Hello, and welcome to The Ideal Nutrition Podcast. I am Leah Higl, and I’m here with my co-host, Aidan Muir. And today is part two of our three part series all about nutrition for fat loss. In part one, we discuss the concept of calories in versus calories out, how to figure out how many calories you need for fat loss, and just a bit of troubleshooting as well. And then today, we’re going to actually cover why people might report being on low calories and that not working for them. That’s something we commonly come across. We’ll go over that in detail. We’ll go over protein intake and its effect on body composition whilst you are going through a fat loss phase. We’ll go over low carb versus low fat for fat loss, and then also briefly touch on how hormones play a role in fat loss as well, although we have done a full episode on that.
We’re going to start with why do people report low calories not working? And I don’t like talking about this too much because partly it’s just not… It’s a negative topic. It is a negative topic. I don’t really like talking about it, but it is something that needs to be addressed because understanding this concept takes a bit of a hand break off when you’re trying to lose weight or lose body fat. If you think going too low calorie could prevent you from losing fat, if you aren’t losing fat, you have a question in your mind being like, am I on two high calories or too few calories? Understanding that it’s never too few calories is helpful just because it means, okay, that’s not the issue. I know that if I did want to lose body fat, I’d have to even reduce calorie and tech or increased energy expenditure.
Why do people report this occurring? The starting point is that it never happens in the research where all the meals are provided. I like to use that as a starting point because it’s like, this isn’t just a couple of studies or small sample size or anything like that, we have a lot of research on this. In the research, we have a lot of research where all the meals are provided. Every time people are put onto low calories in a controlled environment, weight loss happens like crazy. There’s countless examples of this. It’s like we know this just factually, that low calories equals weight loss. That doesn’t mean low calories is a good idea, but we know that it works for just solely looking at weight loss.
Why does it happen in the real world? I don’t want to speculate too much because there’s a variety of reasons that could happen, but one of the simplest ways I can phrase it is in the real world, not everything is controlled, and we also don’t see everything. I don’t want to speculate on individual cases because a friend could say, “Hey, I was eating 800 calories per day and didn’t lose any weight. Why did that happen?” And it’s like, well I wasn’t there. I didn’t-
I don’t know the details. I don’t want to be speculating and being like, “Well, what I think is happening is you’re eating more calories than you’re saying,” or anything like that because it’s like I wasn’t there; I don’t know what happened. Whereas in the research, it’s like, well, every meal was provided they had, that this is the outcome. As a broad statement, it’s basically being like either energy intake is underreported or energy expenditure is over-reported is what is typically happening in these cases.
And as a starting point, I want to touch on is that often it is completely unintentional, misreporting. A study that I really like to talk about in reference to this is a pretty old study, but they got people who had been self-reported to be diet resistant, as in they had tried to have 1,200 calorie diets multiple times about losing weight. And they followed them and then did a 24 hour recall on them to… They measured what they ate on that day, and then they measured what they said they ate. And what they said they ate came out as 47% less calories than what they actually consumed. That’s a really interesting starting point because it’s like, well, say they thought they were eating 1,200, they were eating 2,400 based on that kind of mathematics.
But the thing that stands out to me with the unintentional aspect is that nobody got within 80% of what they were doing when they said what they were doing. That’s where I come with it from the unintentional aspect being like, I truly believe in that sample size, there were people who tried to say everything they ate, but it didn’t line up 100%.
And then that’s obviously just a 24 hour period. In the real world, we have a lot more going on. Say I have birthday cake once every six weeks or something like that. If somebody asked me what I ate, I’m not going to say… Because it’s like-
Yeah, you wouldn’t mention that.
I wouldn’t think about it, I wouldn’t mention it. It’s also just we’d be here all day if we went through everything. Simply reporting doesn’t always line up with what is actually happening. But taking that out of it, I think one thing we can agree on with the model of thinking with calories in versus calories out is that, based on this model, if somebody ate zero calories per day for weeks on end, we can agree as a starting point that they couldn’t gain weight because the body’s made up calories. One kilo of body fat, as mentioned in previous podcast, is 7,000 to 8,000 calories. That couldn’t be stored if we don’t have colors coming in. Then the next step is surely we can agree that somewhere between zero calories per day and quote, unquote, “low calories,” the same logic would still hold true.
Then the next step is it’s like, if the low calories… Let’s use 1,200 calories or 800 calories or anything like that not leading to weight loss was to happen within the model of calories in, calories out and everything like that, which is a model that we know exists, the only way that that can possibly happen if reporting is accurate and everything like that is if the body has down regulated energy expenditure to the point that it matches it. But the body is always burning calories for a purpose. It doesn’t just burn calories for no reason, which means it can also only down-regulate so far.
One thing that I say to a lot of people is that body fat just sitting there burns around four calories per kilo per day, muscle burns around 12 calories, or lean body mass on average burns about 12 calories per kilo per day. You put that together… And I don’t want to get the math wrong here, but for an 80 kilo person it could be 800 calories, just those just existing.
And that’s not something that down regulates when we go into a calorie deficit or down regulates that much. Other stuff can dam regulate. Our heart rate can decrease, but it can’t switch off. Our brain can decrease its function, but it can’t switch off. We can breathe less, but we can’t just stop breathing; all of these kind of things. The body is burning calories for a reason, but it down regulates only so far.
And we see this in examples like Hashimoto’s and stuff like that where thyroid hormones are lower. That means certain functions are down regulated in the body, and that therefore reduces energy expenditure. But the highest reported cases that I’ve seen in the research is about a 15% reduction in total daily energy expenditure due to that. And they’re getting pretty horrific symptoms because, as I said, the body’s not burning calorie for no reason. In these cases where calorie expenditure is reduced, it is showing pretty horrific symptoms as well. Yeah, I’ve gone on for a bit of a ramble with that, but basically-
Yeah. I think it’s definitely worth talking about, though. And I think with everything on social media where we do have people saying… Nutrition coaches and whatnot do saying, “Oh, you just need to eat more calories. That’s why you’re not losing weight.” That’s something I see all of the time. And it adds confusion to this when usually what those people are talking about is that you are not eating enough usually to manage your hunger cues in regards to food volume. That’s a very different thing to actual calorie intake. I think everything you just ran through is super, super important to know.
Let’s jump into protein intake. Since the goal of fat loss is fat loss and not usually to lose muscle in the process, we’re really looking at wanting to retain as much muscle mass as possible. Calories control what we weigh. As an oversimplification, if the calories dictated that we lost, say, eight kilos overall but one version focused on muscle retention with a high protein intake and the other didn’t, then the body composition outcome at the end of the day would be different from that fat loss or weight loss phase. One version could, say, lose eight kilos of body fat and zero kilos of muscle. That would be a great outcome, if you lost literally no muscle and all eight kilos of body fat. To do that, you would have to have a nice high protein intake amongst other things.
But let’s say the other person does the exact same thing but not focusing on protein or muscle retention and they lose just five kilos of fat and three kilos of muscle. Looking at it from a fat loss perspective, one is clearly better than the other when we’re looking at body composition outcomes. The reason that is oversimplified is because muscle and fat do contain slightly different amounts of calories, though, so that is something to note. Technically the same size deficit would result in slightly different weight loss if we’re thinking fat loss versus muscle loss. But I don’t like to get too deep into that usually with clients. I think it’s simpler just to-
Yeah, I’ll add on to that because I don’t… This is helpful information, but I think it’s interesting to know exactly what we’re talking about with this. One kilo of fat, as we’ve mentioned… I don’t know if we mentioned this one; we’ve mentioned in the last one for sure, is made of about 7,000 to 8,000 calories. One kilo of muscle is made of about 1,200 calories, but it’s energetically expensive to create muscle. It takes about five times that amount of calories. That therefore means they both take about 7,000 calories, roughly, to create one kilo of them.
What about in a fat loss phase? If you’re in a deficit and you are losing more muscle and muscle’s only made up of 1,200, it is a little bit different. And I just prefer the simplified rule. I got this from bodybuilding.com, but a 500 calorie per day deficit results in one pound of weight loss per week, or fat loss per week based on the understanding that one pound of body fat is made up with 3,500 calories. Converted to kilos, I just say 7,000 to 8,000. Same kind of concept; 500 calorie deficit equals around half kilo weight loss per week, assuming most of it comes from body fat. Assuming you’re focusing on trying to maintain muscle and everything like that, you shouldn’t be losing that much muscle. And the concept still holds true. But that’s why it’s not that simple, because it depends on what you’re losing.
Yeah, 100% depends on what you’re losing. Yeah. But either way, a good protein target to aim for is probably somewhere between 1.6 to 2.2 grams per kilo of total body weight per day. If you are super lean or if your deficit is quite a large deficit, then you could go a bit on the higher end of that, so more like the two to 2.2 grams per kilo. But if you’re not very lean, if you are carrying more body fat, because your protein needs are based on how much lean mass you have, you can probably go on the lower end of that spectrum, maybe even 1.4 to 1.6 if you’re holding a significant amount of body fat, or have a lower amount of muscle mass to begin with.
At the end of the day, if you can fall somewhere in there, that would be ideal just from a fat loss perspective. If you’re in a deficit and your body composition goal is to lose fat, retain muscle, that’s where you want to sit with your protein intake. But at the end of the day, if those numbers are unrealistic for you, which sometimes they can be, like if you’re trying to eat 1,600 calories, sometimes getting 2.2 grams per kilo body weight of protein is not going to be realistic. Do what you can within that range, but just be consistent about it.
Completely agreed. The next one we’ll talk about is carbs versus fat. A lot of people talk about the merits of low carb diets, some people talk about low fat diets or just a calorie deficit in general. The honest truth is it doesn’t matter that much. Honestly, it just does not matter that much. Research has very, very clearly shown that in both controlled and uncontrolled settings, aiming for either a low carb diet or a low fat diet with the total amount of calories in protein matched comes out as the same outcome; they both result in the same amount of fat loss and muscle retention. That’s awesome to know because it gives us a lot of personal preference.
In amongst that, based on the research, I’m mostly of the opinion as well that there’s not even that much individual differences in terms of results as well in controlled settings and the personal preference. And stuff like that comes more down to what are you going to be able to stick to the most? And also what do you feel the best on? And everything like that.
I found it interesting that in uncontrolled settings, the outcomes come out very similarly, but that’s also very… It makes it easier as well because it’s like, okay, you literally can choose because it’s like, if in controlled settings where all the food was provided, it showed one thing, but in practice one thing would… the other thing was easier or whatever, then you’d still want to choose that. But it’s like, doesn’t really matter.
One thing that’s worth theoretically knowing is that carbs have four calories per gram, fat has nine calories per gram. That’s why in the ’80s and ’90s, everyone was talking about low fat diets and making out that that was a big deal and everything like that, because fat has more than doubly amount of calories per gram. But it doesn’t really matter that much in practice because of satiety and desire to eat. People on low carb diets, higher fat diets seem to end up eating a similar amount of calories anyway just because they might feel fuller per gram of fat, partly because it has more calories per gram as well.
Going one step deeper with this, the only thing I really don’t encourage is going super, super low fat for most people, just for hormonal reasons. It can have implications for testosterone, it can have implications for the menstrual cycle and stuff like that if you go really, really low. I don’t think many people need to worry about that unless they’re actively striving to cut out all fat sources from their diet, which it does happen occasionally, if people try to really clean up their diet and stuff like that and they’re just trying to cut out all fat sources. If somebody was tracking macros, anything above 0.4 grams per kilogram per day should be fine. Or a simpler way of saying that for most people is above, say, 30 grams of total fat or 40 grams of total fat would be a good metric for most people. Anything beyond that is mostly personal preference.
Yeah, I 100% agree. I think from a personal preference perspective, I prefer with a lot of my clients to take things very moderately on both sides and not go super, super low fat or super, super low carb unless they have a specific preference for it because we know that it just doesn’t matter or it might change day to day depending on food choices.
I think so, yeah. And particularly with plant-based arts and stuff like that, I just think it makes it easier knowing that it comes out the same. Because it’s like, well, it’s pretty hard to go low carb and be plant-based at the same time.
100%. What I run into is people wanting to be low fat on a plant-based diet, but being-
And that’s really hard to meet all of your micronutrient needs, because we know nuts and seeds and all those things are great, but also just making food taste good being very, very low fat is quite difficult. Yeah, personal preferences a big one there.
Next topic we are going to cover is how do hormones fit into all of this? We have discussed this in another episode in more detail, and that was episode 55. It is a huge topic that totally deserved its own podcast. If you are interested in learning more about how hormones play into say calories in versus calories out, definitely check that out. But we’re going to go over the cliff notes short version today.
Basically, the short of it is that hormones affect both calories in and calories out. Obviously there are so many hormones in the body that do all different kinds of things, but one really good example is a decreased thyroid hormone. I think we previously just talked about Hashimoto’s. That is something that can reduce your overall energy expenditure, so it’s literally changing that portion of the calories in versus calories out equation, so it’s already built in to that equation.
Another one would be your appetite hormones. Increased ghrelin could lead to an increased energy intake just due to being more hungry. That is something that we will often see people in calorie deficits, their ghrelin levels will increase and make them more hungry over time. That’s something that can affect the calories in portion of that.
I think it’s important to understand when we’re looking at calories in versus calories out that hormones literally play a role in both sides of that, so it can be a lot more in depth and confusing than people usually think. But we also see from a body composition perspective, even changes in things like the sex hormones, like testosterone and estrogen can have a really huge impact on your body composition. And that’s beyond calories in versus calories out. Hormones generally play a role in all of this.
Insulin is another one. Insulin gets talked about a lot in fat loss. And I know we have a lot of opinions and stuff to talk about around that, which we talked more about in episode 55. Insulin does play a role, but evidence from low carb versus low fat studies show the same fat loss when calories and protein are the same. That makes it clear that insulin is not the driving force behind all of this. It’s not something that’s going to make or break your fat loss phase.
Yeah, it’s a complex one, hey, because somebody listened to that podcast, they sent me a DM the other day. They listened to that podcasting, and they’re like, “Oh yeah, as you said, insulin’s not a driving force or anything like that.” But then they also sent me… I won’t name who it is, but they sent somebody who’s not the most reputable nutrition advice. But they sent that through, and they’re like, “But do you agree that insulin plays a role?” And I do agree that insulin plays a role, it is a storage hormone, and it is involved in storing body fat and everything like that, but I think the key takeaway from those low carb and low fat studies and everything like that with calories and protein matched is we probably just shouldn’t think about it that much.
There is that Kevin Hall study that showed that the same total calories, different carbs, different fats, and the low fat group had 21% more insulin throughout the study than the low carb group, but they lost a tiny bit more body fat than the low carb group. And it’s an insignificant difference, but it’s like, I wouldn’t even consider it being… Even though it definitely plays a role and everything like that, it’s just there’s so many other factors going into that that it would be very silly to focus on insulin much at all, really, basically if we’re just looking to lose body fat. I would focus on all these other variables that seem to matter a lot more.
Totally. This has been episode 80 of The Ideal Nutrition Podcast. Next week will be our final episode of this little nutrition for fat loss series, so hopefully you tune in for that. But otherwise, thanks for tuning in for this one.