I’d like to talk to you about energy and calories. Some basics about calories or kilojoules – a calorie or kilojoule is just a unit of energy. Carbohydrates, proteins, fats and alcohol supply you with energy or calories, whereas vitamins and minerals don’t supply you with any energy. They are involved in energy-producing processes and metabolism of foods.

Let’s do a bit of a recap. When it comes to calories, we have the following:

  • 1 gram of carbohydrate gives you 4 calories.
  • 1 gram of protein gives you 4 calories.
  • 1 gram of fat gives you 9 calories.
  • 1 gram of alcohol gives you 7 calories


We need to look slightly wider than just weight loss. We need to look at the quality of the foods we’re eating.


So, you could see why, traditionally, diets that are seen to be high in fat are also seen to be high in calories. That’s how the low-fat diet came into play with regards weight loss, because if you’re eating lots of calories, you must be eating lots of fat? If you cut your fat down, then you’ll cut your calories down and then you will lose weight? We all know that this is true. Absolutely. You can lose weight by being on a low-fat diet. We know that you can lose weight by being on a low-carb diet, a low-fat diet, a diet where you have shakes, a diet when you do some intermittent fasting, a vegetarian or vegan diet, a Mediterranean diet. You can jump up and down and lose weight, but we need to look slightly wider than just weight loss. We need to look at the quality of the foods we’re eating. So, that’s your first lever, what we eat. Food quality is really important.

We also need to look at how the foods interact with your body and various conditions that you might have and how that can be sustainable long-term, because losing weight and regaining it a few months later is not the ideal situation. Once you get that weight off, you want to keep it off for good.

Now, I know that that doesn’t always happen and there are times in your life where you might pick up a few kilos, for example, during lockdown or during a holiday or during a very stressful time. Life’s not quite as simple as losing weight and keeping it off for good, but as long as you know the tools that will help you, then that’s really the ideal situation.



Energy In = Energy Out

I want to talk a little bit about energy in a more ‘sciency’ sense when it comes to weight loss. I know that you’re all familiar with this lovely equation – energy in equals energy out. If this isn’t balanced, then your weight stays the same.

When it comes to energy in equals energy out, I want to just talk about what that is. ‘Energy in’ is simply the food that you eat, whether it’s carbs, protein, fat or alcohol or a combination, that constitutes your energy in.

Your energy out is made up of three things:

  • Your BMR, which is your basal metabolic rate, and also called your resting metabolic rate. That is the amount of calories that is required for you to have basic functions – for your heart to beat, your nerves to transmit, your breathing, your existence, really. That is said to be around 1,500 calories for females just to survive. If you have ever been on Weight Watchers or some other diet and you’ve reduced to 1,200 calories or even lower sometimes, you don’t suddenly stop functioning. So, it’s not quite as simple as what we have learned in the past.
  • TEF – thermic effect of food. That is the calories that is required for your food to be metabolised, to break down. Interestingly, when your food breaks down, it actually releases energy, and it also requires energy for that to take place.
  • Exercise. This is the one that you can change the most. You can sit on the couch like a couch potato and burn no calories or you can train for an Iron Man and burn a zillion calories, and that will change your energy expenditure.

Even if you are metabolically well-regulated, and let’s say you want a low-carb diet or good quality whole food diet, you can still overeat calories. If you eat lots of fat it doesn’t magically disappear once you have satisfied your body requirements for maintenance. So, calories do count.


If you’re eating top quality food but you are not losing weight, it’s likely that you’re eating too much of that great food.


What can you do to still make progress without having to count calories?

The answer to this is very straightforward. You can cut down, pretty much. The more scientific way of doing it is to track your intake on an app or something like that for a few days. Let’s see how many calories you’re getting, and if your weight is maintained, then what we can do is we can reduce your calories. We can drop your calories and seeing where you sit, and that calorie reduction of around 500-800 calories will hopefully mean that you will lose some weight.

  1. No snacking

So, the best thing to do is to not snack. Your morning tea, your afternoon tea, your after dinner snacking – those are just extra calories. It doesn’t matter if you get it from ‘healthy’ sources, like salami or cheese, or from chocolate, it still is calories. A snack might be between 200-300 calories.

  1. Smaller portions

If you don’t want to count calories and you’re used to eating a big plate, you can just make it smaller. Make your piece of meat smaller. If you’ve got starchy vegetables, you might make that smaller. Make your breakfast meal a little bit smaller. If you go out to a restaurant for a treat meal, you can just make it smaller or order an entree rather than a main meal.

  1. Watch the calorie intake in your drinks

This is where calories absolutely catch up to people. Sadly, alcohol is very, very calorific, but that is one way that you can address your total calorie intake without necessarily having to count your calories.


If you’re consistent and you still not dropping weight, it might be that you are going through a really high stress period in your life.


Your stress hormones, your cortisol, your adrenaline, your interaction of your hypothalamic-pituitary-axis or your stress axis, your reproduction axis, your physiology, are working against you to prevent you from losing weight. That is a very real issue for some people. So, a lot of the time when I talk to people about calories and changing their diet and then not losing weight, we look at stress and mindfulness. Often, when people address it, they get some good outcomes.


Read more

Do calories count? Dr Caryn Zinn and Prof Grant Schofield explain.

Learn more

Take your nutrition knowledge to the next level. Dr Caryn Zinn is the lead instructor in the Certificate in Advanced Nutrition and the short course PK204: The Science and Practice of Weight Loss.