31: Scientists have proven that "diet foods" trick you into eating MORE

Jenna
 0:00:00
 Hello, this is No Wellness Wankery Podcast. My name is Jenna D’Apice and I'm joined by my co-host, Wendy Cohen. 

Lyndi
 0:00:43

Hi, I'm a nutritionist, dietitian. You might know me as The Nude Nutritionist. And today, I want to talk about a piece of research that is super interesting. And it's not new.

Lyndi
 0:00:44
 So this piece of research was done in 2011 and it's called the milkshake study. Well that's kind of like the colloquial term given to it but it's super interesting. Yeah I saw it written on the piece of paper and this is why I was so intrigued to talk about it because everyone I saw the milkshake experiment I was like what's that? It sounds interesting. I love milkshake. Okay so this is really cool research done by a clinical psychologist from Columbia Business School, which is in New York. Her name is Alia Crum, and she's done so much cool research. Oh my goodness. But I think this is the most interesting study, I think. So what she did is she was kind of testing the theory being like, okay, how we feel about a food and how it's labeled, does that change how our body actually responds to that food? And the milkshake experiment kind of showed us that, yeah, it does. Here's what she did. She created this big batch of milkshake and the milkshake was a French vanilla flavor and it was 300 calories. She split that batch into two. In the one batch, she put it into a container and she called it the Sensi Shake, a fat-free, guilt-free, 104 calorie milkshake. And remembering, this is a 300 calorie milkshake. On the other batch she separated, she put it into a container that was the Indulgence. The Indulgence milkshake, people were told it's decadence you deserve, and they were told that it was 620 calories.

7
 0:02:22
 But it's the same milkshake.

Lyndi
 0:02:23
 Same milkshake, and so she gave it to these different study participants, and what they were measuring was ghrelin. Now, ghrelin is colloquially known in medical terms as the hunger hormone, right? So when we get hungry, you're going to have higher levels of ghrelin. That's the thing that sends messages to your brain to say, it's time to eat. And as you eat and get satisfied, ghrelin levels should decrease and leptin, which is a satisfaction hormone, should increase, okay? Okay, yeah. So what she's measuring is how much of this hunger hormone is still circulating in your body after you have these milkshakes. Is it different? Because just because people thought they were different milkshakes. The other thing to know about ghrelin is it also regulates your metabolism. So as long as you've got high levels of ghrelin, so you feel hungry all the time, your body actually slows your metabolism because it's like, well, what if we don't get food? We need to actually have a slowed metabolism in case there's like a little bit of a famine. And so higher levels of ghrelin means a little bit more of a slowed metabolism. Okay, so there's benefit in having lower levels of ghrelin, right? What was really interesting about this is these study participants, after they had it, they measured their ghrelin and they found that those who had the indulgence, the high, supposedly the decadence, 620-calorie smoothie, their ghrelin levels reduced three times more than those who thought they were having the diet smoothie. It was a much steeper decline in ghrelin and it happened really a whole lot more quickly. And that's simply because they thought this was more indulgent, whereas the others who had this diet thing, the diet smoothie, they felt as though they hadn't had as many calories. Their ghrelin response was much slower, so they had much higher levels of ghrelin simply because they did not think it was as satisfying based on the description that they were given.

2
 0:04:09
 This is insane.

Lyndi
 0:04:12
 What this says to me is our relationship with food matters. It matters a whole lot. The belief system you have around the food you are eating, why you are eating it, really does matter. It pinpoints this whole issue we had with the low-fat era and how awful that was because we were being told, okay you can eat this much of this like low sugar, give you these low sugar lollies. You're like, well I can eat a whole packet of low sugar lollies and you don't ever feel satisfied by doing something like that because as we can see physiologically how you feel about that food, your body is changing in response to it.

2
 0:04:51
 This is blowing my mind.

Lyndi
 0:04:52
 So no one was like, the milkshakes taste the same because they'd been told. Well I don't think they were given the same milkshakes. Yes, okay. They were kind of split off into two groups, but there was enough of a sample size and it was a double-blind placebo kind of trial, so it's interesting. So would you say this is like when we have foods that we've labeled good or bad, yes, this is what's happening. So, you know, in previous podcast episodes, we've talked about the fact of, you know, people ask me, should I only go for low fat, or why do you recommend full fat? I feel like when you eat the food that you really enjoy, that you find most satisfying, that is right for you, physiologically, you're gonna have a better response to it. So, for some people, it might be a medium fat. For some people, it's going to be a full fat option. But I think there is real benefit in that because when you, for example, have that full fat option, there is research to say you do feel more satisfied as a result of it. Plus, there's the mental aspect of this is something that has got high energy. It's going to give me more. It's going to make me feel more satisfied. Therefore, I naturally need less of it. And I don't think what we can see from here, this isn't like people trying to curb themselves. They're not like, oh this is high fat I should only have less. This is on a physiological level that we're getting these changes. I think what happens is when we have these low-fat diet foods, I don't know about you, but I used to get like those like diet jelly. I could eat like a whole bowl. The limit does not exist. The limit does not exist. Or those like diet mousse, chocolate mousses. How many of those could I eat in one sitting? Especially when I was binge eating. I used to do this thing where I'd find all these diet foods that I could somehow binge on. Have you seen those Halo ice cream? It's those tubs, whole tub, but you could do it. It's 320 calories or whatever. The whole tub. The whole tub. I'm like, you're just setting yourself for an unsatisfying binge just by that perception of how it's being marketed to you. And it tastes crap.

8
 0:06:49
 It tastes terrible.

4
 0:06:50
 So bad.

5
 0:06:51
 And they're basically saying the thing, you can eat this whole tub.

Lyndi
 0:06:53
 Yes, that is it. It's permissibility to eat something that's not even that enjoyable anyway. And there is that book, Why French Women Don't Get Fat, that was kind of like really big. Don't like it in many ways. What I found interesting is around the time that that book was popular, I did exchange to France. I was 16 years old, deep in my eating disorder days and I was just fascinated to learn how the French would eat and how it would be so different to how I'd eat my diet food back in Australia. And they ate a lot more indulgent food. So they would have raclette for dinner, which is like potato and melted cheese and cream. And that was it. And I remember my French mother bringing out this dish and it looked so small. We're like a family of five or five of us, six of us. And I was like, that's not nearly enough food to feed us all. But once she put it on my plate and I was like, oh, I need more. But then I started eating it and I finished that meal feeling really satisfied. It was awesome. It was so tasty. It really hit the spot. And this is the whole like French idea, is like having something that is really satisfying, allows your body to change its hormonal response in terms of ghrelin and leptin levels, helping you feel more satisfied.

7
 0:08:06
 And tell yourself that you're satisfied.

Lyndi
 0:08:08
 Yeah, I've eaten, and not only was I eating, or was I eating and I'm physically full, I'm emotionally satisfied. These are two components that we need to be ticking, and I think sometimes the nutrition world is obsessed with making sure that we are sat, that we're like physically full, but we're missing out on the satisfaction factor. And we need to make sure that we're ticking the boxes. When it comes to that, they did this, they called like the satiety index, which was a study I think in 1995, where they looked at how satisfying certain foods were. And what's really interesting is a lot of these foods that are really satisfying are foods that diet culture has told us we're not allowed to have. So things like potatoes, bread, pasta, yogurts, like we find these foods really satisfying and we're like told that we're not allowed to eat them. But if taking out all these satisfying foods from our diet means that we're suddenly looking for all these other shortcuts, it can make us feel like we're constantly eating because we're never truly feeling satisfied by anything we're eating. And do you think that also makes us constantly thinking about food? Constantly. It's like the whole almond thing. You're like, oh, I'm allowed 12 almonds and then 600 almonds less.

7
 0:09:13
 You're like, they want more.

Lyndi
 0:09:14
 Damn, they did not hit the spot because it wasn't emotionally satisfying and it probably wasn't physically satisfying either because I didn't think almonds are on the satiety index. They didn't rank very highly. Or maybe they do. Nuts are pretty satisfying. Anyway, what I just think is really interesting is I had this question from one of you who wrote to me and you said, loving the podcast. Thank you. I appreciate that. Although, she said, sometimes I feel like I end up feeling more confused since the advice that I give on this podcast is completely opposite to another nutrition podcast that I listen to. Just an example, I love that you say to eat full fat cheese and milk or low fat depending on taste preference, but I listen to another podcast and I'm being told to eat low fat cheese. How do you deal with this different professional opinion? I think this is such a great question. So there is going to be research on either side that is going to endorse low-fat or full-fat. It depends on where you're going to look. Pretty much with everything in nutrition, nothing is black and white and you can find certain groups that are going... You can find research that's going to endorse what you think and refute what else you think. Everything is still theories at this point. If you think about nutrition as a profession, it's incredibly young. It's not even 100 years old. That is as fresh as a profession can get. I can't think of any, apart from influencers sadly, I can't think of many other professions that are quite as fresh as that. And you think about, well, how much research has really been able to be accomplished during that time. We're now going through a nutrition boom. The evidence is still very much emerging. What I will always tell you is to listen to your body first and foremost. And if you ever listen to other advice that you're like, I don't know if that's gonna work for me, whether I said it or someone else said it, listen to your body first. I can't give you anything else more concrete than that. That almost the way I see nutrition is you have to run these tiny experiments. So you might go, okay, well, how do I feel by having the full fat yogas, and you might try that for a week, and the next week you have the low fat. And fundamentally, the one that makes you feel best, whether it's satisfaction, the way that it makes you feel, that's gonna be the best thing for you, because you're not gonna do a study where it's looking at your ghrelin levels.

6
 0:11:27
 You know, that's not gonna happen.

Lyndi
 0:11:30
 I can't offer you that, sadly, although that would be ideal. That would be the ideal way to get to the bottom of what you need. So if there's anyone who's giving concrete advice saying, this is the way you should eat, that's nonsense. There's no one diet for everyone. And that's why I give yes, more vague advice and fundamentally asking you to respond to your body before anything else. And this milkshake experiment is a perfect example of that. How buying into like, just because something is technically correct doesn't mean it's right. Okay? So, like having the perfect nutrients doesn't give you the perfect diet because if you're just looking at, if you are a robot, like I could tell you what to eat, but you're not. You're a human who's got psychological needs. And I think what I do, what I'm proud of what I do is I bring in the psychology of eating and mix it in with the physiology of eating. And I think that is what is so often missed when you listen to these other nutrition podcasts. They could go, this is what you technically should be doing if you lived in a foreign world where you had zero preferences for food or zero beliefs around food. But as we can see from this study, mindset matters and it can override our physiological responses because of the certain beliefs we have around food. And this means that the way that food is labeled to us, the overabundance of nutritionism and all the health claims that we get bombarded with, all the things we get told, this is all influencing our perception and our mindset around food. And I almost think that unsubscribing from a lot of that stuff, reducing the load of nutritionism in your brain is really precious, because that allows you more headspace to go what makes me feel good, and remembering the basics, like yes, eat more whole foods, cook at home more, do things that make your body feel good, and then just find what works for you within that space.

5
 0:13:18
 I love this.

7
 0:13:19
 I love this episode and listening to you.

6
 0:13:21
 Oh my gosh.

Lyndi
 0:13:22
 It's a goodie, huh?

5
 0:13:23
 It's really good.

2
 0:13:24
 I think sometimes you're like,

Lyndi
 0:13:25
 oh yeah, don't call foods good or bad, and it's just all these airy concepts,

2
 0:13:28
 but it's like, this shows like it actually matters.

Lyndi
 0:13:31
 It really does matter, and I think, listen, I haven't seen this being applied to other examples yet, but I'm sure there's some really cool stuff happening. This really amplifies this whole idea of the placebo effect, right? So this is what we know, that every single drug that you take is going to have a placebo effect because when we believe something's going to have a certain outcome, we almost can will it with our mindsets. I think that's just really important to recognize the power of the brain. is we eat with our brains as much as we do with our mouths and our digestion. And I think as a whole, a lot of people are getting really excited about the gut-brain axis and how interrelated what we eat is affects our mental health, and it goes the other way as well. How you feel about food affects the food you eat, and what you eat affects your brain.

4
 0:14:20
 Wow, cool guys.

Lyndi
 0:14:21
 All right, well I hope this was interesting to you. I certainly find it interesting. And if it is, I can bring more kind of cool research.

3
 0:14:26
 Yes, I'd love to.

2
 0:14:27
 Bring more.

3
 0:14:28
 Okay, cool.

Lyndi
 0:14:29
 We'll do more. We'll do more. And of course, if you find any cool studies that you want to share with the group, please message me and we can break it down and talk about it together on the podcast. DM me at newdove.nutritionist, ask me any questions. Leave us a review. I'd love it. Jenna would love it.

2
 0:14:45
 We love reading them.

Lyndi
 0:14:46
 Thank you. And thanks for listening. Bye! Do you feel like you know what you should be eating but like you feel completely out of control with food? You're either eating perfectly or you're face planting into the fridge? Well if you've got binge eating or you're struggling with emotional eating I can help. Check out my program Keep It Real. I've got lots I can teach you and hey you don't have to be a binge eater for the rest of your life. You can get 20% off Keep It Real when you use the code podcast when you check out via the website and because I don't want this to be just another failed attempt for you, I'm offering a 30-day money back guarantee because you know what? You've just got to give these things a go, no risk. You've just got to give these things a go, no risk. Give it a try.