Caryn Zinn transcript

Written by Christopher Kelly

Sept. 8, 2014


Chris: Hello and welcome to the Nourish Balance Thrive podcast. I'm delighted today to be joined by Caryn Zinn. Caryn is a senior lecturer and nutrition researcher at Auckland University of Technology's Human Potential Centre. She's a New Zealand Registered Dietician and has a private practice where she consults with clients with varying needs, ranging from general health to chronic disease and athletic performance.

Hi, Caryn.

Caryn: Hi, Chris. How are you today?

Chris: Great, thank you. Thanks for coming on.

Caryn: Good. Not a problem.

Chris: I wanted to have you on today to talk about the trial that you presented at AHS which I thought was incredibly interesting. And so you put five multisport athletes on a ten-week ketogenic diet intervention. Can you tell me a little bit more about that?

Caryn: Yes. So I guess the study really originated from me talking about low-carb high-fat nutrition and ketogenic diets with my outdoor buddies, really. So these multisporters were all connections of mine involved in various sports. One was a 24-hour racing lady. We had people training for Kepler which is an ultramarathon in the south island of New Zealand. We had some endurance cyclists.

So they were really intrigued about the ketogenic diet and they really wanted to know whether they would get any kind of performance benefit and really any benefit at all. So they basically said to me, "We want you to use us guinea pigs, really." So that's how it came about. We scraped a bit of funding together as we do at universities and --

Chris: How did you do that by the way? That's kind of interesting to me in itself. How did you manage to get the money together?

Caryn: Well, interestingly our faculty every now and again -- well, I guess every year they've got this contestable fund and you put in for it with your study. So we actually put in for it thinking, "Oh well, if we don't get it we'll just try and do something else." We managed to get a bit funding to cover all the testing and to cover the ketone strips, and we already had a ketone meter, so it was real budget study but that was all we needed.

It wasn't a controlled trial or anything like that. It was just more of a case study, so it worked with very little money, but it was all profile the university, so that was great.

Chris: Excellent. So these were all endurance athletes, runners and cyclists?

Caryn: Yeah, runners, cyclists, kayakers and cyclists both road and mountain bike. So we had real mix of exercise types there yeah, but all endurance.

Chris: What was the goal? What were you setting out to prove?

Caryn: Well, they wanted to know if they could see any kind of performance difference, and one or two them in particular were interested in changes in body composition, but for the most part it was, "Let's just see what happens, really." One of the participants is working in the area of health and nutrition and just out of interest she said, "Let's do this and let's see what happens to our performance and our body composition." So I was really intrigued on those two variables: performance and body composition.

Chris: How did you design their diet? I know that a ketogenic diet doesn't really define anything exactly and that you would need to decide what people are going to actually eat. So who did that and how did you do it and what did they eat?

Caryn: Well, our crew just talked to them and gave them thresholds. We gave them example breakfast, example lunches, example dinners and example snacks. With the ketogenic diet, it's kind of interesting because when you read the literature it says that you have to have a carbohydrate level that's less than 50 grams of carbohydrate. And while that's all well and good, the reality is that you need around 20 to 30 grams of carbohydrate initially to get into ketosis which is very, very little and can be quite restrictive.

So we gave them that limit. We also gave them a limit of 1.5 grams of protein per kilogram of their body weight. There's varying amount of protein recommendations in the literature, so I guess we muddled through that and picked 1.5 as the ceiling, really, and then effect of satiety. Once we got some of their diet records through, we looked at where they fit and lay in terms of percentage of total calories. But I guess for us, the key was, is that they measured their own ketones so we knew instantly whether their diet was working or not.

So within those threshold constraints and examples of breakfast, lunch, dinner and snacks, they just started out and sent me their food diaries, and I just look over them, and between that and the ketone outcomes it was very clear who was taking charge and who wasn't.


Chris: What level of ketosis that they achieve in millimoles of their measurement of blood?

Caryn: Well, actually our male achieved a level around 4 at one point which is the highest that I've actually seen in athletes. A couple of our athletes really struggle to get into ketosis and those were the two that happen to be including a little bit of alcohol. So because we were at the start of our LCHF ketogenic research dubbing career we didn't know a lot about alcohol and there's not a lot of literate about alcohol getting into ketosis. It appears that if you do consume some alcohol you struggle to get in, but once you're in you can have a little bit of alcohol and stay in.

Chris: Oh, how interesting.

Caryn: Yeah, because it felt our way, really.

Chris: Okay, yeah. I didn't know that. I'd actually struggled a bit myself to get into ketosis and I think it was more to do with the level of protein I was eating, but I didn't know that about alcohol, and I guess I wouldn't have because I just don't drink alcohol anymore. But did you --

Caryn: Yeah. I guess it's got something to do with the -- because alcohol is preferentially oxidized, it just takes preference in terms of fat oxidation potentially. I mean that's what I've just sort of derived.

Chris: Yeah, it makes sense. So what was the outcome? Did some sort of testing start once the people were officially in ketosis or did you include the adoption phase in your testing?

Caryn: No. We did a baseline, so we did some testing. We did this incremental step test and we did body composition testing before they started. And then we put them on their diets pretty much straight away and let them go for ten weeks and we didn't really touch them -- we had a lot of contact with them and we looked at their diets and adjust it accordingly but we did a repeat of that testing after ten weeks.

Chris: Okay. So what happens?

Caryn: So what happened was everyone lost some body weight and everyone lost some skinfolds and it ranged in terms of weight. One woman's weight loss was 1.4 kilos and that was in a 66-kilogram female, and the most was a loss of just over 9 kilos and that was in a 63-kilo female. It's a lot of weight to lose when you're 63. In terms of skinfolds it ranged from -- we did sum of 8 which is the ISAK accreditation standard. So it ranged between 20 and 38 millimeters of skinfold lost which is substantial.

Chris: It's also everybody as well. So I know there's only five people, where everybody lost a decent amount of weight then?

Caryn: Yeah, absolutely. The female who only lost 1.4 kilos of weight lost 23 millimeters of body fat, so just some interesting findings there. One of the interesting things is one of the females that we had who was just over 63 kilos, she's a good friend of mine and she'd always struggled to drop the last 3 or 4 kilos despite being incredibly disciplined about her diet which happen to be moderate to high-carb, very, very low fat.

When she went on those, the weight was dropped off her, just amazingly well, and then to a point where too much came off and we almost tether at the end of the study. We were a bit worried. We needed to feed her up. That many skinfolds went down to 37 millimeters which is -- you don't really want to go any lower than that for a female.

Chris: Right, yeah. It's a problem I found myself as well, the fat so satiating and sometimes not eat enough food. You can tell from the numbers you get from a power meatist per se, and if you upload or run I'm sure it can give you some kind of energy and expenditure estimate. It's really easy to come up short on the total amount of food that you're eating for a day when you're eating such a high-fat diet just because it's so satiating.

Caryn: Yeah, it is. But I think particularly with her and with some of the others, there was a little bit of that fat phobia that started out, and that's absolutely totally understandable because we've been brought up in this dogma that fat is evil, particularly saturated fat. So to suddenly say to someone you need to eat 70 or more of your diet coming from fat, the very thing that you've avoided your entire life, that doesn't -- you just don't click your fingers and go, "Okay." So I think there was a little bit of that -- we had to really coerce her into having more fat and she did that but she still kept on dropping weight.


Chris: Yeah, we see that as well. My wife is a food scientist and she's been looking over the shoulders of people remotely using food diaries, and you sometimes see people who are really active or athletes. So if you see something like a third of an avocado or something like that, or a teaspoon of coconut oil, we're like, "No, you don't get it. It's more than that."

Caryn: I know. I used to be one of those dieticians that said -- dare I say this on air -- use like a rice bran oil spray for your cooking, so you'd get like a quarter of a teaspoon for your cooking. That was my practice before I totally changed my mind on the said thing. Now, the rice bran oil spray is only used to clean the barbeque.

Chris: Yeah, it's funny you see some of these seed oil, like flaxseed oil is a good example of it that some people use. In the UK they use it for oiling cricket bats. It's like that's all it's good for.

Caryn: What a waste of omega-3s though.

Chris: Yeah, good luck converting them. So what were the downsides? Why is everyone not doing this? Why is this not like a common best of practice? Why is this going on?

Caryn: Well, the other part of the study that I haven't really mentioned was the performance outcomes. When you look at some of the literature, some of the studies have shown no performance drop whatsoever and other studies have found a performance drop. We did find a performance drop in all of the athletes.

So they all mentioned subjectively that they found that they couldn't really find their top-end, and for a couple of them that was really important especially the cyclists, they needed to get that sprint capacity going in a race. But the two that were training for Kepler, they were just slow and steady the whole way. So it didn't really mattered to them but the performance here showed that there was a reduction in peak power and reduction of VO2max.

So that's the downside but I also think a downside to living in a ketogenic state is that it's pretty restrictive. I think LCHF or low-carb high-fat is dead easy because there's a spectrum, and if you can keep your carbohydrates under 100 grams a day, that's pretty easy to do but to keep it under 50 and even under 30 is hard.

Chris: It's almost impossible. If you're going to eat out, it's almost impossible I'd say unless -- I don't know.

Caryn: Yeah. I wouldn't use the word impossible unless you maybe got an Italian restaurant although you could always get a bit of veil but then again, yeah, it's just --

Chris: That's just high protein.

Caryn: Yeah, it's just a lot harder but the people who are doing it are reaping such benefits from it. The other thing is the longer you tend to stay in ketosis, the greater the amount of carbohydrate you can actually put in there. So you can take it up to 50, and some people can actually take it up to 90 or 100 grams and still remain in ketosis which is really, really intriguing.

Chris: Yeah, unfortunately not being one of those people but after ten months maybe that will change, maybe it will continue to evolve but certainly that's not been the case for me.

How exactly did you measure performance there? I'm just kind of a bit interested. It was just VO2max?

Caryn: VO2max and we did a peak power measure as well on an incremental step test.

Chris: Okay. So how long was the insofar then or the period at which they were producing power? Was it like 20 seconds or was it -- I'm just wondering how aerobic the activity was, right? So I'd expect the performance to increase, the longer the period and the more oxygen was being consumed for that period. So I'd understand if like the 20-second power test were to go down, but maybe not so much like a 10 or 20-minute.

Caryn: Well, it wasn't really a power test per se. It was more like a 45-minute test in total. They got them on a bike and they'd get them to start at however many watts for five minutes or something. And then they incrementally stepped up the intensity and that basically ended when they were out of juice. At that point, they looked at the power, anaerobic threshold, things like that.

Chris: So I think you probably need to do some more experimentation then, or each individual were to see how this performance or potential performance decrease applies to them as an individual in their specific sport I would say.


Caryn: Yeah, individual responses are crucial. What they've actually done since is they've all taken away something from the study and our cyclists in particular who found that she definitely lost top-end, she has now introduced quite a bit more carbohydrate into her day, around her training session and particularly in the recovery session, and she's found that she's got her top-end back. It's almost like the perfect outcome. She's got her body composition goals and by putting in a bit of carbohydrate, she's found her top-end.

So she would be the goal and that's what I try and give my athletes too at the end of their kind of fat adaptation period, is I try and put some carbohydrate back, certainly not anywhere near over 100 grams diet, but we try and kind of package the carbohydrate around and then after their training so they can get the balance of both performance and body comp which, of course, indirectly affects performance.

Chris: And she remained in ketosis whilst achieving that?

Caryn: This was after the study, so I haven't measured her ketone whilst she's put that carbohydrate in, so we don't really know about that.

Chris: So anecdotally I've experimented a little bit with this myself and so I suspected that maybe I'd lost a bit of top-end and some of it is difficult. You can lose quite a lot of power if you've also lost the body weight in cycling. So for me 300 watts became 5 watts per kilo which is really respectable with the level that I race. So I thought maybe 300 watts is okay now, where last year when I was eating more carbohydrates, I've seen more like 330, 340, 350 even.

As time went by I'm starting to suspect that maybe that's not just a body weight change thing and that I am seeing less power, less watts per kilo. I've experimented a little bit actually today with adding. So I got to the point, and I'm sure your athlete said as well, that you find that you just don't need to eat anything before, after or during exercises. It's something just a little bit difficult to get your head around at first that you don't need to be eating during your workout.

So I've gotten so used to that but I've tried adding a little bit of the UCAN SuperStarch which you may have heard of. And just today, like I had measured power on the same section of trail and saw quite a significant improvement in power for less heart rate after I'd added back the SuperStarch, but it's so difficult because there's no control. It's really almost impossible to tell what changed, so I'm really looking at that.

Caryn: Yeah, that's exactly right but you also need to question -- well, there's nothing dangerous about living in ketosis. You also got to question why you want to be in it if you're not getting the performance benefits by staying in it.

I think by initially getting into it and allowing your body to fat-adapt is great and then bringing some good quality carbohydrate around training, after various types of training sessions, that might be how you want to live long-term, and got in and out of ketosis maybe indicating your body is pretty metabolically flexible and utilizing the carbohydrate when it needs to most and utilizing the fat when it needs the most, and making sure that you don't get that long-term oxidative damage that you would on a very high carbohydrate diet. I also think that your body can still be fat-adapted when you're not in ketosis. Did I say that correctly?

Chris: Yeah.

Caryn: So you can still be fat-adapted and you don't have to be in ketosis to be fat-adapted.

Chris: Yeah, that was certainly true for me that I noticed most of the gains, the performance or when I say performance, just in how I felt throughout the course of the day mostly. I guess that came from eating more fat and going onto a high-fat low-carb rather than before ketosis. But for me the goal was blood sugar regulation. I found that I felt best in, say, the 80s and 90 milligrams per deciliter range around or 5-millimole or less with like glucose.

The only way that I could really get there was through like before ketogenic diet. I think that might be something to do with the way that I've eaten in the past and how much metabolic damage I have.

Caryn: That's right, yeah.

Chris: What were the people that you worked with like? Did they have any problems going into this in terms of their insulin sensitivity or were they all completely healthy?


Caryn: They were all completely healthy. Well, they were supposedly healthy but interestingly enough, one of the biggest, and I think the best outcomes from the study was really the unexpected outcomes. These people had massive improvements in certain areas. For example, two of the people, they had skin issues and their skin totally cleared up. One of them found that recovery, like she was doing this massively long runs training for Kepler, and the next day she'd go mountain biking with her mate. Her recovery was just amazing.

Another one who had an inflammatory ankle or ankle problem for years leading up found that the pain just disappeared. The most profound outcome really was from our male who -- it was quite funny. We stumbled upon this just by chance. I was chatting with him asking him how it's all going and he said, "Look Caryn, I don't know if you necessarily want to know this, but I've always had an enlarged prostate. I've had lots of issues and lots of meds. I changed my meds. I've tried everything. I've tried acupuncture." All those kind of stuff, and ever since going on the ketogenic diet, his prostate issue just cleared up and disappeared.

From an insulin resistance point of view they were probably fine, but all these other things just came out of the woodwork and I just thought that's outstanding.

Chris: Yeah, I've seen lots of mysterious stuff like that. Sometimes the symptoms you're not even aware of them. The inflammation and oxidative stress and recovery part really fascinates me because I definitely noticed it in my own training. Like today, for example, I did nearly three hours with six 10-minute threshold intervals. When I was still eating carbohydrates or drinking like a glucose solution, I guess you would call it, that kind of workout would just knock me sideways.

I will probably have to spend most of the rest of the day on the couch and I probably will just spend most of the day eating too. There's no way I could have really done much work and then least of all concentrate on a podcast afterwards. It's something I've really noticed, kind of less inflammation. So you saw that too. Do you understand any of the mechanisms? Do you have any insights and what might be going on there?

Caryn: Well, I think it's got something to do with -- it's definitely got something to do with sugar and carbohydrate, but I also think one of the powerful contributors is that ratio of fatty acids, omega-6 to omega-3.

Typically how we eat and how these people were eating was how they were always instructed to eat which is having industrial seed oils, using canola oil and rice bran oil and all those vegetable oils for cooking, and changing those oils to an olive oil for cooking which is high in monounsaturated, and also using more saturated fat from coconut oil and butter. But the other thing, the omega-3 content via other sources, it just created a bit of balance in 6 to 3 and that's definitely got some impact on reducing inflammation.

So whether it's the sugar, whether it's the fats or whether it's the reduction of oxidative damage and free radical clearance, I don't know the exact mechanisms, all I know is that it works.

Chris: Yeah, it could be more than one thing. I know that ketone bodies yield the same amount of energy for less oxygen so that possibly could be a flaw. Actually, you're talking about omega-3 to 6 ratios, it reminds me of another thing that I noticed was an elevated heart rate for the same power output and it didn't seem to matter and I don't really know why. So I just saw higher heart rates than I'd ever seen before. I'd go into a race and normally the way the heart rate works is it actually goes down, your maximum heart rate goes down as you age.

This year I saw some numbers that were 2, 3, 4, 5 beats higher than I'd ever seen before in the past. I emailed Steve Phinney about it and he talked about the omega-3 to 6 ratio that changes on a ketogenic diet and its influence on the central nervous system. But I wonder, did any of your guys see any of that, the elevated heart rate thing or is that something unique to me?

Caryn: We looked heart rate before and after in our test and there wasn't any major trend. Some of them went up, some of them went down, so there was nothing that we could see from there to get out of it, no. But interestingly, the whole inflammation -- just getting back to the inflammation aspect, I've got a lot of clients who are overweight, insulin-resistant type clients who are finding that they are having reduced inflammatory conditions or improved joint pain and things just by going low-carb high-fat and not going into ketosis.


So I think even a moderate reduction in carbohydrate, still that balancing of 6:3 definitely helps irrespective of whether you've got a high level of ketones circularly in your blood.

Chris: So were there any other unwanted effects, I should say, other than the performance decrease? You didn't have any of your women stop having their period or anything weird like that?

Caryn: We did have one that lost her period, and to be honest, I think that was because she was just getting too light and there was a lack of total energy availability anyway. I've worked with athletes that have high-carb low-fat diet and low-carb high-fat diet and you still see loss of period the other way as well. So I don't think it was anything attributed to the diet itself. I just think the extent of weight loss, body fat loss and energy availability was the result of that, yeah.

Chris: It's a dangerous and powerful tool in a way, isn't it? The way that you can use this to lose weight, but yeah, you need to be. I mean this is a really overt sign for women but I'm sure it's true of any athlete, of any age or gender, that if you're not eating enough calories it's going to be impossible to convince your body that now is a good time to be anabolic and be investing in long-term building projects and getting stronger and faster. It's just not going to happen.

Caryn: Yeah, exactly. So it can happen under any kind of dietary regime. The issue with this one, and this is a good, is that it seems so easy to do. I mean this was the female who struggled to lose the last few case and now she just --bang! 9 case gone.

Chris: Yeah, it's amazing.

Caryn: So it's that satiety factor and that kind of feeling of calmness where you don't need to -- you're not scrambling for another meal every hour or two, and not loading your body with so much carbohydrate during your training and during your regime. It's just very, very interesting.

Chris: It is, yeah. So in your practice now, say, I were to walk into your office and see you for the first time as I was several years ago. I got to the point where I was a complete mess. It's almost like crack cocaine to me, the gels, the maltodextrins, sports gels. I got into mixing those into the bottles I was drinking from and I was taking the gels every 40 minutes. I had severe hypoglycemic symptoms on the bike, off the bike if I didn't keep consuming carbohydrates. I was in a pretty bad state.

So if I was to walk into your office right now, how would you get me started onto a high-fat or even ketogenic approach? Would you take steps or would you just like drive straight in?

Caryn: It's a bit of a negotiation process for the athlete I think. I think the most important thing is to do it when the timing is right. So I always question my athletes very carefully about when have they got their important races, and if there's something coming up in two or three months, I don't touch them. Obviously, if you've got major issues with gels and things, we improve quality and I might drop some carbohydrate and add some fat in a more of a moderate approach.

I've got a couple of athletes at the moment. They're just coming back off injury and they then saw only next year, so I've said, "Right. Well, here's what I think might work for you. What do you think?" I always get their buy in. I don't push things on people. But these days people are coming to me because they know this is the kind of work that I'm doing. And then once they buy in, I give them the option of going low-carb high-fat gradually and then getting into ketosis, or I say, "Look, you can just bite the bullet and get in." And 99 out of 100 times people say, "Yup, bite bullet. Let's get in."

Chris: That's what's great about athletes is they follow all the rules and they get really excited about marginal gains and they measure everything. I think they're great people to work with.


Caryn: They are definitely, like "If we're going to do this, let's do it." So we just get them going into it straight away, and I've got a ketone meter in my office and I measure their ketones when I see them. I take their body fat when I see them. I liaise with their coaches or trainers. I look at what's happening to their training program and once they're fat-adapted, if they start ramping up their program, we might start building in a little bit of carbohydrate based on how their feeling.

So it's quite different from the randomized controlled trial. Once you're fat-adapted, that's cool. Once you've got your body composition goal, that's cool. Let's now work out what makes you feel -- so that you're performing at your best, and it might be that they stay in ketosis for some, but for others it might be that they need just a high level of carbohydrate and it's just so individual.

Chris: So that's how you work then, you deal with the nutrition side and then typically somebody else has the trainer that's defining like a plan for them?

Caryn: Oh, definitely. I wouldn't touch that. I'm a dietician and I'm very much a part of the team, not the whole team. So I like to work with people who are experts in the field and I don't -- in the old days for weight loss you would rely so much on the energy expenditure side of the equation and you'd want to say, "Well, can you just put in a few extra runs or walks?" which would interfere with the program that the trainer has painstakingly set for the athlete. In these days, I just don't touch it and I'll say, "Look, I'll ring you a coach and we can talk about it" and it just works beautifully that way.

Chris: The question I get all the time is, "What the heck do you eat during exercise?" What do you recommend?

Caryn: Again, it's a bit of a negotiation. So some people who are okay with gels and sports drink, we might still use a little bit of it and for others who have got more gut intolerances and gut issues probably like you, we look at other things. So some people use coconut creams and coconut oils and various blends of that kind of stuff. Nut butters are quite good and cashew nut butter is quite good because cashew nuts naturally hold a little bit more carbohydrate than almond butter.

Chris: You don't worry about the omega-3 to 6 ratio of the nut butters then?

Caryn: Not during racing or during training. I always tell my clients not to go nuts on nuts.

Chris: It's like crack cocaine to me. It's like another one of those things I just had to go cold turkey and just get it out of my life because I just ate too many of them.

Caryn: Yeah, and we do need to question people around that. I think that's held some really good nutritional value. So you've got to just work it in with your other omega-6s, and if the portions are able to be controlled or if it's restricted to using nut butters during race or something, then I'm not concerned about nuts because they've just got such a great nutrition profile.

Chris: Okay. Coconut cream is another interesting one. I'd not really thought of that. That's another one of the -- I have this long list of things that I've been addicted to in the past. I seem to have a very addictive personality that gets hooked on things quite easily, and I found the coconut cream, the concentrate. You can get it here. You can buy it on Amazon. I forget the name of the company that makes it but it's super cheap and this comes like this block. I think the idea is you're supposed to rehydrate it or something, but it's got a tiny bit of sugar in it and it turned out to be quite a hyperpalatable combination for me that I could just eat like a Mars bar almost.

But, yeah, that might be. If you could stay off it once you are off the bike or if I could stay off it, once off the bike that might be quite a good option as well, super high fat but then just a tiny bit of carbohydrate as well when you go a little bit harder.

Caryn: Yeah, and as I've said people are -- everyone is really individual. Some people like to put coconut cream in those little fuel bottle things in a fuel belt instead of filling it up with sports drink or gel, they just put some coconut cream and drink it and then some others use -- you can make those fat bongs.

You can put desiccated coconut in a blender and blend it so that it comes to a bit of paste or like a butter consistency, soft butter consistency, and then just pop them in the fridge for 20 minutes until they harden and then you can leave them in a container in the cupboard. You could add some carbohydrate source to that or you can just use that as a bit of fat source and then use a separate carbohydrate source like a bit of dry fruit if people can tolerate dried fruits which is an interesting thing. You either know you tolerate it or you don't. I think based on experience, you choose accordingly, really.


But I think that for people who are fat-adapted, they never need the amount of carbohydrates that they did before during racing. So the 1 gram of carbs per kg body weight, you don't need it. Some people still use it and do well on it but other people find that they can have a half of it or even a quarter of it. And then some of Steve Phinney's crew, they would say that they need nothing. And Tim Noakes' crew from South Africa, he would advocate pretty much minimal carbohydrates during racing and people do fine. And so there is that individual response again.

Chris: I just wonder what's going on there though for those people. With Tim Noakes' crowd, he's just doing events that's so long that maybe they can train and become so well fat-adapted that they don't often go into that more so of anaerobic pathway or maybe other types of athlete, like I'm sure for me on the mountain bike, and then I'm just coming into cyclocross season. It's autumn here now and it's almost like a series of short sprints cyclocross. On paper it looks like it's just a time trial, a 60-minute time trial.

Actually, when you look at that, with the power meter you'll see hundreds and hundreds of very short sprints as you leave all these different corners and it seems impossible to believe that you could be completely burning fatty acids during those little sprints as you come out of a corner. So I wonder what you think is going on there when you're not eating any glucose, and yet, you're using it? Do you think it has something to do with stress hormones and output from the liver? What do you think is going on?

Caryn: Possibly. I mean, the body is pretty advanced in creating its own level of glucose supply. So perhaps that's happening through gluconeogenesis. Yeah, that would be my best bet I think. I haven't really given it a huge amount of thought.

Chris: Sorry, I get too much into the geeky sport science thing which I know not your first and foremost area of expertise.

Caryn: No. I need to get into the geeky sports stuff. I'm too grounded in practice, really. I believe the athlete knows more about their body than anyone can tell them and they know when they are doing well or when they need a bit more of something and we work it out because this is an area that it's got so many unknowns we tend to muddle our way through it and the negotiation with me and the athlete. But I definitely think there's long endurance events where you don't really need to tap into any kind of decent intensity. You can get by just fine on fat.

Chris: Yeah, absolutely. So tell me, how do you use this in practice because it's not just athletes that you work with, right, it's people of all types?

Caryn: Yeah, definitely.

Chris: So when you get, say, a middle-aged man who is clearly quite insulin resistant and is using a high carbohydrate diet, would you just dive straight in and say to him, "Have you considered a ketogenic diet?" What would you do for him?

Caryn: No, I wouldn't dive into ketogenic diet. In fact, I very seldom dive into it. I use it more for people who are already on low-carb high-fat and just need that extra boost going. I think if you've got an overweight male or female and you look at their diet, and it's typically bad in my current worldview and probably not too bad in my old worldview, you just know that they are insulin resistant and when you drop carbs and add fat they'll lose weight and that happens every single time.

So to me someone who is insulin resistant, it's a complete no-brainer. Insulin resistance is a problem of carbohydrate intolerance essentially, so why would you treat it any differently to how you'd managed lactose intolerance or gluten intolerance. You just take away the problem first.

Chris: Isn't that interesting? I've never heard it described like that but it seems so uncontroversial when you put it that way whereas --

Caryn: Yeah. I keep thinking, "What am I missing here?" And my method was in a chapter in a textbook on something because every time I sit my client down, I think, "Why are there so many people that are into this way of eating?"

Chris: Yeah, I don't know. I think a lot of people, especially in the sports industry, I feel like a lot of people have cashed in on sugar and how addictive it is and if there were to be some mass change, imagine if everybody stopped using maltodextrin tomorrow. I mean that would be a huge change in sports nutrition. I don't know, maybe that's a part of it.


Caryn: Yeah, it would be better if the average Joe Bloggs decided tomorrow that everyone was going to stop eating like nutrient-poor cereals, I mean that would be awesome because then the food industry would have to shut down because they wouldn't make any money and then we'd get some progress.

Chris: Yeah. So tell me, what does the rest of the diet look like? Do you concentrate on nutrient density or is it a Paleo diet? What are you recommending for your clients or patients?

Caryn: I guess my philosophy is really all about whole food, all about real food. I think that Paleo is a really good concept. I don't subscribe to the name Paleo or anything like that but the concepts are great. I'm focused on nutrient-dense whole foods like eggs with vegetables for breakfast and big salads for lunch that have got some gutsy things in them. I think people are just limited by the lack of imagination when it comes to salads.

Chris: And then what about meal time? Do you think they're restricted by what they conceive to be different times of the day and what they should be eating at that time?

Caryn: Oh, definitely. If you asked everyone who stopped for lunch at twelve o'clock whether they were hungry, I think 20% of people -- well, the carbohydrate people would be hungry but…

Chris: I was always hungry at twelve o'clock especially when I see…

Caryn: Yeah, I think people are governed by time.

Chris: Do you know what they eat? People say to us all the time, "Oh, what am I going to eat for breakfast?" Some people that we work with, they need to do a full autoimmune protocol which has eggs excluded and they maybe are coming from a Paleo type diet and the first thing they say is, "Oh, what the heck am I going to eat for breakfast? I have eggs every morning." Do you encourage people to get away from those ideas as well? Have you got other ways to work around that?

Caryn: I just think people need to think about what foods they can tolerate and what foods they can't. If you can't tolerate a certain food, don't eat it whether it's egg, whether it's milk, whether it's peanuts, whatever. For whatever reason, if you have an intolerance, even if it doesn't come up in medical testing which it probably won't. If it doesn't sit well with you, don't eat it. Your body is trying to tell you something.

Chris: Yeah, absolutely. What do you think about vegetables and how much vegetables people should be eating even if they're on a ketogenic diet? I've seen some arguments that you don't need to eat vegetables, you can get all of the nutrients that you need from animal products alone or animal foods alone. Is that an approach you subscribe to or you're encouraging?

Caryn: I think that if people ate the livers, the kidneys, the brains and the organs of the whole animal, I wouldn't worry about vegetables so much, but people just don't eat like that. When you say liver, honestly, they'll just run out of your office in a hurry.

So I think on the basis of how we are currently eating animal foods which is the muscle part of it with a bit of fat, I don't actually think we do get all the nutrients so I think we need to look at vegetables and optimize the color and the variety of vegetables that we consume to get that variety of nutrient intake.

I think on the ketogenic diet, you're obviously a lot more limited and sometimes even your non-starchy vegetables you need to control to get around 20 to 30 grams, like the initial phase of getting into ketosis, and uplifting your carbohydrate to 50 or 60 you can pretty much, to a certain extent, go unlimited with non-starchy vegetables. But with starchy ones you always need to be a little bit careful.

Chris: Do you do any micronutrient testing in your practice? Do you actually look to see whether people are coming up short on any of the micronutrients?

Caryn: No, I don't do any kind of invasive testing but I put their diets through a dietary analysis program.

Chris: Okay. What do you use?

Caryn: We've got one called FoodWorks.

Chris: Is that something at the university?

Caryn: Well, university or practice. You can actually buy the designer software but it's got an Australian and New Zealand database of foods. The really amazing thing about that is that it's got a little partner app on the iPhone or iPad called Easy Diet Diary and people can download that free on the apps. They can fill in their foods and they can press send. It says, "Send diary to your dietitian" and I can pick it up in my end and see what they eat and do some analysis.


So it's a great little program, and I quote it up and I look at the RDIs and the AIs and things like that. You could also question whether RDIs are actually a true thing, you know what I mean?

Chris: I want to win the race. I don't want to, I guess, not die honestly, not go away.

Caryn: Yeah. Also, if somebody is low on a nutrient, are they really going to get a deficiency and how low? And maybe if they have a little bit of food every now and again, that's got that nutrient. I've just got all sorts of questions around Recommended Daily Intakes and deficiencies and things probably because my questioning mind after changing from the current state of nutrition, high-carb low-fat and moderate protein and the other way around, I'm not questioning everything.

Chris: Yeah, absolutely. I think that's really a good way to be --

Caryn: Yeah, I still look at the nutrient intake and for the ketogenic diet I actually recommend that people take a multivitamin as well just as an insurance type thing.

Chris: I think just because it's not perfect doesn't mean you should ignore it completely. I look at all of these things as kind of hints rather than any one of them being the silver bullet that's going to make or break the different because it's just not going to work like that.

Caryn: Yeah, that's right. I agree.

Chris: So the food diary app, it's not painful so I tried a new one. The one I'd used and quite liked in the past is called CRON-O-Meter. I spent a lot of time on that at one stage and I got to the point where I really liked it. You can do things like to find your own foods and copy meals and things like that and it got quite good.

And then I looked at another one, I won't mention the name of it, the other day and it had been recommended somewhere and it was hateful. The database was just full of the standard USDA packaged foods. You just had a serving of beef stew and it was made by my wife from scratch, everything from scratch with boiling broth and all the rest. And, of course, when you type in beef stew into the app, there is some brand name I don't even understand or recognize.

Clearly, this is not the same food that you are entering as to the one you've just eaten. And so the app that you're using does it have that problem or is it different?

Caryn: The app that I'm using is it's got an established database which is pretty comprehensive. Our food supply is probably a little bit smaller than in the UK and the US, so we're kind of lucky in that way. But it's also got a little space where you can enter your own foods and their own nutrients in it. It can get as accurate as you want it to get. I always tell people too, if they're having an omelet to itemize the ingredients and get as accurate as possible because if you select the default omelet, you don't know how many eggs, you don't know if they put any butter or what.

When they itemize their food then you're getting as close as you'll ever going to get. Well, I am really, really happy with it but it's only iPhone. The other smartphones can't use it. But also some of the other apps and I probably shouldn't mention a name as well. On a big central database, they allow you to enter your own foods so that the world can use it.

So if it's an American database, I can enter some New Zealand based foods on it and other people can then pick up those foods and use them. But the problem is, is that you're only as good as what you enter. I'm finding that some clients who don't have iPhones bring in their printers and then you look at a certain food and someone who has entered total calories but they haven't entered the carbs, protein and fat, and they certainly haven't entered the micronutrients. It just doesn't give you an accurate picture at all.

Chris: Yeah, I know. It's really tough. I feel like, with the way that we eat, we'd have to start from scratch with every single thing. You gave an omelet as an example there but literally every single thing that I eat, nothing is packaged or processed or even the same each time. So I don't know. Do you have some success then asking people to do this? It seems like such a lot work for someone to do but people are doing it.

Caryn: People are doing it. I always tell people that when they work with me it's almost like a two-phase process and the first process is where they up-skill themselves. They get to learn a lot about where you find nutrients in food. So I say to them, "It's pretty intensive. You need to track your food intake, email it through, we can talk about it."


Once they've done that for a certain period of time, and that's different for different people, it might be two weeks or two months, then phase two becomes a no-brainer because when you go to a restaurant and order something, you should be able to pretty much dissect what's in it and know how much carbs, protein and fat to a certain extent you're going to get.

So I encourage people to do it. Sometimes people come back and see me and they haven't done it, and if they've still lost weight and they're feeling good I'd say, "Look, it's fine. That's actually fine. We're still making progress." Some people find they like to go back to it every now and again just to keep them on track.

Chris: I see, yeah.

Caryn: Yeah. I mean, if you look at the weight loss literature or the weight loss maintenance literature, those people who track their weight regularly and track their food regularly are more likely to keep their weight off long term.

Chris: Yeah, I think that's true of any variable, isn't it? I can't remember who said that originally, "That which gets measured improves." Is that maybe even an Einstein quote, I don't even know.

Caryn: Oh, we'll just make it yours today.

Chris: It's true of anything though. If you track it, it's going to improve, no question. So what are your future plans? I wondered if you were going to do any more trials or any more experiments. What's going on?

Caryn: Oh, definitely. We've got some really exciting stuff in the pipeline. We've got a study called Low-Carb Kids starting shortly, really. So we're giving kids between the ages of 8 and 13, and it's really a whole family approach, and they are overweight kids and we're putting them on low-carb high-fat, not ketogenic diets at all and just keeping them under 100 grams of carbs and looking at weight loss over 12 weeks.

We're doing that, really, as a feasibility trial to see how they are finding the foods, how they're families are finding the foods, what the perceived cost or cost effectiveness of eating like this is, what the adherence is, what the attrition rate is. So that's going to be a really good study and if it works out well then hopefully we'll get some funding for a full randomized controlled trial in the area of children. We've been funded by our Health Research Council to do that and I couldn't believe they funded us because it's a pretty controversial area. So that was absolutely fabulous.

We've got a rowing study due to start as well. We were tossing up whether we were going to put them on ketogenic or just low-carb. We've gone with low-carb for various reasons but we're looking at immune factors as well as performance and body comp factors with this group, so that's exciting. And then we've got a whole host of PhD students looking at this kind of stuff as well. So we've got weightlifter study, we've got a military study going on. Basically, the Human Potential Centre in Auckland, we've just turned all our attention into low-carb high-fat nutrition, so it's very exciting.

Chris: Excellent. That sounds amazing. So where can I go to find out more about your research and then you as a practitioner?

Caryn: That's an interesting question. You can go to our Human Potential Centre webpage. We've got a little bit of stuff on there at the moment. My personal webpage is about to be launched over the next few weeks. It's been a work in progress in the last five years. I must be the dietician who doesn't have a website. So it just gets put on the back burner when other things come up. So that's coming. I do have a nutrition Facebook page.

Chris: I was going to say you're on Facebook, I know that.

Caryn: Yeah. So Facebook page Caryn Zinn Dietitian and I just post regular updates about, really, most things related to low-carb high-fat. I just got consultations as well. So I talk to people overseas and also face-to-face. So yeah, that's me really and I'm on Twitter of course.

Chris: Excellent! Well, I'll link all those things that do exist right now in the show notes for this episode. It would be interesting to see. Do you think any of these studies especially if they turn it to full clinical trials, will they be publically available? Will anyone be able to read those?

Caryn: Oh, definitely. Being in academia one of our goals is to publish our findings and disseminate to people. And I see these days that even case studies are going to published. So it's just getting the time, like a multisport study we want to publish and pretty much all of it. It would definitely be out there.

Chris: Excellent. Thank you very much. That's brilliant, really good. Well, thank you so much for your time today. It's been a really interesting conversation. I love what you're doing obviously because I'm doing it myself. I think it's really important work and I'm really grateful for it. And so, yeah, thank you for your time.

Caryn: Thank you very much for the invite and all the best with the tweaking of your nutrition for your performance and do keep in touch, let me know how it goes.

Chris: Okay, will do.

Caryn: Great! Thanks, Chris.

[0:55:16]End of Audio

Join the discussion on the NBT forum when you support us on Patreon.

Register for instant access to your FREE 15-page book, What We Eat

© 2019 nourishbalancethrive