Intermittent fasting and time restricted eating is a diet trend that continues to appeal to a huge number of people hoping to change their health and fitness.
But is this the magic bullet to all your health problems or is it a gimmick that is leading people astray?
As is often the case, the truth is somewhere in the middle.
Today, I wanted to talk about the pros and cons and simply weigh in on this topic which feels like it is just getting louder and louder
In this episode I share:
- How I’ve seen some people using fasting
- What IF and TR actually is and what it does
- The gut health benefits to fasting
- Why time restricted eating is not the answer to fixing your gut health
- Why these trends can be a band aid measure for some people
- Who can benefit from using this
- Who wouldn’t actually benefit from using fasting and why
- An example of how fasting helped an afl player short term but not long term
- What I require from clients before I consider fasting for them
- The work out routines that fasting won’t work with
Key Quotes
“I’m seeing a lot of people subscribing to intermittent fasting as a way to put a band aid on their poor lifestyle choices.”
“If you are someone training like an athlete, at a high intensity, maybe intermittent fasting isn’t the thing for you to be doing all of the time.”
If you don’t address your nutrition and what you are eating, please don’t kid yourself and think, I’m intermittent fasting so I’m all good here.”
Episode Resources
Jessica Spendlove Website – www.jessicaspendlove.com
Jessica Spendlove Keynotes – JessicaspendloveKeynotes – Jessica Spendlove
The High-Performance Profile Quiz https://jessicaspendlove.com/quiz/
Jess Spendlove Instagram https://www.instagram.com/jess_spendlove_dietitian/?hl=en
Jess Spendlove LinkedIn https://www.linkedin.com/in/jessica-spendlove-64173bb8/
About Your Host
Jessica Spendlove | Wellbeing Speaker & High Performance Strategist
Jess Spendlove is an international wellbeing and high performance speaker, coach, and advisor. With over 15 years of experience across corporate leadership, elite sport and the military she is known for helping ambitious leaders and teams optimise energy, build resilience, and sustain peak performance.
As one of Australia’s leading performance dietitians and a trusted voice in executive wellbeing, Jess delivers science-backed strategies that empower individuals, teams and organisations to thrive under pressure and achieve long-term success.
Episode Transcript
The following transcript has been automatically generated and not checked for accuracy
Jess (00:02.482)
Welcome to another episode of Stay At The Top. This week I am talking all things fasting and it’s maybe a little bit of a different conversation to what you might’ve listened to on other podcasts. Today I’m sprinkling in a little bit of the science but it’s more of a real world conversation about what fasting is, who should use it, who shouldn’t use it and how I see it being
and how I see it being used. Hint, it is an advanced tool that should be used by an advanced user who truly understands.
how to eat to optimize their energy, their performance, their health, their wellbeing, and their longevity. Today’s episode was inspired by conversations I’ve been having with elite athletes who’ve been using fasting and probably shouldn’t be. And it’s also been inspired by a lot of different clients I’ve seen using fasting as, to be honest, a band-aid excuse for their poor lifestyle choices. It’s a little bit of a spicy episode, I hope, but I hope…
It’s a little bit of a spicy episode, but I think you’ll find a lot of value in it because it’s a conversation I haven’t seen anyone having, and I wanted to go there. I also know that a lot of people listening to me are elite athletes or they train like an athlete, or they just really wanna have this, they’re an elite athlete, they train like an athlete, or they’re someone that might be using fasting as a tool when it may or may not be suitable. So…
They’re someone that might be using fasting as a tool. Scrap.
Jess (02:05.544)
As always, I hope you get a lot of value out of today’s episode.
Jess (00:07.394)
Today I want to dedicate an episode to talk about intermittent fasting, time restricted eating, some of the considerations and just…
Jess (00:20.926)
and just spend some time talking about ARIET and spend some time talking about who should use it, how they should use it, who shouldn’t use it and just come at this topic from a little bit of a different lens. Now the way I see a lot of people talking about it is this is the science, this is the benefits which don’t get me wrong, that is how I see it.
How I see intermittent fasting getting spoken about is that it’s just the greatest thing in the world. This is the research, it’s the answer to longevity, it’s great for our microbiome, it’s great for manipulating energy intake, there’s some cardio metabolic benefits which I agree on all of those points but what I want to talk about today is who it is not necessarily for.
and for the people using it, how they need to look at it. So the first point is, so this conversation has been inspired from a few different conversations or observations that I’ve either had or made.
One of them is an elite athlete that I’ve started working with the last few months. And this is someone who trains five days a week. That is their career. They are very active. And they started using intermittent fasting as a way to…
They started using intermittent fasting because they’ve heard the science and the benefits and they thought this could be something really good for my performance, for my longevity and can also be a really good way to manipulate weight. But diving deep on some of the goals and some of the parameters that he’s got, it became very clear that the fasting was actually inhibiting his performance. Similarly with other clients that I work with
Jess (02:23.412)
executive founders and they’ve got amazing performance goals. They might be looking to run marathons or do Ironmans or they’re just training like an athlete which means they train once or twice a day and similarly for these types of people intermittent fasting or fasting just may not may not actually be supportive of what they’re doing. Now I’m not saying blanket rule never fast but I’m just saying I want to have a conversation today for the types of
of clients that I work with, the types of people that I know are out there that exist on how they can use these tools, how they can use the tools, should they use the tools, and what are the things they need to consider. Now, the other side of the coin in terms of what inspired me to record this conversation is I’m also seeing a lot of people subscribing to intermittent fasting or undertaking time restricted eating.
as a way to justify or put a bandaid on their poor lifestyle choices. And I am here to call that out.
Intermittent fasting is not going to solve all of your problems if you don’t learn how to eat, how to leverage the power of nutrition and how to use nutrition as one of your main pillars for optimal health, vitality, well-being and longevity. Simply eating between a certain time frame will not override the ultra processed foods, the alcohol, the refined sugars, the high saturated fat and
nutrients, antioxidants, vitamins, minerals, all of the quality nutrition. So today is covering off both sides of… Today is coming at this… Today’s discussion is considering both of those… Both of those circumstances which I’ve become more… So today’s conversation is based on both sides of that conversation.
Jess (04:34.238)
Now I thought a really good place to start would be to define intermittent fasting. To define intermittent fasting and also time restricted eating. Now intermittent fasting first became popular with either the 5-2 diet, you know, eat normal five days and then have a really low energy intake for two days. Then next.
Then very close to that came the idea of the 16-8, which is we fast for 16 hours and we eat within eight hours. Similarly, a lot of the messaging around both of these styles of eating were really around eat normal, just keep eating what you’re eating, but either on those two days a week, really restrict your intake and eat 500 or 800 calories a day or whatever it might be. And similarly on the 16-8,
was really restrict your eating to an eight hour window and you’re all good. Now, I’m not debating whether or not there is benefit to fasting under the right circumstances, but what I have a bit of a bee in my bonnet on is the messaging around just eat whatever.
Jess (05:58.254)
is just eat whatever, which is just absolutely not the case. Fundamental nutrition principles and pillars, eating as many whole foods as possible, eating high fiber, nutrient rich, antioxidant rich, minimal processing is rule number one, is priority number one.
The quality of what you eat is fundamental to every aspect of your health and your wellbeing, both now and in the future. Now, I’m not debating that tackling.
Jess (06:39.262)
Now I’m not debating in some circumstances that intermittent fasting and time-restricted eating can be really beneficial. There’s been some really great research by Dr. John Hawley, who I respect and I admire so much, where over seven weeks, 131 overweight women were allocated to two different interventions. What were…
were divided into four different intervention groups. Now this research was particularly looking at the effects of time restricted eating and high intensity interval training.
Jess (07:19.774)
For seven weeks, the design of the study included, for seven weeks, one group did time-restricted eating, so they consumed all of their nutrients within a 10-hour window of their choosing, which is really important. It’s not about having to do it at a certain time. It’s matching it to their circadian rhythm.
Jess (07:40.83)
Another group did high intensity interval training three times a week for 35 minutes. The fourth group did both together, the time restricted eating, so they ate within that 10 hour window, and they did the three sessions a week.
And then the fourth group acted as a control group. So there was four different groups and they wanted to assess was time restricted eating, high intensity interval training or the combination of the two more effective. And they were looking at a number of metabolic parameters, things like visceral fat, blood glucose levels, overall weight and overall weight.
Jess (08:25.218)
The researchers took various measures of cardio metabolic health before and after the trial. And what they found was that the time restricted eating and the high intensity interval training group improved nighttime glucose levels, their longterm glycemic control, which is measured by your HbA1c, they reduced visceral fat and they increased their cardio respiratory fitness the most. So that’s really exciting to be able to, that’s a really important exciting piece of research.
to see that the combination of those two things together. We’re not saying workout every day. We’re not saying go on these elaborate water fast. We’re simply saying by limiting your intake of food for the 10 hours, high intensity interval training for 35 minutes, three times a week, you’re going to have profound improvements in those parameters for overweight women. Fantastic. The other really, the other…
The other area I’m really interested in when it comes to the time restricted, when it comes to time restricted eating.
Jess (09:38.242)
The other really exciting area when it comes to time restricted eating is the impact that this can have on the microbiome, on your gut health. So what we’re seeing is that time restricted eating has a great impact. Time restricted eating has a positive impact on gut microbiota composition, and it also showed that time restriction and meal sizes changed. Sorry, scrap that.
The other really interesting area when it comes to time restricted eating is the some of the benefits that are being seen in the gut health space. So there’s research coming out showing that time restricted eating, so if we’re eating over a 10 or a 12 hour window, this positively impacts our gut microbiota composition. So from that side of…
So from that side of the conversation, there is definitely some benefits to simply tightening up the hours that we eat. It doesn’t again have to be one meal a day or three day water fasts and all of this stuff which is out there. It’s simply saying if we eat between a certain window and we have space, we allow our digestive system the ability to rest.
that has a positive impact on our microbiome. And I think that’s a really important, helpful piece of information there. However, again, I really wanna highlight that if we are not fundamentally eating to optimize our health and our microbiome, if we’re not looking to increase our plant diversity, increase our fiber, eat more whole grains, more fruits, more vegetables, more lentils, more legumes, more nuts and seeds,
Jess (11:21.292)
protein and reduce our overall consumption of ultra processed foods, we really need to consider then are we doing everything that we can. And while yes there is some benefit to doing the time restricted eating which might be a first step, might be a nice entry point for people, I’m really here to drive home the point that, I’m sorry, you need
I’m sorry, if you don’t address your nutrition and what you are actually eating and putting in your mouth every single day, multiple times per day, please don’t kid yourself and think that, all good, I’m just intermittent fasting and I’m time restricted eating so I’m all good here. Yes, it might give you some benefits, but it is not the solution that you are after. It is potentially the band-aid.
Jess (12:16.548)
of things with the types of clients that I work with, I really see it as an advanced tool. And I’m sorry but most times you don’t earn the right to use that advanced tool until you learn how to fundamentally eat. And learning how to fundamentally eat means you know how to eat for optimal energy. So elevated energy levels and more consistent energy levels. Absolutely fundamental to you living
the best quality of life. Understanding how to eat to manage your appetite. I had a conversation yesterday with a client when you learn how to eat consistently with the types of foods and the combination of foods that you need you should never be getting to a meal or snack absolutely starving. We don’t want you to be full and forcing yourself but you shouldn’t be ravenous and just ready to devour anything in sight. What we want is that you’re getting to the meal, you
but you were not an 8, 9, 10 out of 10 starving. Because when you get to that point you overeat, you eat fast and then often you’re then, once you’ve had the meal you don’t feel satisfied and sooner or later you then have cravings. Sweets, chocolates, cakes, whatever it might be. So when you learn how to fundamentally eat, it addresses your appetite and your cravings as well. They are eradicated.
I’ve said it once and I’ll say it again, I don’t believe people are sweet tooths. When someone’s like, I’m just a sweet tooth, I need chocolate after dinner every night, I’m like, I know for fact, without even knowing what you’re eating, that you were not balancing your protein intake across the day, you’re probably not getting enough fiber, you’re probably dehydrated, and you’re probably not eating consistently. I have seen time and time and time again,
swear that they are sweet tooths. Athletes, CEOs, busy professionals, everyone, you name it. I do not believe there is such thing as a sweet tooth. It is simply you are not.
Jess (14:29.222)
meeting your nutritional requirements and you haven’t learned how to eat to manage that. Now I’m not saying to never eat those foods, those foods are delicious, but there is a difference between like desiring and oh my goodness I absolutely need to have this and this is all I can think about to oh wouldn’t it be nice just to have this and having it and being satisfied and stopping there. They are two very different things so you need to learn to
appetite, cravings, and there’s just performance in day-to-day life. Like if you’re an athlete or you’re active, you wanna be training hard, you wanna be improving, you wanna be recovering, when we’re thinking about cognitively each day.
We wanna feel focused, we wanna have good productivity, we want to mentally feel refreshed and not fatigued. These are all signs and factors that nutrition influences. So when you’ve learned how to eat, to manage and optimize them, then I see fasting having a place for certain people. But what I really wanna call out here is…
who I don’t think fasting is appropriate for. I don’t think that conversation is had. It’s had from the lens of, look, if there’s medical issues or you’ve got…
Sorry, it is, this conversation happens from a lens of if you’ve got a medical background, if you’re on medication, you know, seek professional advice to make sure that it’s suitable for you. It’s also from a lens of if there is a history of an eating disorder or a disordered eating.
Jess (16:10.146)
But the angle that it does not come from is if you are an elite athlete or if you are someone training like an athlete and they’re training at a high intensity most days, maybe intermittent fasting isn’t the right thing for you. They may, isn’t the right thing for you to be doing all of the time.
The other place, and look I haven’t seen this happen too much, is in someone with a really high energy budget that is still developing. So definitely like from an adolescent perspective, but similarly from this whole elite athlete perspective like…
for I’m going to use a male athlete here as an example, like up until around 22 years of age, they still are in some level of development. So anyone with that really high energy budget, intermittent fasting is just not something that I would be recommending. And I’ve definitely seen it and I’ve definitely heard it with some of my like high level junior athletes like that 18, 19, 20. And they’ve heard about intermittent fasting and
they might not be good at breakfast and they’ve just decided in their head that that’s what they’re doing. But again, diving deep, it’s like this isn’t actually supporting your performance. If anything, it’s actually undermining it.
In instances where I may use it with an athlete is someone who is what would be considered like an older athlete. So depending on the sport, and look in this example I am referring to elite athletes. So there have been say like early to mid 30s I’m thinking some AFL and NRL players I’ve worked with and we’ve worked out on different days on very strategic, very specific days that might be something that they use like once a week.
Jess (17:59.408)
But in most instances, it’s not necessarily about intermittent fasting, it might be more about pushing breakfast back.
which would still be somewhat of a time restricted eating, but it’s not this mindset of I’m skipping breakfast, I’m not having breakfast. Because what we know for someone who is very active, like an elite athlete or someone who trains like an athlete, that for 24 to 48 hours after an intense workout, your ability to recover, your ability to, it’s called muscle protein synthesis, which is the pathway for gaining and maintaining lean mass is elevated.
If you’ve had a really hard workout the morning before or the night before and then the next day you’re fasting, you’re missing that window of opportunity to maximise that recovery there. And what I often find is that most people are doing it because one, they’ve heard it and they think that it’s good for them and their performance, or two, they’re using it to manipulate their energy intake and potentially drop some body fat. Which when you dive into that conversation, it’s like, okay, well if that’s what you’re doing, let’s find a way.
Solution that gives you that outcome, but that is in jeopardizing your recovery and now referring to this AFL player Who was one of the inspirations for today’s conversation? Talking to him Short term he felt it was good. You know he was managing his weight He was feeling quite good, but after doing this for a few weeks or a few months particularly in season when games are happening He was then just having this week or two where he would just feel totally depleted
Jess (19:39.672)
really low energy and it was these little windows of recovery which he wasn’t optimizing because he was fasting that were jeopardizing that. So I know there are a lot of people here who are athletes or who want to eat like an athlete or who train like an athlete. So I really wanted to have this conversation today. Might be a little bit of a spicier one because I am
Jess (20:10.252)
I am pro-fasting for the right circumstances and the right people but I really do see it as have you earned the right to use this tool? Are you an advanced user who was passed through the beginner status of learning how to eat to just optimize your quality of life for now and for the future? Have you then dialed in things in even further and are we now looking at this tool? Now look this isn’t to say that you know for the some of the people in
the study that it can’t be used. Obviously we’re starting to see research where in certain populations, so for example, these overweight women, which in the Dr. John Hawley study, which saw benefits from time restricted eating and also doing a few high intensity interval training sessions a week.
Fantastic, great. We can use this as a tool, but we still need to learn how to eat. We need to, we need to be looking at are we preparing the majority of our meals? Are we eating the majority of whole foods? As I’ve said before, it is that quality piece and we cannot cheat quality. Quality of the food that you are eating is the number one priority for every single person.
Jess (21:37.482)
The next point I want to make is the types of clients that I do regularly use fasting in some capacity with. And these tend to be more of my corporate clients. So they might be whether they’re an executive, whether they’re a leader, whether they’re a founder, whether they’re just a corporate professional who regularly finds that they are dining.
they are entertaining clients, having meetings, and there is that less of control over what they are having. Now, I do caveat that because I do believe no matter what the circumstances are, you can always make the best choice. So that’s the first point I want to make there. But in saying that, in saying that we know that when we eat out that…
it is going to be different to the types of foods that we would cook and prepare for ourselves at home. So the types of clients that I like to use these kind of strategies with are clients who have learnt the basics, clients who have grasped fundamentally how to eat, how to integrate it into their life, how to enjoy it.
how for it not to feel like punishment, I really do feel like there is this heavy misconception that eating well is.
boring and bland and not enjoyable. Absolutely not the case. If you’re doing that, you just haven’t learned how to balance your meals, eat with all the elements, flavor it with the right foods. You haven’t learned to enjoy food. The other thing is if you’re eating out often or you’re eating takeaway, and obviously they’re adding a lot more things to what we add at home, is changing the flavor profile. So even just from a taste bud perspective, when we start to remove these types of foods, not forever, but we reduce them. When we start to eat more whole foods,
Jess (23:29.392)
we start to take responsibility of our food, then yes, the flavor profile might change, but we do adapt to that. So that’s the other point, but it should not be punishment. So it should not be bland. It shouldn’t be punishment. So the types of clients are those who’ve learned that. They’re looking to manipulate their intake. They might be looking for some longevity benefits, but they’re the types of clients that have the foundations in place.
The other type of client is again someone who’s still grasped all of that, but they are that busy professional, busy corporate.
meetings, eating out, entertaining clients, traveling domestically or internationally for work. And there are things that are just a little bit more out of their control. It’s still important that we assess what their life looks like when they train, when they can use it, because when it can be challenging to intermittent fasties, particularly those people that exercise in the morning at a high intensity, and then they wanna wait and delay their meal. What you will find is there is a two pronged kind of consequence of one,
recovery and
to there can then often be that flow on effects later in the day where the energy is crashing, their appetites a little bit all over the place, they might be craving sugar and that’s often a consequence of what’s happened in the morning. So it can be hard for someone who trains in the morning to push back that meal, it may not be suitable. Most instances if it’s a high intensity it’s not. If it’s a low intensity workout, a walk, Pilates, yoga, something like that,
Jess (25:09.116)
at a higher intensity whether we’re doing like a cardio or a strength training workout, we want to be getting that nutrition in within the hour. So in that instance, you know, if we are looking to implement something like this, it might be more time restricted eating. It might be looking at when they have their first meal, when they have their last meal and can we get it within that 10 to 12 hour window.
Jess (25:32.918)
There’s no… yeah.
Jess (25:39.5)
Um…
Jess (25:42.698)
So I hope today’s episode has been helpful. I hope it’s been insightful. I hope it’s given you an insight into how these kinds of tools can be used. And I hope it’s made you reflect, is this something I’m doing? Should I actually be doing it? Is this actually helping me? And look, if you were someone who…
is having those questions, please feel free to reach out if you’re wanting to work with someone in that kind of capacity or, if you’re wanting to work with someone in that capacity to see if this is a strategy that you should be using.
Jess (26:23.784)
oooo
Jess (26:33.406)
And I think the main thing here is wanting to better yourself and wanting to maximize your energy, maximize your performance, maximizing your longevity is amazing. What I want to do though is, what my aim for today was to have a bit of a real conversation and just…
make you aware of where this type of thing fits in. And it’s a little bit of an accountability session, I guess, to be honest, because as I said, I’m either seeing, not all the time, but I’ve seen it enough to wanna.
cover it in an entire episode. I’ve either seen really motivated, high level, high performing individuals like elite athletes trying to use these strategies when it’s not actually supportive to what they are trying to achieve, even though in the short term, they may think it is. And then the other situation that I am seeing it is that it is an excuse or a bandaid for poor lifestyle choices, which is just.
If you are a high performer or you want to be a high performer or you just want to live your best life now and into the future, then let’s not make excuses. Let’s not cut corners. I know we’re busy. I know we’ve got a lot of things happening, but…
Jess (27:55.834)
It’s still not an excuse to not learn how to leverage one of the most important and powerful levers that you have total control over every single day, which is what you eat, which is what you eat.
Jess (28:12.802)
Thank you for joining me for today’s episode. If you’ve liked it, I would love for you to share it with a friend or someone who is interested in this space. If you haven’t yet hit subscribe, please do that. It really helps the show and it also helps make sure that you don’t miss an episode when it lands.
For those of you who have left ratings and reviews, I’m so grateful. And if you haven’t, if you could take 30 seconds to quickly do that on Apple or Spotify, it really means so much. It helps the podcast reach more people. And to be honest, I just love reading them. I do a lot of solo episodes. So to hear and know that people are listening, that they’re finding benefit and it’s adding value to their life.
just makes me feel really great about doing it as well. So on that note, I’ll be back again next week for the last episode of season one. I can’t believe we’re at 20 episodes already. I will be taking a short break for about a month and then I’ll be back with brand new content. But until then friends, I hope you all keep staying at the top.