes.
So I do think the magic is the body weight. That, I think, is a great cure for insulin resistance. I sort of look at it like your fat cell is a sponge which will soak up insulin. The smaller you make your fat cells, the less surface area there is, your insulin will work better.
Bill Lagakos: Sure, sure. And insulin is very good at making fat cells grow. It does it at a much lower concentration in the blood, than, for example, it causes glucose uptake in muscle.
Terry...
Our TOPPODCAST Picks 
Stay Connected
