Energy Balance Series, Part 3: Are All Calories Created Equal?

Hi lovely!

It’s hard to believe we’re diving into the final instalment of the Energy Balance Series - time flies! We have already covered the power of small dietary adjustments, as well as the intricacies of energy expenditure. To wrap up, today we’re going to explore a curious question that we get a lot: are all calories created equal?

By definition, a calorie is just a unit of energy. Create a calorie deficit - and you will lose weight, even if your diet is comprised solely of highly processed, packaged foods. Go over your energy expenditure - and you will gain weight even if everything on your plate is very nutritious. In this regard, thermodynamics dictate that a calorie is a calorie, regardless of its source.

However, you’ve probably noticed that different foods can make you feel differently. If you compare a busy day where you just snack on fast food here and there to a planned day of balanced meals made from whole foods, you will probably feel a difference. This holds true even if the calories between these days match up! 

Turns out that different combinations of nutrients trigger different biochemical pathways, influencing fullness, appetite, and other factors. How exactly? Let’s explore!

Fullness and satiety

Different foods affect fullness differently - even if they contain the exact same calories!

Take a look at the options below and try to guess which one is most likely to leave you satisfied (each option contains approximately 240 calories):


Science says that will find yourself much fuller after eating boiled potatoes compared to their caloric equivalent in croissants or white bread, which can be contributed to higher fibre content and overall volume.

Examples like this are plentiful! Specifically, filling foods tend to be:

  • High in volume - e.g. contain lots of water or air (e.g. light soups, popcorn)
  • High in fibre - as it slows down digestion and creates bulk (e.g. vegetables, legumes)
  • And/or high in protein, which promotes feelings of fullness and satiety via several hormonal pathways (e.g. eggs, greek yoghurt)

Whole, unprocessed foods are more likely to possess combinations of these factors - hence they are generally more filling. This is a great factor to keep in mind if your goal is fat loss, and you’re looking to get more “bang” for your limited calories without feeling deprived.

So, when it comes to creating fullness, it certainly matters where the energy comes from. 

Protein and appetite

In addition to being relatively filling, research shows that protein-rich foods may also suppress appetite for longer following your meal. This means that pushing more of your calories towards protein can help you eat fewer calories or vise versa. 

It is recommended that active individuals consume around 1.6-2.2 grams of protein per kg of body weight per day to preserve or build muscle mass. Manipulating protein intake within that range can be a great way to achieve your goals more comfortably!

Looking to add extra protein to your day? Try one of the many delicious recipes from the BBR app, such as these delicious Apple Pie Protein Pancakes:

Carbohydrates and blood sugar levels

Various types of carbohydrate-rich foods can be processed in the body differently, too!

Every time we eat carbs, blood sugar (glucose) and insulin levels rise - however, by how much and how quickly, depends on the kind of food you eat.

A measure of how much a food boosts blood sugar is called the glycemic index (GI). High GI foods induce quick insulin and blood sugar spikes followed by a quick drop, whereas eating lower GI foods spreads this out:

Low GI foods include most veggies and fruit, legumes, beans, nuts, low-fat dairy and minimally processed foods. These foods are more likely to keep your blood sugar levels steady for longer, meaning you will probably find yourself satisfied for longer.

In contrast, foods such as white bread, highly processed cereals and white rice have a much higher GI. After consuming a snack containing exclusively high GI carbs, you are likely to get munchy again very soon!

This is not to say that you should completely avoid foods with a high GI! True, if you eat the same caloric value in isolation (e.g. with no other foods), you'll definitely feel hungry sooner after eating the high GI food compared to the low GI option. However, for most meals, you are likely to combine carbs with other macros, which further affects how the foods are processed. 

In saying that, if you’re reaching for a carbohydrate-based snack, a piece of wholegrain toast is likely to fill you up more than, say, a handful of jelly beans. In contrast, in some situations (e.g. for quick energy before a workout), consuming a small serve of high GI carbs may be just what you need as a pick-me-up if it’s been a while since your last meal. 

So, just because something has a higher glycemic index, doesn’t mean it’s “bad” or “inferior”! As with everything, it’s all about the context.

Thermic effect of food

We’ve already briefly touched on the thermic effect of food in the previous blog, however it’s such a great example that we’d like to discuss it in more detail!

Researchers have been investigating TEF as a potentially modifiable component of energy expenditure, and it’s been found that strategies to increase TEF include:

  • Consuming larger meals
  • Increasing protein and carbohydrates in your macronutrient split
  • Incorporating more plant-based foods
  • Adding spices to dishes

It is worth noting that these TEF-increasing strategies do not exactly have dramatic metabolic effects. However, they still show that altering the contents of your plate whilst keeping overall calories the same can influence energy expenditure!


Although by definition all calories are created “equal” in terms of how much energy they provide, the body treats them differently depending where they come from! 

Being calorie-conscious is important for reaching your goal, but so is ensuring your diet includes a variety of nutritious foods delivering all required macro- and micronutrients. 

This blog concludes the Energy Balance series - and we hope you have enjoyed reading these and have learned something new! See you again soon, gorgeous lady!