A Quick Primer on Energy, Calories and Macronutrients

Updated: Mar 17

Weight loss and gain really boils down to one, simple-to-understand, concept – energy balance.

It's effectively how much energy we use up vs how much energy we consume. Consume more than you expend and you create an energy surplus. This surplus is then stored in the body and results in weight gain.

Expend more than you consume and you create an energy deficit. This eats away at the stores of energy in your body (to catch up to that expenditure level) and results in weight loss.

An easy way to understand this is to visualise a water balloon, with a leak. Imagine you’re filling that balloon up, and the leak is tiny. You’re able to put in water faster than it leaks out – and the balloon gets bigger – and the opposite holds true when that leak is huge.

Now – energy in itself is measured in what we call, calories (actually Kilocalories but lets not get over complicated). I’ve included a definition at the bottom of this article, for those that are curious.


When we consume calories through food, it comes in the form of Macronutrients (you might have heard them referred to as ‘macros’), of which there are 4. These are:

1. Protein

2. Fat

3. Carbohydrate

4. Alcohol (though calling this a nutrient is odd, as there’s virtually no nutritional value here)

These all have different purposes, benefits and drawbacks – but the first 3 are 100% necessary for survival and to keep our bodies happy and healthy. I delve into these briefly below and will do a more detailed post on each in the near future.


There’s 4kcal of energy for each gram of protein.

Protein is used to help grow, build and repair tissue in the body (e.g. helps grow & repair your muscles), aid in creating essential hormones and provides support to our immune systems.

Basically – if you want to grow muscle (which can aid in weight loss), you need to be consuming sufficient protein.


There’s 9kcal of energy for each gram of fat.

Fat got itself a bad rep over the years from the Media/Government’s campaigns suggesting fat is the reason for obesity – this couldn’t be further from the truth because, as we remember from above, fat isn’t inherently causing weight gain – an excess of energy causes weight gain.

This means that, in theory, you can eat all the fat you want (though I would always recommend a balanced diet) and still lose weight, provided you don’t consume more than your body can use.

Don’t fall for the whole ‘fat is bad for you’ , ‘fat makes you fat’ hysteria – trust me when I tell you you’re allowed to keep eating fat. Don’t give up on that bit of garlic butter on your steak, or actually creamy ice cream.

Anyway, I got distracted. What does fat do?

Fat is needed by the body to assist with the absorption of vitamins & minerals, to protect our internal organs, promote cell growth, produce hormones and keep you warm.

Also – and this is important – focus more on unsaturated fats in your diet – they’ll reduce that bad cholesterol (more on this in a future post).


There’s 4kcal of energy per gram of Carbohydrate (same as protein).

Carbohydrate is our body’s preferred source of energy, and a source of energy it can tap into quickly. Part of what we consume gets converted to Glycogen, which is then stored in our liver and muscles before being used for energy.

This is important because it means carbohydrates actually help to preserve muscle, by providing the body with an energy source to use, distracting it from using muscle for energy.

Lastly, they promote digestive health. This particular element of carbohydrates is called fiber.

Fiber (the soluble kind) helps you to make bowel movements more easily, and that in turn helps to flush toxins out of your body more efficiently. It’s also closely linked with being able to reduce the risk a variety of diseases – so don’t let the ‘carbs are bad’ crowd get in your head.

Also - some carbohydrates aren’t actually digestible – but again, we’ll touch on this in future posts. Let’s not overwhelm with detail just yet.


There’s 7kcal of energy per gram of alcohol.

There’s virtually no, scientifically backed, nutritional benefit to this, but I’d be remiss to not include it in here as it’s a part of a lot of people’s lives and so definitely contributes to your energy balance.

So that’s about it!

You’ll see a lot of fad diets out there that promote reduced fat or reduced carb or reduced protein – my recommendation is to find something that is healthy, balanced and non-restrictive – that’s the diet that you’re most likely to adhere to.

Carbs, Fats, Proteins – you need all of them to survive, so there’s no need to be afraid of any of them.

All that matters is that you control your energy balance in line with your goals, and make sure you're getting enough of the main three Macronutrients. (don't worry about alcohol).

If you’re still a bit confused about which way to go and what to do or struggling to understand – I’ll be doing a few more posts in the future on these topics and I hope they clear things up.

And – if you want answers/guidance a bit quicker or just some help getting started on your weight loss/gain goals, you can sign up with me for a bit or just have a quick Skype call.

Drop me an email on dinesh@dljfitness.com if you have any questions or do want to sign up, and I’ll get back to you pretty quickly!


DEFINITION OF A CALORIE: The energy needed to raise the temperature of 1 gram of water through 1 °C

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