Keto vs High Carb vs Even Macro Split – What is the TRUE energy intake of your favourite diets?

It’s been drummed so hard in to us over the years that fat loss always comes down to creating a negative energy balance. In plain terms, your energy in has to be less than your energy out.

As you will all know if you’ve read anything I have written in the past, this is not always as simple as just counting some calories. And there are MANY, MANY other factors that come in to play that govern whether you will store or lose fat.

One factor that has been discussed repeatedly when looking at energy equations is the Thermic Effect of Feeding, or TEF for short.

The Thermic Effect of Feeding basically means your body uses energy during the digestion process to extract energy from the foods you eat. Some of which is lost as heat. Different macronutrients operate at different efficiencies.

For example, if you eat 25g of Protein, this works out to be about 100 calories. BUT, protein only operates at about 70% efficiency, meaning 30% of those calories are LOST AS HEAT. So, the true calorie intake is actually 70 calories.

Compare this to Carbohydrate, which operates around 85% (average), and in the same 100 calories, you end up using 85 calories.

Fats operate at a much higher efficiency rate of 97%, which means that only 3% of the calories you eat are lost as energy. In the same 100 calories ingested in the examples above, this means you are actually using 97 of those 100 calories.

Thermic Effect of Feeding:

% Lost as Heat
Protein 30%
Carbs 15%
Fats 3%


True Energy Intake:

True Energy Intake from 100 Cals
Protein 70cals
Carbs 85cals
Fats 97cals


As you can see from this, NOT ALL CALORIES ARE CREATED EQUAL. And you can’t simply just count calories if you want to compare the effects of different diets.

If you want to maximise fat loss, one of the things you should be focusing on to help you create your negative energy balance is to MAXIMISE the THERMIC EFFECT OF FEEDING.

The problem is, you don’t eat just one of the macronutrients in a day, but a combination of all three.

The question then becomes, what is the best ratio of macronutrients to maximise this thermic effect?

Below we’ll compare 3 popular diet / macro ratio’s to see which is best for maximising the TEF.

For simplicity sake, we have chosen 1500 calories. The different % breakdown of 3 different popular macronutrient breakdowns are detailed below.

Three Diets with the SAME calories

Energy Intake Protein Carbs Fats
Even Macro 40% 30% 30%
1500 600 450 450
Keto 20% 10% 70%
1500 300 150 1050
High Carb : Low Fat 15% 60% 25%
1500 225 900 375


Now let’s compare what the TRUE energy intake for each of these 3 diet ratio’s are once they have been adjusted for the TEF.

TEF ADJUSTED DIETS (the more energy lost the BETTER)

Even Macro
1239 420 383 437 LOSS
Calorie Difference 261 17.4%
1356 210 128 1019 LOSS
Calorie Difference 144 9.6%
High Carb : Low Fat
1286 158 765 364 LOSS
Calorie Difference 214 14.3%


The TRUE Calorie Intake:

Even Macro’s: True Calories = 1239cals

Keto: True Calories = 1356cals

High Carb : Low Fat = 1286cals

From the above, you can see the TRUE energy intake from an Even Macronutrient Split is actually 1239 calories from the total of 1500 ingested. This is a LOSS of 17.4% as heat.

For the Traditional Keto diet, you only lose about half as much as heat at 9.6%. Your true energy intake out of your 1500 here is 1356.

For the High Carb : Low Fat diet, 14.3% is lost as heat, leaving you with 1286 calories out of your original 1500.

The KETO diet is actually the HIGHEST true energy intake out of all 3!

So what gives? How can keto in some instances help you to lose MORE fat than the high carb version (I’m not going to go in to detail on any keto debate here, but yes there is a lot of research showing this). The truth lies in the fact there are OTHER factors involved with fat loss than just the Thermic Effect of Feeding helping create a negative energy balance. Most of which I have written in detail about in the past.

What Does It All Mean?

When looking to create a negative energy balance, there are different ways you can improve on this EVEN WHEN THE CALORIE INTAKE IS THE SAME.

In the above example an EVEN MACRO SPLIT is actually the MOST EFFECTIVE in maximising the TEF and creating the OPTIMAL TRUE ENERGY INTAKE.

The best diet ratio that does this is an even macronutrient split consisting of

  • Maximising TEF
  • Maximising Fibre Intake
  • Optimising Hormonal Environment

If you want to maximise a negative energy balance AND create an optimal environment for fat loss, you need to maximise the TEF AND optimise the hormonal environment for this to operate in.

Obviously your total macronutrient intake and maintenance calorie intake for the day is an individualised calculation. But these are the principles you can use to optimise fat loss at any given calorie calculation.

For help in calculating the most effective fat loss macronutrient calculations for your own diet, contact The Courage Corner on