Diet Myths: Are Carbs Bad? Are Fats Good?

Jim Hill: Welcome to “Weight Loss And…”, where we delve into the world of weight loss. I'm Jim Hill.

Holly Wyatt: And I'm Holly Wyatt. We're both dedicated to helping you lose weight, keep it off, and live your best life while you're doing it.

Jim Hill: Indeed, we now realize successful weight loss combines the science and art of medicine, knowing what to do and why you will do it.

Holly Wyatt: Yes, the “And” allows us to talk about all the other stuff that makes your journey so much bigger, better, and exciting.

Jim Hill: Ready for the “And” factor?

Holly Wyatt: Let's dive in.

Jim Hill: Here we go. Welcome to another episode of “Weight Loss And…” This is Jim Hill. I'm here with Holly Wyatt, and we're talking about weight loss, how to achieve it, and how to maintain it. Holly, today we're going to tackle a question that I love about what you should be eating, what's the composition of the diet you should be eating, let's structure it around two questions. Are carbohydrates bad for you and are fats good for you?

Holly Wyatt: Yes, I think this is a question lots of people ask and there's so much mixed messaging. Should I be eating carbs? Are they good for me? Are they bad for me? Same thing with fats, we've heard. Are they bad? Are they good? There's so much mixed messaging out there that people are confused and they don't know what to do. So I think people are interested in that. We hear that you need to eat some carbohydrates. We hear that sugar is making you fat. We hear that saturated fat like butter is bad for you. We're from Alabama. If we say butter is bad (butter is a food group here), it's really hard to know what should be eating and what should I consume. You've got to eat something.

Jim Hill: If you look at the fads, we alternate. We've only got three things to focus on carbs, protein, and fat. Depending on the era, one or the other is popular. I remember in, I guess it was the 70s and early 80s, where everybody was saying low-fat, low-fat this and that. Today, maybe it's a little bit more low-carbohydrate. So these things are popular. The question is, what is the right diet for people who want to lose weight and keep it off?

Holly Wyatt: So it is complex, and it is sometimes hard to get our hands wrapped around. Let's take one question first. Let's take, are carbohydrates bad for you? Because I hear that out there. Carbohydrates are the problem, they're bad for you, and you need to limit them. Many individuals are currently reducing their carbohydrate intake, consciously limiting the consumption of this food group and related products. So what do we know about that?

Jim Hill: Let's start with the science. We always like to start the science and hopefully make it understandable. So when you eat carbohydrates, three things can happen. You can use it for energy, so you burn it. That's good to do that.

Holly Wyatt: So you eat it, and then you get rid of it by burning it?

Jim Hill: You eat it and it fuels your metabolism. And a great example there are athletes, and we'll come back to athletes. They burn a lot of carbohydrates. So you can burn it. Number two, you can store it. Now, our bodies have almost an unlimited amount of space to store fat, not so with carbohydrates. You store it in the form of glycogen, you can put a little bit in your muscles and livers and bloodstream, but you can't store very much of it. So what happens when you eat more carbohydrates than you burn? You fill up your glycogen stores. That doesn't take very long. And then the excess can be converted to fat. So if you're overeating carbohydrates, you can end up storing excess energy as fat.

Holly Wyatt: Oh, I think that's important because I know sometimes we hear that you can't take carbohydrates and store fat. You know, that's one of those iffy things. So talk a little bit more about that. How could you overeat carbohydrates? And maybe we should even say, what is carbohydrate? You know, just to make sure people know. What is carbohydrate? It's like, what do we conclude? Sugar, bread, crackers?

Jim Hill: Vegetables have a lot of carbohydrates, whole grains, these sorts of things. We'll talk in a minute. They're sort of good and bad carbohydrates. And thinking about how much carbohydrate you should eat, we're also going to have you think a little about what types.

Holly Wyatt: So let's say you eat too much rice. You eat a lot of rice. That's a carbohydrate. Can that be stored as fat?

Jim Hill: Absolutely. Again, it's not the most efficient thing. Your body is very efficient at storing excess fat as fat. It's not very efficient at storing excess carbohydrates as fat. But if you have excess, you have to do something with it. When you burn as much as you can and store it as much as you can, the only path left to your body is to convert it to fat.

Holly Wyatt: Either convert it to fat or store any fat that you eat. That's kind of how I think of it. Sometimes there's kind of two ways you could do that, right? It'll burn the carb. But then if you've eaten any fat, it'll go ahead and store that fat potentially.

Jim Hill: But the idea is anything you overeat is going to lead to excess fat storage. Now overeating carbohydrates - you're not going to store the excess as efficiently as overeating fat, but you are going to store it. So the question (and you hit on the right question) is how much do you burn? If you burn all the carbohydrates, no problem. Right? You have no problem with that. Here's the problem, Holly, one of the things that cause you to burn carbohydrates is movement or physical activity. Again, athletes, are taking in huge amounts of carbohydrates, but they're burning huge amounts of carbohydrates in physical activity. In a sedentary society, the amount of carbohydrates you need is lower, so it's easier to have an excess of carbohydrates. Again, you know me, we can't get away from physical activity. The diet's important, but physical activity's important too. If you're an athlete, if you're physically fit - carbohydrate in most cases is not an issue for you. If you're overweight, sedentary, or not moving very much - it's easy to overeat carbohydrates and that is going to result in weight gain.

Holly Wyatt: So let's make sure we understand this right here. So basically, if you're moving a lot, if you're spending energy…and we say athlete, but I don't know that you have to be like a true what people maybe think as an athlete. But if you're out there moving, and you're getting in your steps and your lifestyle activity counts and everything; you're just not sedentary sitting all day. If you're moving, then you burn some of that carbohydrate and you can then theory, I think, eat some of that carbohydrate and not have to worry about it getting stored as body fat. Is that fair?

Jim Hill: To put simply, if you have excess carbohydrates in your diet right now, you have two strategies. You can reduce your carbohydrate intake or you can increase your physical activity.

Holly Wyatt: So people who aren't moving, reducing that carbohydrate intake, which would reduce their overall intake, that might work pretty well.

Jim Hill: We know it works well in the short term because low carbohydrate diets work. You and I've researched this. We've compared low carbohydrate to other forms of diets. And, if you restrict carbohydrates, you can lose weight. And when you lose weight, it has a very positive effect on metabolic health.

Holly Wyatt: So sounds like that's that's one possibility, right? One possibility is to do that.

Jim Hill: I think it's why low-carb diets are so popular. They're one way of losing weight. But the problem is, what we see, and I think what the data suggests is not a lot of people can stay with these over the long term. They're great for a while, and they're great for weight loss but people like carbohydrates. It's hard over time to restrict carbohydrates. If you do it, it works. It's hard to do it over the long term.

Holly Wyatt: If you were a person that you did it and you felt good and you just don't like carbohydrates, then it might be it might be a longer-term solution. I mean, any diet is hard to adhere to long term, not just a low-carb diet. It's just, you know, we have that problem.

Jim Hill: Before we did the research, I was very skeptical. I thought, this may not be a great diet to lose weight, but you know what? We and others now have shown it's a perfectly fine way to lose weight.

Holly Wyatt: I followed a low-carbohydrate diet for most of my time in medical school and residency. But then when I started to kind of pick up my activity, I changed things. But I did it for some time. But as you said, when you want some carbohydrates, there's a problem because you can't have them. I did want to have some of the things that are carbohydrates in my diet, which brings me to the conclusion that all carbohydrates are equal. Do I have to cut out all my carbs or could I look at just the sugars? Sometimes they say, “OK, let you don't have to cut out the grains and the complex carbs.” What about sugar? Is it different?

Jim Hill: The way we classify carbohydrates is very complex. We are used to the old way where there were simple and there were complex. But, if you look at it, the kinds of carbohydrates that bring other nutrients are vegetables whole grains, and so forth. Because you get calories, but you also get vitamins and minerals. Contrast that with sugar and some of the other carbohydrates. Same number of calories coming in, but you don't get the other stuff with it. You don't get the vitamins and minerals, etc. So, again, I'm not of the mindset that sugars are the total enemy here. But if you want to cut out carbohydrates, sugar is a good place to start. Because you're simply getting calories to not a lot of nutrients with it. So I do think as you're thinking about cutting your carbs, thinking about which kinds of carbohydrates you may want to cut out first.

Holly Wyatt: I agree that the sugar sometimes, like you said, don't bring anything with them. And sometimes it's easy to kind of consume a lot, especially beverages. I always think about sugars like in soda and those energy drinks and, sweet tea. We're here in Alabama, so sweet tea has a lot of sugar. So that's something maybe is a way, a specific type of carbohydrate you could try to eat less of. So why do you think it's so easy to overeat sugar, to overeat carbs?

Jim Hill: Because it tastes good. Again, a lot of our food intake is driven by taste. So if you look at the things that add taste to foods - it's sugar, fat, and salt. And so when you get those in the right combination, it's you can't resist it. But we enjoy those. We enjoy those. You think of them as treats. They're the kinds of foods that taste good. And that's part of the problem they do taste good. So it's hard over the long term. It's people are pretty good in the short term at restricting carbohydrates. But we have had low carbohydrate diets around for a long, long time. And if that were the only solution, we would have seen an impact on obesity rates. It's not the only solution. And one of the things we'll come back and talk about maybe later here, in our new episode is it's OK to lose weight on one kind of diet, but to keep weight off on another kind. I am convinced that losing weight on a low-carb diet is perfectly fine. You're going to improve your health. You're going to lose weight. I'm a little bit more skeptical about whether very many people can maintain that over the long term.

Holly Wyatt: I agree. I think it's hard to eat a low-carbohydrate diet for long periods for some of the things that we've talked about. But, you know, I always say, and yet these diets remain very, very popular. Why do you think that's the case? I mean, they're not going away. We've been doing low-carb diets for a very, very long time.

Jim Hill: They don't go away because they work for weight loss. And again, you and I talk about this all the time. People focus on getting the weight off. The hard part is keeping it off. But that's not where people want to focus. And low carb diets are a very good way, not the only way, but a very good way to get the weight off. That's why they're popular and you find people that do them over and over. I'm going back to a low-carb diet because it worked before. Well, if you have to go back to it, it probably didn't work before.

Holly Wyatt: And I think you get some rapid weight loss at the beginning with a low-carb diet. Because you pull out that glycogen (we talked about where you can store some of that carbohydrate and with that you get a big water weight loss), we don't care as much about water as we do about fat. But you see it on the scale. You see those pounds coming off really, really quickly. And I think that kind of motivates you to feel like you're successful. And when you feel like you're successful, you continue it. So I agree. And I think the idea is you do need to think about what diet you use for weight loss and then what you can do long term. What diet can you adhere to for weight loss maintenance? So that brings us to the second question (or really kind of we were even thinking about these as kind of diet myths, Jim), are fats good for you? I hear on social media all the time that you need to eat more fat to lose weight. I mean, they literally show that. They say cutting fat is not the best way to lose weight. They even say sometimes it causes you to not burn fat. And they always show this bacon and eggs sizzling in a skillet saying, this is what you need to eat to lose weight. And everybody's got it all wrong. So what do you think about that? Are fats good for you? Should you use fats? Should you eat fat to be able to lose weight?

Jim Hill: So let's start with what we know about the science. We don't know everything. And again, in the 70s and 80s, all the advice, government advice, scientific societies saying eat low fat - that's the way to lose fat, to lose weight, and be healthy. Clinical studies show that when people follow a low-fat diet, they can lose weight on the low-fat diet. And you and I have compared the low-fat diet to the low-carb diet. Several other studies have done that. The bottom line is that I am convinced that both diets work equally effectively. Now, here's the interesting thing about each of those diets, some people do well, and some people don't. So it may be that one of these days we'll be able to predict, Holly, this diet is best for you for weight loss. But the science suggests that low fat does help in keeping weight off. Now, you need fat. You need fat to be healthy, but you don't need that much of it.

Holly Wyatt: So, I got a question though, Jim, because I can remember back a long time ago, we've got on a big low-fat kick and we took fat out a lot of foods. Low fat was everywhere and we still gained weight, right? We didn't solve the problem. So what was that about? I think a lot of people say, see that shit that didn't work. That's why a lot of people say that, oh, you should need the fat.

Jim Hill: People point to it as not working, but let's look at what happened. A lot of people call this the snack well phenomenon. Remember snack wells? They were low-fat cookies. And so…

Holly Wyatt: It tasted really good.

Jim Hill: You eat the whole pack.

Holly Wyatt: You're right. There was no fat so I could eat the whole box. That's what...

Jim Hill: So here's the problem with how people interpret nutrition messages. So the message, and it was everywhere, eat low fat. That was the message.

Holly Wyatt: It got out there. It was really good that everybody knew that.

Jim Hill: And the food industry to go along with that, said, “Okay, the government's saying eat low fat. Let's make low fat product.” To make low-fat products taste good, what must you put in them?

Holly Wyatt: Sugar, salt.

Jim Hill: Sugar, carbohydrate. So Snack Wells was a cookie that was low in fat but high in carbohydrates. So if you look at the available data, you know I'm not a big fan of self-reported food intake, but what seems to have happened in the efforts to reduce fat, is fat didn't go down in terms of the amount we're eating. What happened is we started eating more carbohydrates and overeating contributing to weight gain. So I don't think it's fair to say low fat doesn't work because I don't think as a society we've tried that. So I think number one, reducing carbs or reducing fat will produce weight loss in the short term. What we need to help people think about is once you lose weight, what's the right combination of fat and carbohydrate?

Holly Wyatt: And it sounds like when we did that (when we were trying to reduce fat), we didn't concentrate on reducing calories. And that to me is the key. That's the learning. I don't think it was purposeful. I don't think there's any conspiracy theory here. I think we didn't understand it fully. And the idea is the way to reduce calories, what we thought was to reduce fat. But if you didn't do that, if you put in additional calories instead of pulling the calories out, it didn't work. Which I guess kind of makes sense now, but I think then we didn't fully appreciate that quite as much.

Jim Hill: That's one thing that we've consistently found in the National Weight Control Registry; our registry where we follow successful people. They generally follow a low-fat diet, not super low fat, but a low-fat diet. But they also are mindful of calories. So those two things together, if you're simply reducing fat and not paying attention to calories, that's not good. You've got to do both. But the same thing on carbohydrates. It's not fat or carb alone. It's fat and carb in combination with total calories.

Holly Wyatt: So what about different types of fat? We talked about different types of carbohydrates. There are different types of fat. What about healthy fats? Can you eat as much of those as you want? What does that mean?

Jim Hill: So number one, fats contain more energy than carbohydrates. So carbohydrate has four energies per gram. Four calories per gram while fat has nine calories per gram. Two and a half times more. So you have to be mindful that if you're eating fat, you're taking in more calories. And there's no kind of fat that you can eat unlimited amounts of. Now some fats are thought to be better and worse. You hear a lot about monounsaturated fats and olive oil, right? The Mediterranean diet, a lot of these healthy diets say to eat olive oil. And if you're going to choose your fat, olive oil is monounsaturated, a pretty good choice. But again, you can't eat unlimited amounts of them. The other two kinds of fat are unsaturated fat and saturated fat. And in general, the advice to people is to avoid saturated fat. And that's basically animal fats. Unsaturated fats are vegetable-based fats. So the advice right now is to limit saturated fats. Of the fats you eat, make them more monounsaturated and highly unsaturated.

Holly Wyatt: And I think the key with that, Jim is a lot of that message is: the good fats may have some protective or helpful for your heart health and the bad fats may not, right? Might cause cardiovascular disease. But when it comes to calories and when it comes to body weight, that's where I think the message gets confused because we hear good fats, and it may be good for your heart, right? Of all the fats, that may be the best one for your cardiovascular system, for your brain. There may be some positive in that. And then saturated fat might be on the negative side, but that's not necessarily talking about weight loss.

Jim Hill: That's right. People are saying, I want to eat as much unsaturated fat as I can. That's a recipe for obesity. Calories count. What you want to do is decide what your fat limit is going to be and of those fats, the majority should come from polyunsaturated and monounsaturated.

Holly Wyatt: This is such an important topic, I think because people don't get it. If you ate, let's say, 100 calories of good fat and 100 calories of saturated, what we're considering a bad fat, right? Not a non-healthy fat. Would the body see the many differences in terms of body weight regulation, in terms of weight loss, and weight loss maintenance? Now specifically, are they different in terms of the calories?

Jim Hill: Doesn't seem to be different there. They may have different effects on health. So they may have different effects on cholesterol and other sorts of things. But let's put it another way. If you overeat 100 calories of olive oil and overeat 100 calories of lard, it's going to lead to the same increase in weight in the body.

Holly Wyatt: There. That's the message I think we want to get out that's really confusing for some people. Because they think that, oh, olive oil, I can put it on as much as I want. It's good for me. It's not going to hurt. They just feel like it's a free-flowing fat that they can do no wrong with. And I think that's important.

Jim Hill: There’s no free nutrient that you can overeat and not suffer weight gain from it. Anything is ultimately going to be stored. You're going to store fat if you overeat it.

Holly Wyatt: And once again, just like the carbohydrate story, if you do go on a low-fat diet to try to reduce weight if you reduce your fat and reduce your calories, you will lose some weight. But if you end up pulling the fat out but substituting something else, you're not going to lose weight, which I think is critical.

Jim Hill: The last thing on fat, and I'm just going to put it in a teaser for a future episode, is we spent decades getting people to switch from full-fat dairy to low-fat dairy. And there's a real controversy in the scientific field about whether full-fat dairy might be better than low-fat dairy. This is totally unclear at this point, but it's fun. There's a lot of research that's coming through. Dairy has saturated fat, but research suggests it may not act like other kinds of saturated fat. So we're not going to talk about that now.

Holly Wyatt: So that's something we may not know.

Jim Hill: We don't know. Do not go out and say, get rid of your low-fat right now. But stay tuned. That's an interesting scientific question that's being evaluated.

Holly Wyatt: We think we know stuff, but we learn new things, and it's constantly changing. It's constantly evolving. So I think low-fat diets remain popular too.

Jim Hill: Well, in the National Weight Control Registry, still the majority of people are using low-fat diets. Some are using low-carb, but the majority are still using low-fat.

Holly Wyatt: I think that for some people, once again, it's very individual, a low-fat diet long-term may be a little bit easier to do than a low-carbohydrate

Jim Hill: But let's be clear, Holly. We talked about the problems in maintaining a low-carb diet and the same problems in adhering to a low-fat diet. So we can't criticize carbs because it's hard to adhere to either one.

Holly Wyatt: It is hard to adhere to either one.

Jim Hill: So let's get some concrete advice here. How much carbohydrate should you take in? Here's what the dietary guidelines recommend. And they give you a wide range. They recommend 45% to 60% of your calories come from carbohydrates. That's a wide range. So what I would say is if you're physically active, you want to be on the higher end of that. If you're sedentary, you may want to be on the lower end of that. If you’re a regular exerciser, I recommend that 50% to 60% of your caloric intake should come from carbohydrates, as they are efficiently burned during physical activity. Now, on fat, the dietary recommendations, again, are a wide range, 20% to 35% fat. I sense that 35% is too high. People in the National Weight Control Registry report less than 30%.

Holly Wyatt: Now, that's self-reported. So we know it's probably higher than 30%.

Jim Hill: I think a 20% fat diet, if you could follow it, it would be great. But it's hard to do that. And physical activity plays a role here too because physical activity burns carbohydrates and fat. So again, if you're sedentary and overweight, you may want to be toward the lower end of that. 20 is difficult. 35, I think, is pretty high. So you may want to think about being somewhere in the mid-range there.

Holly Wyatt: So if you are active, you can eat more calories, and you can eat a little bit more carb and you can eat a little bit more fat, which makes sense.

Jim Hill: We will delve deeply into that topic because both of us have observed over time that maintaining weight loss without physical activity is incredibly challenging. Physical activity does so much - it burns carbs, it burns fat, and it burns calories.

Holly Wyatt: And it does a bunch of other stuff that we think can help out. But, okay. So, Jim, what do you eat? You eat a low carb, do you eat low fat? What do you eat and why do you eat it?

Jim Hill: I start with being active. I try to get at least an hour a day of intentional physical activity, and then I try to incorporate movement throughout the day. So I don't limit carbohydrates. I like carbohydrates. I try to eliminate the simple stuff. So I rarely consume a sweetened beverage. So again, that's an easy one, I think, to give up. So for me, I'm not following a low-fat diet, but I try to watch high-fat foods. I like to be physically active. And my carbohydrate intake is probably above 50%. How about you?

Holly Wyatt: So, you know, I struggle with my weight. So I'm constantly thinking about my diet in terms of either, do I need to lose a few pounds. If I gained a few pounds, therefore I'm in a weight loss mode, or am I maintaining? And it kind of changes for me. When trying to lose weight, if I gain a few pounds or need to reach my summer weight, I need to be in a negative energy balance and control my appetite. To achieve this, I will reduce my carbohydrate intake. That's what tends to work for me, but I'm going to do it for a very finite period, meaning for a certain length that I need to lose weight. So I tend to go low carb because I can adhere to it for a short period. It gets me in that negative energy balance where I burn fat, meaning I'm not eating a lot of calories and I can be still kind of satisfied. So I do that. But one of the things I do when I go low carb is I don't go low vegetable. I keep a lot of vegetables. So that's where I'm going to get my carbohydrate source from vegetables because I need volume. So it's low carb, but I'm pulling out more like the sugars and not the vegetables and not the high fiber type carbohydrates. And then when I'm in maintenance, and my activity is high, or if I'm kind of doing, I do some runs in some, some 5Ks and 10Ks. That's when I put back in the carbohydrates and I just maintain my weight with that additional carbohydrate. I'm pretty low fat the whole time through.

Jim Hill: So basically what we're telling people, you can lose weight by reducing carbohydrates. You can reduce weight by lowering fat. Both those are difficult in the long run. So after you lose the weight, and we've talked before Holly about looking at a 3 to 6-month period for weight loss, if you're on low carb, you're probably going to need to increase those carbs. The way to do that without gaining weight is physical activity. Same way with low fat. If you're following low fat for a while and then you lose the weight, you're probably going to need to increase fat a little bit focusing on healthy fats and increasing physical activity. And it comes back to if you want to increase your fat and carbohydrate intake, you've got to increase your total calorie expenditure, which means you've got to move more. But either of these works. I think it's a mistake to say carbs are bad, and fats are good. It totally depends. And what you've got to do is find that opposition that works for you. It may be different during weight loss than keeping weight off.

Holly Wyatt: I agree. And like you said, that individual piece, what works for you, and that's allowing people to kind of figure that out. You've got to kind of do a little bit of your research and figure out what works for you in those different situations.

Jim Hill: There's a whole effort in the nutrition field called precision nutrition to identify how to determine the right diet for you. But we're still a long way off from doing that. And right now it's a little bit about trial and error. But I think what we know is it's not one size fits all. Some people are going to do better on one form of diet than the other. Eventually, science will help us figure out who that is. But right now experiment a little bit, choose your diet - low fat, low-carb, lose the weight, and then play around with how you add carb and fat back in to keep weight off. But you've got to move.

Holly Wyatt: So pie in the plate activity, you've got to move. But here's the other kind of pie in the plate I want people to think about - it's okay to lose weight on one type of diet and then to keep it off with another. I think sometimes we think, well, whatever we're doing to lose weight, you've got to do it forever. No, it's okay. This diet could be the best one for you to get some weight off. And this other diet, low fat, low carb, may be the best diet to keep it off. And then you add that physical activity in and that's when you can play around with it and figure out what works best for you.

Jim Hill: Holly, I have an exciting plan for a future episode where we will delve into our findings from the National Weight Control Registry. One thing we learned is there was no similarity in how these people lost weight. They lost weight on every diet imaginable. But when we look at how they're keeping it off, we begin to find some things in common. And we'll tell you about that in one of our future episodes.

Holly Wyatt: Yes, that'll be a good one.

Jim Hill: So that's it. Wow. This was some complex stuff. And I hope we simplified it for people, but there's no good or bad type of food. Carbs aren't good or bad. Fats aren't good or bad. It's finding the right combo that works for you.

Holly Wyatt: I agree.

Jim Hill: So, Jim and Holly signing out. We'll talk to you next time.

Holly Wyatt: Bye, everybody.

Jim Hill: And that's a wrap for today's episode of “Weight Loss And…”, we hope you enjoy diving into the world of weight loss with us.

Holly Wyatt: If you want to stay connected and continue exploring the “Ands” of weight loss, be sure to follow our podcast on your favorite platform.

Jim Hill: We'd also love to hear from you. Share your thoughts, questions, or topic suggestions by reaching out at [weightlossand.com](http://weightlossand.com/). Your feedback helps us tailor future episodes to your needs.

Holly Wyatt: And remember, the journey doesn't end here. Keep applying the knowledge and strategies you've learned and embrace the power of the “And” in your own weight loss journey.