Aidan:

Hello and welcome to episode 242 of the Ideal Nutrition podcast. My name is Aidan Muir. And I’m here with my co-host Torwen Eerkins. This episode is about whether whole food diets lead to greater fat loss. And for me, this was prompted by an Instagram post. They mathematically broke down the net calorie difference of two diets. They were technically the same calories. However, the total theoretical deficit differed by the end of the day.

And this is a concept I’m very familiar with. Still, I’ve never seen anyone put numbers on it. I thought that was a cool idea. I wanted to talk about that. For this one, we’re doing a bit of both. We’ll cover the direct and indirect potential differences. We’ll compare whole food diets and less whole food diets.

Torwen:

So let’s talk about what we consider a whole food diet. A whole food diet emphasises mostly foods that are minimally processed. So, they stay close to their natural form. We’re talking lots of vegetables, fruits, whole grains, legumes, nuts, seeds, lean protein sources, and maybe dairy. Or alternatives with minimal additives.

Aidan:

From a macronutrient perspective, in many cases, they’re higher in protein. They’re also higher in fibre as well. You can also make an argument. If they’re closer to a natural state, they can be more difficult to digest. You could view that as a bad thing sometimes. However, in terms of fat loss, it might be beneficial. Because you could theoretically absorb fewer calories. You could also feel fuller for longer. There’s a lot in there too.

Torwen:

So, how could this lead to more fat loss? So, should we chat about the indirect effects first?

Aidan:

I reckon we’ll start with calories in, calories out. I know it’s very simple. However, we’ll go through it quickly. Obviously, every day we eat a certain amount of calories. Every day we burn a certain amount of calories. If we consume fewer calories than we burn, that typically leads to fat loss.

That happens because calories are a unit of energy. And we get them externally from food and drink. We also have internal stores in our body. And because it’s a unit of energy, it cannot just disappear. It also cannot come out of nowhere. So theoretically, if we physically utilise more calories than we take in, it has to come from somewhere. It comes from our internal sources. That includes muscle, fat, or glycogen. Ideally, we’re holding on to all of our muscle.

Therefore, it most likely comes from body fat. That is a fuel source of energy. A kilo of body fat has around 7,700 calories. As I’ve said, the body’s partly made up of calories. So, for this to have an indirect or direct effect on fat loss, it has to play a role within that understanding.

Torwen:

Absolutely. So, you need to be in a calorie deficit to lose body fat. Indirectly, you’ve touched on a few of these already. But by having a whole foods diet, you’re likely increasing satiety. You’re also having more fibre and more protein. Protein contributes most to satiety. Fibre helps increase fullness. It increases the size of the meal. It does that without massively increasing calories. This can help reduce passive overeating. It also means you’re not eating as much if you’re more satiated.

Aidan:

I also think people have less desire to eat. The food industry is very good at making food taste nice. In a more natural form, it’s often less appealing to eat. There are fewer options as well. You’re quite literally excluding a lot of the options available. It also reduces convenience. A piece of whole fruit is less convenient. It’s less convenient than something pre-done. Many people end up in a deficit due to that. That’s theoretical common sense.

But there is a bit of research directly looking at this. The classic example is a study by Kevin Hall. Where they looked at processed versus unprocessed food. It was an ad libitum study. Food was provided, then they measured how much people ate. The processed food group ate more. The unprocessed food group ate less.

And you could criticise it by saying they got nicer food. Fair enough if you want to go that route. However, it seems clear. If you eat to a comfortable level of fullness, you won’t eat as many calories in most cases. That applies when you’re following a mostly minimally processed diet.

Torwen:

And this was without deliberate calorie restrictions. They were told they could eat as much as they liked. The meals were provided for them. It showed that whole food diets reduce spontaneous energy intake. That likely happens for the reasons we mentioned.

Aidan:

Now let’s talk direct stuff. And this is where it gets even more interesting. Indirect stuff was pretty common sense. This one is different. If all calories are stable, does it still outperform? The answer is yes. We’ll talk through why. One example I point to is calorie absorption. The classic example is nuts, specifically almonds.

We tend to absorb about 70 to 80% of the calories. There is individual variation. But that is the average. Theoretically, if you have 30 grams and it says 160 calories, you might absorb about 120 instead. That is a factor. You could have the same total calories. Yet you could absorb less from one thing than another.

It applies to other foods too. I use almonds as the example. This applies to many foods in the whole food category. Another one I want to talk about is fibre. High fibre diets reduce calorie absorption. On average, it’s more than a hundred calories per day.

I was contemplating going down the rabbit hole. Why does this happen? Is it worth going down there? I do think it’s interesting. If you’re interested, here it is. If you’re not, you’re still going to get it anyway. With soluble fibre, you can get a gel-like effect. That can create a barrier to digestion in the intestine.

So, some food can then go through undigested. There’s also bile acid reduction. That reduces fat absorption. With insoluble fibre, transit speed increases. That reduces contact time with the intestine. That reduces digestion. That’s how you get a slight reduction in calorie absorption.

Torwen:

Another one that might fit here is the thermic effect of food. And that total daily energy expenditure also contributes to fat loss. Foods higher in fibre and protein have a higher thermic effect of food. That could increase daily energy expenditure. That means you’re still in a deficit, indirectly.

Aidan:

Yeah, and the standard numbers we’ve got are like this. Fat is about 0 to 3%. That’s the increase in energy expenditure from fat calories. For carbs, on average, it’s about 5 to 10%. I think that one would scale based on the type of carbs. For protein, it’s about 20 to 40%. Protein is clearly the highest thermic effect of food one.

Now we’re going to do a practical example. We’ll use two 2,000 calorie diets. And we’ll look at different features and what differences we’d be looking at. So, let’s say you’ve got a high-protein, low-fat diet. Specific macros. Nearly 200 grams of protein. Around 180 grams of carbs. Around 55 grams of fat. If we measured the thermic effect of food, we’d see about 300 calories. That would be the increase in energy expenditure. Let’s say you do the opposite.

Low protein, high fat. Let’s say 75 grams of protein. I hate reading a number that low. It is what it is. People do that. 200 grams of carbs. 100 grams of fat. Quite high fat. Low protein. That equals an average 150-calorie increase in energy expenditure. That comes from the thermic effect of food. So it’s about half. It’s already a 150-calorie difference. You could use different numbers. You could go in between. The point is, if you went noticeably different, you would see a difference. Net difference so far is 150 calories.

Then let’s do high fibre versus low fibre. That adds roughly a 100 calorie difference. Now the net difference is 250. You could go further. You could do super minimally processed versus super processed. That would be even more. The point is even for a 2,000 calorie diet, the difference could be 250 calories. If you went to a 3,000 calorie diet, it would scale more. Is this huge? Not really. Still, you can stack on the indirect benefits. That can make a difference overall.

Torwen:

And if it’s 250 calories consistently every day, it adds up. One kilo of body fat is 7,700 calories. That’s about an extra quarter of a kilo weight loss per week. That could be significant long-term. It also comes with chronic health benefits moving forward. Should we talk about advice? Or practical takeaways and recommendations?

Aidan:

Absolutely. There are so many easy steps you can take. I put up a post on Instagram today. It said 80% of the population doesn’t meet standard fibre recommendations. There are easy changes. Eat more fruit. Eat more vegetables. So on and so forth. Even in the fitness community, people often have relatively good diets.

Still, people can get swung away from this direction. That happens when there’s a big focus on macros or tracking. Many people avoid fruit. They don’t want to use carbs on fruit. They would rather save that for dessert later. Suddenly that moves them towards more processed foods. It moves them away from this.

It also reduces their micronutrient intake. Then there’s more protein bars and protein powder. I’m not opposed to those. However, you can see the logic. Someone could have a good diet from a macro perspective. Yet they could miss heaps of whole foods.

Torwen:

And that’s where balance comes into play. I think we’ve got similar ideas in that if you aim for 80% whole foods and 20% more processed foods, you get many benefits. That includes hunger management, fibre, quality protein, and healthy fat sources. It exists on a spectrum. And it doesn’t need to be 100% whole foods. It can be majority whole foods.

Aidan:

Yeah, absolutely. I don’t know if you do this. With a lot of clients, if they’re already tracking macros, I suggest a break. I get a lot of people to do a two-week break from tracking macros. I give them a plan structure based mostly on whole foods. It’s like building habits I want them to do. It’s not because I’m opposed to tracking. I like tracking in many situations. It’s case by case. I won’t use it in disordered eating situations.

My logic is simple. If we went two weeks without tracking, it’s easy to go back. What I often find is this. If we don’t step away from tracking, not ideal habits stay around. Because tracking can be a safety net. People keep doing what they’re doing. They just use the new macros I give them.

Torwen:

If it adds up, they think they’re doing the right thing. Yet you want to get rid of some habits.

Aidan:

If I say, “Let’s do the plan for two weeks,” things change. Some things stick. Some things won’t. We focus on what worked well. We play around with what didn’t. Then we can add tracking later if we want.

Torwen:

That makes a lot of sense. Also, we’re talking about whole food diets for fat loss. If you’re an athlete with super high energy requirements, that changes things. You may need a higher aspect of processed foods. Otherwise, you’re eating massive volume each day.

This has been episode 242 of the Ideal Nutrition Podcast. We hope you enjoyed today’s episode. As always, if you did, we’d love a positive review. We’ll be back next week.