Episode 510: Layne Norton, PhD: The Best Diet to Follow + Is Diet Coke Actually Bad For You

Ever wondered which diet actually works? Or if artificial sweeteners are as dangerous as the internet makes them sound? In this Fitness Friday episode, I sat down with nutrition expert Dr. Layne Norton to cut through the diet noise. We break down why personalization beats every trend, what the research really says about diet soda and sweeteners, and why the "best diet" looks different for every person. If you want straight answers, not fear-based headlines, this conversation will challenge a lot of what you think you know. Dr. Layne Norton is the founder of BioLayne, a company built on science-driven coaching and real-world experience. He has coached more than 70 athletes to pro status and helped thousands rethink nutrition with evidence instead of hype. Layne holds a BS in Biochemistry and a PhD in Nutritional Sciences, where he trained under one of the leading researchers in protein metabolism. What We Discuss: (00:00) The truth about the best diet for weight loss (00:38) Why adherence drives long-term results (03:29) How to find the diet style you can actually sustain (06:56) Diet soda and real weight-loss evidence (08:25) Artificial sweeteners and gut health research (10:41) What aspartame really breaks down into Thank you to our sponsors: Therasage: Head over to therasage.com http://therasage.com/ and use code Be Bold for 15% off Air Doctor: Go to airdoctorpro.com http://airdoctorpro.com/ and use promo code HUSTLE40 for up to $300 off and a 3-year warranty on air purifiers. Magic Mind: Head over to www http://www/.magicmind.com http://magicmind.com//jen and use code Jen at checkout. Momentous: Shop this link https://www.livemomentous.com/?srsltid=AfmBOorDUIZz3psr1Qsq_n1yE8_6JTq_QUFabOO9lH65HDEXCIoJOPLj and use code Jen for 20% off Manna Vitality: Visit mannavitality.com and use code JENNIFER20 for 20% off your order Prolon: Get 30% off sitewide plus a $40 bonus gift when you subscribe to their 5-Day Program! Just visit https://prolonlife.com/JENNIFERCOHEN and use code JENNIFERCOHEN to claim your discount and your bonus gift. Amp fit is the perfect balance of tech and training, designed for people who do it all and still want to feel strong doing it. Check it out at joinamp.com/jen https://www.joinamp.com/?utm_source=podcast&utm_medium=in-stream&utm_campaign=jen Find more from Jen: Website: www.jennifercohen.com https://www.jennifercohen.com/ Instagram: @therealjencohen https://www.instagram.com/therealjencohen/ Books: www.jennifercohen.com/books https://www.jennifercohen.com/books Speaking: www.jennifercohen.com/speaking-engagement https://www.jennifercohen.com/speaking-engagement Find more from Layne Norton, PhD: Website: www.biolayne.com https://biolayne.com/ Instagram: @biolayne https://www.instagram.com/biolayne/

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Speaker 00

  Hi guys, this is Tony Robbins. You're listening to Habits and Hustle. Crush it!

• 0:06Jen Cohen?

  Hey friends, you're listening to Fitness Friday on the Habits and Hustle Podcast, where myself and my friends share quick and very actionable advice for you becoming your healthiest self. So stay tuned and let me know how you leveled up.

• 0:28Jen Cohen?

  Before we dive into today's episode, I want to thank our sponsor Momentous. When your goal is health span, living better and longer, there are very few non-negotiables. One of them, quality. And when it comes to supplements designed for high performers, nobody does it better than Momentous. Momentus goes all in on NSF certification, which means every single batch is tested for heavy metals, harmful additives, and label accuracy. And that's why they're trusted by all 32 NFL teams and top collegiate sports dietitians across the country. Here's the thing, they don't sell every supplement under the sun,

• 1:11Jen Cohen?

  because they believe in nailing the basics with rock solid consistency, and those basics are protein and creatine. Momentus sources Creapure, the purest form of creatine monohydrate available, an absolute must for both men and women who want peak physical and cognitive performance. So if you're serious about leveling up, go to livemomentous.com and use code GEN for 20% off. Just act now. Start today. GEN for 20% off. livemomentous.com.

• 1:54Speaker 02

  Now, if we look at, does one diet stand out as better than the others? So there's two studies I'm thinking of. There was one looking at four different diets and one looking at 14 different diets. Both were systematic reviews and they looked at long-term weight loss. And what they found was basically no diet performed better than another diet. But in one of them, they stratified people regardless of diet type from least adherent to most adherent. And wouldn't you know it, from least adherent to most adherent, there was a linear reduction in body weight. So again, I know this sounds very like, much like a cop out, but whatever you can stick to,

• 2:30Jen Cohen?

  Yeah.

• 2:30Speaker 02

  whatever you can sustain is going to be the best diet for you. Now, that appears to be extremely individual. I've had people say to me, I did intermittent fasting and I didn't even feel like I was dieting. I've had people say, I did, I tried everything and I did low carb and it felt easy. I've had people say, I did a plant-based diet and I was so full all the time, it felt easy. If you're gonna lose weight and keep it off, you have to follow some form of restriction. But you should choose the form of restriction that feels the least restrictive to you. And also don't assume it'll be the same for everybody. So for me, I tried the whole eat clean 20 years ago when I was getting into bodybuilding. What I felt, what I found out was I was binging on the weekends.

• 3:14Speaker 02

  And I remember one day I just had like mowed down a whole pizza and I was like, you know, I feel like it's not the pizza itself that's, you know, screwing me up. It's the fact I'm eating the whole thing.

• 3:23Jen Cohen?

  Yeah.

• 3:24Speaker 02

  So I'm gonna try and hit these calories and protein and carbs and fats. And let myself, if I feel like I want something, let myself have it. And wouldn't you know it, I had no problems after that.

• 3:36Jen Cohen?

  You didn't, you were able to stop at just a little amount?

• 3:39Speaker 02

  Yep. Now, that's, that's my personality, my psychology, right? So I'm somebody like, if I know I can have it, it makes me actually want it less.

• 3:47Jen Cohen?

  Yeah.

• 3:47Speaker 02

  Right? So I track my calories, I track my protein, I track my carbs, my fats. Now, for some people, that feels very overwhelming. It feels extremely restrictive. They just say, well, I'd rather just like reduce my carbohydrate intake and not worry about it. Okay.

• 4:01Jen Cohen?

  Yeah.

• 4:01Speaker 02

  Do that.

• 4:02Jen Cohen?

  Depends on who you are.

• 4:03Speaker 02

  But again, if you're, but funny enough, when I got into coaching people, I thought, well, I've got the solution. I'll just have everybody do this flexible dieting thing and this will solve all the problems. And of course, you know, learned, hey, dumb dumb, not everyone's like you.

• 4:17Jen Cohen?

  Right. What did you find for the people that you've trained? Of all the people you've trained, what has been, what has worked the most in terms of what you've seen?

• 4:25Speaker 02

  Well, flexible dieting has worked the most, but that's a selection bias because people come to me because they know I'm a flexible dieting guy.

• 4:32Jen Cohen?

  Right.

• 4:32Speaker 02

  And so then they end up wanting to gravitate towards that. And I'll always tell people in low carb or fasting, like they're like, look at all these people who've gotten all these results. I'm like, yeah, because they're coming to you.

• 4:42Jen Cohen?

  Right. They're your people.

• 4:43Speaker 02

  They're already sold on that, right?

• 4:44Jen Cohen?

  Exactly.

• 4:45Speaker 02

  So what I would say is like, listen, you know, I think that this is great news personally because it means the world is your oyster. Whatever dietary strategy helps you like be able to be consistent, just do that. I mean, we have like a nutritional coaching app that we designed.

• 5:04Jen Cohen?

  Right.

• 5:04Speaker 02

  Uh, algorithm based coaching app.

• 5:07Jen Cohen?

  What's it called?

• 5:07Speaker 02

  It's called Carbon Diet Coach.

• 5:08Jen Cohen?

  Right.

• 5:09Speaker 02

  So it's like basically like one-on-one nutrition coaching, but for a fraction of the price. So $10 a month.

• 5:16Jen Cohen?

  That's great.

• 5:17Speaker 02

  And it's all algorithm based, algorithm I helped write. And, um, but we don't, when it comes to dietary preference, we give people options. Do you want to be plant-based? Do you want to be low carb, ketogenic? Do you want to be balanced? Do you want to be low fat? And you can pick. And then even within those, we let you shimmy the numbers a little bit. So you can really get to something and we don't say, hey, you've got to eat five meals a day or three meals a day or eight meals a day. You get to pick based on what you feel is most sustainable for you in terms of dietary strategy.

• 5:47Jen Cohen?

  Oh, that's great.

• 5:47Speaker 02

  So, you know, I, I really think that reframing this stuff is like, we get into these diet wars. Everybody wants to be the winner and have their diet be best. And I'm like, shouldn't the goal be to like, just figure out what works for people? Like,

• 5:59Jen Cohen?

  Right.

• 6:00Speaker 02

  And people say, you can't lose fat eating carbohydrates. I'm like, how many millions of examples of people eating low fat, higher carb diets and losing? Fat and getting very lean, do we need before we say, well, that's obviously not true.

• 6:14Jen Cohen?

  A hundred percent true.

• 6:16Speaker 02

  I think people get so, and I'm guilty of this, it's like they find whatever worked for them. And then try to justify why it's the best thing to do. It's almost like we're just like, it's like teams, right?

• 6:27Jen Cohen?

  Totally true.

• 6:28Speaker 02

  It goes to politics, the whole, the whole thing.

• 6:30Jen Cohen?

  It goes with everything, but it's also like, cause we wanna, we don't, to change our minds is very difficult.

• 6:35Speaker 02

  Oh, yeah.

• 6:36Jen Cohen?

  Right? And so if we have that in our brain, it takes a, is it cognitive dissonance?

• 6:40Speaker 02

  Yes, cognitive dissonance.

• 6:41Jen Cohen?

  Yes.

• 6:42Speaker 02

  Great example of that, and this is an example of politics, but I think there was a study done like 10 years ago. And they showed both Democrats and Republicans facts that would either support or refute, like directly refute a position they held, right?

• 6:57Jen Cohen?

  Yeah.

• 6:58Speaker 02

  What they found is that whether it refuted or supported their position, both things were equally as effective as causing the person to become more entrenched in their beliefs. So when they presented facts.

• 7:12Jen Cohen?

  Yeah.

• 7:12Speaker 02

  To these people, and it didn't matter if it was Democrats or Republicans, both, this is a people problem. This is not a party problem. When they presented facts to Democrats and Republicans that refuted a position they held, people did not take the other side. They did not admit they were wrong. It actually caused them to double down.

• 7:28Jen Cohen?

  Yeah.

• 7:29Speaker 02

  And that's what's called cognitive dissonance.

• 7:31Jen Cohen?

  That's so true. I totally agree with that.

• 7:41Jen Cohen?

  I'm all about finding sustainable ways to optimize performance. The kind of work that actually moves the needle on how you feel and function. And that's why I really need to tell you about ProLon's five day program. Most of us are chasing quick fixes that never get to the root of the problem. And the result is sluggish energy, brain fog, and bodies running below its full capacity. But ProLon changes that by triggering your body's natural repair and renewal process at the cellular level. It's not a cleanse or crash diet. ProLon is the only patented fasting mimicking diet.

• 8:20Jen Cohen?

  At USC's Longevity Institute. It's a plant-based program with soups and snacks and drinks that nourish your body while keeping you in a fasting state. The benefits are backed by science, deep cellular rejuvenation, fat-focused weight loss, no injections, and better metabolic health and energy. Plus, improved skin and even reduced biological age. And here's my favorite part. It's a complete reset in just five days. No willpower, battles, no extreme restrictions, just a structured plan to let your body do what it's designed to do. Repair, renew, and optimize. And right now, ProLon is offering 30% off sitewide,

• 9:03Jen Cohen?

  plus a $40 bonus gift when you subscribe to their five-day program. Go to prolonlife.com/jennifercohen and use Jennifer Cohen to claim your discount and bonus. That's prolonlife.com/jennifercohen and use code Jennifer Cohen.

• 9:29Jen Cohen?

  Okay, I didn't ask you about artificial sweeteners, like stevia versus aspirin. Because I think you did something on Diet Coke. Like everyone, because if you were, if you hold a Diet Coke around these days, it's, you might as well just hold like a machete and like, you know what I mean? Like, it's unbelievable. Like, God forbid you have a Diet Coke. I'm like, that's my biggest weakness, you know, but ever. You don't think it's as bad as people think it is. Like, it's like, right?

• 9:55Speaker 02

  I mean, I'll tell people, do you want to discuss feelings? Or do you want to discuss what the data actually says?

• 10:00Jen Cohen?

  I want the data.

• 10:01Speaker 02

  So if we look at the effects on like type 2 diabetes, on weight loss. So if you look at correlation data, which is basically what characteristics do people who drink more diet sodas have? Well, you can find a correlation between obesity and diet soda. And so they've gone, aha, see, it's causing people to be fat. Well, that's like saying basketball is causing people to be tall.

• 10:27Jen Cohen?

  Right, yeah.

• 10:28Speaker 02

  Right? Like, but if we actually Look at the randomized control trials where they substitute diet sodas instead of regular soda. They see significant loss of body weight. And actually, people say, well, it's not better than water. There was a recent network meta-analysis done where they compared diet soda versus regular soda, water versus regular soda, and water versus diet soda. The people drinking diet soda lost a little bit more weight than the people drinking water.

• 10:57Jen Cohen?

  Stop it.

• 10:58Speaker 02

  Now, that's, diet soda is not a fat burner, okay? They're just eating less. So what that suggests is people are, if they're substituting with water, they're still seeking out that sweet taste somewhere else. So now people will say, well, that's just weight loss. Like, it can't be healthy for your gut microbiome and whatnot. So there's only a couple of studies in humans on the gut microbiome. Most of it's been in Petri dishes and high-dose rodent studies. It does appear that some of these artificial sweeteners do change the gut microflora. However, what we don't know is, is it a bad change, good change, or neutral?

• 11:36Jen Cohen?

  We don't know those things?

• 11:37Speaker 02

  We don't know those things, no. And I, I've talked to several, one of my colleagues who did her master's at Illinois, when I was doing my PhD in my lab, Suzanne Defcota, is one of the world's leading researchers on the gut microbiome. And I asked her about diet soda, and she said, uh, when it comes to gut health, it's one of the last things I'm worried about.

• 11:55Jen Cohen?

  Really?

• 11:56Speaker 02

  Yeah. So, for example, so there was a study done where they showed that, you know, uh, artificial sweeteners, I, I don't know if it was aspartame, I think it was sucralose.

• 12:06Jen Cohen?

  Which is Splenda? Yeah.

• 12:07Speaker 02

  Yeah, Splenda. They showed that, and, and it does appear to be artificial sweetener dependent. I, I don't know if aspartame changes the gut microbiome. Uh, there was a study looking at it, and I can't remember exactly which one it was. I know sucralose did. But if you look at the microflora that it changed in terms of reducing and increasing, they did note an increase in the production of things like butyrate and propionate. So if you go and look at the literature on butyrate and propionate, guess what? They actually appear to have health benefits. So now I'm not saying that artificial sweeteners are necessarily good for your gut. Saying is we don't know. But what I'll tell you is this. If I can get somebody to stop drinking regular soda and drink diet soda.

• 12:49Speaker 02

  And they lose 50 pounds and every time I post about this, there'll be multiple people say, all I did was cut out regular soda. And drank diet soda and I lost 50 pounds, 70 pounds, 100 pounds. You're gonna have a hard time convincing me regardless of whatever is happening with the gut microbiome, which we don't know. That that person is not healthier now for having lost 50 pounds.

• 13:08Jen Cohen?

  That is amazing. So what, where did this all come from?

• 13:11Speaker 02

  Uh, it's the natural, it's the naturalistic fallacy, which is if something is artificial, it must be bad for us. But if you look at like what aspartame breaks down into. It's aspartic acid, phenylalanine, and then it breaks down into methanol. Oh, oh gosh, methanol. Let me get to that. Aspartic acid and phenylalanine are amino acids. You get 20 times aspartic, the aspartic acid and phenylalanine in a steak that you do in a diet soda. All right. So let's just, let's just take those out of it.

• 13:37Jen Cohen?

  Okay.

• 13:38Speaker 02

  The methanol, you, it's such a small amount. Your body can easily metabolize it. And I believe you get more methanol in like a glass of tomato juice than you do in diet soda.

• 13:49Jen Cohen?

  Really?

• 13:50Speaker 02

  So because you have to understand while a Coke is like 40 grams of sugar. Artificial sweeteners are hundreds of times sweeter than regular sugar. So aspartame, I think is 200 times sweeter than sugar and sucralose is like 600 times sweeter. So you're talking about milligrams of this stuff. It's a very, very small amount, which is why, again, when they cite these rodent studies. Where they're giving a thousand times the dose of what they would normally give humans.

• 14:18Jen Cohen?

  Right.

• 14:19Speaker 02

  I kind of go, who cares?

• 14:21Jen Cohen?

  Doesn't matter.

• 14:22Speaker 02

  Now, I'm not saying people should drink diet soda. I'm not encouraging it as a weight loss tool. What I'm saying is right now, if you, if somebody wants me to say that it's bad for you. I don't think you can objectively say that. Do I think it warrants further investigation? Of course. But again, if it's a tool that helps people lose significant body weight and keep it off. Then I think it's a net win.