Time to put this to bed guys.

I will not over complicate this and will do my utmost to not oversimplify it either….

What I will do is start with the current beliefs of many/most ‘Nutritionists’ out there.

So here goes…It is well understood that carbohydrate causes an increase in insulin, the hormone needed to enable your body to absorb and use glucose (sugar derived from carbohydrate) for energy.

Insulin is anabolic, meaning it encourages muscle growth. However, it also encourages storage, specifically fat storage if consistently elevated.

And THAT is what all of the media and Nutritionists out there have latched onto. Insulin = fat storage and carbs = insulin…so it must be right.

The problem is that the logic is sound and the science kind of supports it. However, some evidence isn’t conclusive evidence, and that is where ‘real, hard, evidence based and robust science’ comes into it.

So, it makes sense to go to the gold standard of research when it comes to identifying what macronutrients are actually responsible for fat gain. Enter… Metabolic Ward studies.

Metabolic Wards are the posh word for a room, a tightly controlled and regulated room however, that enables researchers to monitor the exact calories and macronutrients (protein, carbs and fat) a subject (person) consumes. During the time in the room, researchers will also monitor the calories they expend as well as monitoring body composition throughout the 2-3 days one might spend in there.

There were 2 prominent and relatively recent Metabolic Ward studies, one published in Cell Metabolism Journal in 2015 and the other in the American Journal of Clinical Nutrition in 2016.

The researchers for both (Hall et al. 2015) ensured that the subjects in the room had a steady, controlled intake of protein over the 2-3 days, and ensured that one person consumed low carbohydrate and high fat, whilst the other consumed high carb and low fat.

The Result…

The amount of total fat loss was the same for both low carb and high carb diets.

The Conclusion…

It isn’t the composition of the diet i.e. quantity of carbs or fat that matter most when it comes to fat loss. What really matters is total calories.


And it’s a big however…this doesn’t mean someone should indiscriminately eat 100% of their calories for the day from carbs because cake, donuts and sweets are all carbs, right? Just because their calories in are less than calories out doesn’t make this an acceptable diet when trying to lose weight! A variety of protein, carbs and fat are needed for long term health and wellbeing, that’s a given.

That said, it does go to show that carbohydrates, despite the chastising, are NOT solely to blame for gaining fat. That’s like saying carbs are all that’s to blame for diabetes…that’s simply not the case either!

Check in for tomorrow’s Daily MANtra where I quash the myth that carbohydrates are to blame for the Diabetes pandemic we now face.


Hall et al, (2015). Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity. Retrieved https://www.ncbi.nlm.nih.gov/pubmed/26278052

Hall et al, (2016). Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. Retrieved http://ajcn.nutrition.org/content/early/2016/07/05/ajcn.116.133561.abstract

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