The Calorie and Macronutrient Basics

As many of you will have seen, the 5-week challenge is well underway now. Or, you will have not seen, I suppose, because it's happening behind "closed doors"

Directing a large group of women, each with unique goals, starting positions, desires and lifestyles has been a challenge, as I expected it would be. I've learnt a lot from this process - as it's been my first experience doing something like this, trying to compact down 5 years of learning about nutrition, exercise and the psychology of weight loss as I made the journey myself and have maintained the lifestyle changes.

As the women in my challenge group now know - it is about so much more than understanding calories and macronutrients. Anyone who has been on a diet, lost an amount of weight, and then rebounded back to their habits from before can attest to this.

I would posit that the "obesity crisis" is one of psychology, above knowledge. Of course we want to know what to eat, but ultimately - you can lose weight eating absolute garbage if you so chose to. It's much much more than the macronutrient ratios you eat, especially when it comes to maintaining the change.

However, in the interests of sharing knowledge, I want to share the technical knowledge we went through in week 1 of the challenge - the basics. Because no matter where you're at with the mindset, the building blocks of "what to eat" are always at the forefront of everyone's minds. This kind of information is widely available all throughout the internet, so we're not reinventing the wheel here, but this is my attempt to condense hours and hours, pages and pages, many peoples opinions, down into one (reasonably) simple piece of reading about "the basics". Here we go.


The Basics

One of the most fundamental things most people learn when they first start taking an interest in nutrition is the concept of calories. The basic idea is that if your calories consumed are lower than the calories you expend, you will lose weight.

Whether this holds true in all circumstances is debatable – the numbers are approximations at best, and other factors can have a large impact on the math. But understanding calories is useful when it comes to wanting to make your own food plans.

Check out this calculator to see your BMR (basal metabolic rate – the calories you burn just by being alive) and your TDEE (total daily energy expenditure – the calories you burn in a typical day, which includes your activity on top of being alive) -

You can see the different estimates for your calorie expenditure at different activity levels. The general rule of thumb is that people should not eat below their BMR, on average, over time. That means one day, even a few days, below your BMR is okay, but consistently eating below that rate is not recommended. This is because that rate is the rate for supporting basic organ function – your brain uses a huge chunk of that. The buffer zone between your BMR and your TDEE is where you can cut down calories to lose weight. So if my BMR was 1700 and my TDEE was 2300, I could eat anywhere between 1700-2300 to lose weight. Remember these numbers are averages – you don’t have to eat that number every day, but making it average out over a week is smart.


The next thing to understand is where calories actually come from. They’re units of energy, contributed to by the elements in the food we eat. The three main constituents of our food are:

Carbohydrates: 4 calories per gram. These are the basic fuel source. There is NO minimum requirement for life i.e. you could eat zero carbohydrates.

Fats: 9 calories per gram. These form the basis for our hormone synthesis. There IS a minimum requirement for life, you could not survive eating zero fats.

Protein: 4 calories per gram. These are the building blocks for our body’s to repair and replace cells. There IS a minimum requirement for life, you could not survive eating zero protein.

Fat, carbohydrate and protein are the 3 macronutrients. (macro meaning “big”, micro meaning “small” – so micronutrients are the vitamins and minerals e.g. vitamin B12, zinc)

The reason that the calories per gram is important is because this determines the total calorie content of the food. Besides a few other bits and bobs (fibre, alcohol), nothing else contributes to the calorie content of the food we eat.

So, if an item of food has 10g of carbohydrates, 10g of fat, and 10g of protein, the calories in it will be (4x10) + (9x10) + (4x10) = 170 calories. This is really important. I won’t get into too much math where I can avoid it but this is the one piece of math I really want everyone to nail.

The reason this is important, for starters, is because a lot of nutrition labels are INCORRECT. Did you know people often don’t even check them? There’s no regulatory body checking every company’s nutrition label (at least, not in New Zealand – there could be elsewhere). If you look at smaller company’s nutrition info and add it up yourself, you’ll often find it doesn’t add up. Usually they’ve simply made a mathematical error. This is another example of how imprecise the art of calorie counting really is. Another situation where it won’t add up is if the product has a lot of fibre (fibre is partially digestible so the calories are hard to calculate) or contains alcohol (alcohol has calorific value of its own).

Macronutrient ratio

So now that we know the total calories of food are made up by the fat, protein and carbohydrate content, we can understand a macronutrient ratio.

The ratio describes the quantity of calories derived from each group. Remember fat is 9 calories per gram, while the other two are 4 calories per gram. So if we go back to the example of the food that is 10g carbs, 10g protein, 10g fat, what do you think the macronutrient ratio is?

40 calories from carbs, 90 calories from fats, and 40 calories from protein, so 40c:90f:40p This is then changed to add up to 100, so as to be easily compared i.e. 24c:52f:24p

The order of the macronutrients in the ratio can change, so just pay attention to which number refers to which macronutrient.

Counting calories

If you want to count calories, you will by default be counting macronutrients. As we just learnt, the macronutrients determine the calories – so you can’t count calories without counting macronutrients (even if you don’t realise you are).

There are many apps out there to do so – myfitnesspal is probably the most popular one people have heard of. Within the app you can set up your macronutrient ratio yourself, and set your calorie goal.

Choosing a macronutrient ratio

Everybody gets very confused about how to choose macronutrient ratios. Do I go 40p:20c:20f? What about 30p:10c:60f?

Honestly, at the end of the day, you need to decide what works for you. Fat is more satiating than carbohydrates. That means that although you eat less of it (because there are more calories per gram), it makes you feel more satisfied. That is why you can eat a low fat diet with mountains of carbohydrates and feel ravenous, despite the large physical volume of food you’re eating. However, some people enjoy carbohydrates and feel they don’t have enough energy without them, so they want to keep carbohydrates higher and fats lower.

The easiest hack I have found through experience is that as long as you keep your protein above 20 (ideally closer to 30), your personal choice of fat:carbohydrates does not matter. You can trial and error the other 70- 80% of the ratio between fat and carbs until you find what works for you. Basically, choose the ratio of fat:carbs that lets you meet your calorie goal the easiest with the least hunger.

Some example ratios:
25p:10c:65f (this is LCHF – low carb high fat – aka keto – which I use on and off)

30p:40c:30f (a common ratio for beginners)

40p:20c:20f (a common ratio for bodybuilders who try to eat a lot of protein – debatable whether it’s useful – as I said above, as long as you’re over 20, and ideally closer to 30, you’re fine)

You do not have to commit to the same ratio forever. I don’t even commit to the same ratio day to day. The key theme here is that where there is high fat, there should be lower carbs, and vice versa. The fastest way to GAIN fat is to eat a lot of fat and carbohydrates together. Keeping your protein part of the ratio high (30) stops that from happening. In theory, however, you could do 20p:70c:10f (i.e. very very low fat). The key theme remains – you don’t want high fat and high carb together (high is considered anything above 40).

How do you know you have the right macro ratio? How do you know you're eating enough protein? Ultimately, all you're trying to do is find the macro radio that allows you to reach your calorie goal with the least effort. If you're trying to gain mass, you want to get those calories in without it feeling burdensome. If you're trying to lose mass, you want to meet your deficit without feeling deprived and like it's too much effort. The arguments about how much protein you need are really arguments about satiety - as long as you're getting around 45g of protein a day you're meeting a safe minimum, and it's not difficult. Of course, we all want more than just survival, and for that reason I recommend a protein ratio of 20% minimum and ideally 30%. Beyond that, the semantics of what the ratio should be are entirely about personal preference and what makes each individual feel best and meet their calorie goal with the least effort, simple as that!

Further reading

To do list for beginners looking to get a better understanding of their calorie and macronutrient needs:

1.      Work out your TDEE. Choose a number of calories to aim for while you’re in a fat-loss stage that is between your BMR and your TDEE, if you want to maintain aim for your TDEE, and if you're trying to build, then add a bit onto your TDEE.

2.      Decide on a macronutrient ratio you want to start off trying (remember, protein above 20, ideally closer to 30, fat is more satiating but some people prefer more carbs, and don’t have high fat with high carb).

3.      Decide whether you want to count what you eat every day and enter it into an app, or whether you’d like to use the app to pre-plan 2-4 days of eating, write them down, and just cycle through them during the week as your baseline days to work from.

4.      Let go of the idea of “normal”. If we didn’t have the internet, we wouldn’t know how anyone else ate. Do you think people sat around in 200BC talking about their food? No, they ate what they had when they had it. 3 meals a day is a social construct. Let go of normal and find what works for you. Eat when you’re hungry, don’t make yourself eat when you’re not (as long as you’re prepared and will have food at hand when you do become hungry).