It’s CICO Time: Calories In

Aside from being one of the greatest puns of our time, CICO (Calories In, Calories Out) is what determines whether we lose, gain or maintain weight. This article will discuss the factors that influence energy intake. And yes, it’s CICO time is the greatest pun I have ever thought of.

There are more influences on energy intake than there are disappointing men on Tinder. Similarly, some influences are more complex and impactful than others, and this the response to each influence is largely individual. For the sake of simplifying these influences, I have grouped these factors into three main categories:

  1. The Food Itself
  2. The Internal Environment
  3. The External Environment

#1: The Food Itself

The most obvious factor influencing our energy intake is food itself. Eat more food, you have a higher energy intake. Eat less food, you have a lower energy intake. Thus concludes our intensive 8-week course on energy balance.

Macros, Bro.

Not all calories are created equal, and some can shift the energy balance in either direction more than other. Every food we eat is composed of varying amounts of macronutrients. There are three* types of macronutrients: carbohydrates (CHO), protein and fat.

Each macronutrient has a different energy ratio:

  • Each gram of CHO contains 4 kcal.
  • Each gram of protein contains 4 kcal.
  • Each gram of fat contains 9 kcal.

*The fourth macronutrient is alcohol, and contains 7 kcal per gram. Alcohol will be covered in a separate article.

You can see that if you were to eat 100g of protein, this would equate to 400 calories. Whereas if you ate 100g of fat, this would amount to 900 calories. This is not to say that protein is “better” because it contains less calories, and you need fat to survive. It is simply to point out that fat-based foods are more energy dense than others.

Few of the foods we eat are purely one macronutrient. Even things like whey protein will contain at least a gram or two of CHO. It’s why you here people banging on about a “balanced” diet, to ensure you get the correct balance of macronutrients that suit your goals.

Food: Structure & Digestion

As above, we use macronutrients in food to give us energy that we use to keep ourselves alive. Not all macronutrients affect us equally, even within macronutrient categories. For example: carbohydrates are generally divided into two camps: sugar/simple carbohydrates and complex carbohydrates. Sugars as the name suggest have a simpler structure and are easier broken down and digested than complex carbohydrates. They release their energy quicker. If you ever played team sports as a kid, it’s why you were given oranges/Jaffa cakes at half time instead of a plate of spuds. Both spuds and Jaffa cakes are CHO sources yes, but we get energy from them differently.

Similarly, we alter the composition of food by cooking it or processing it and thus we affect the energy we can get out of it. You wouldn’t eat 200g of flour straight from the bag (I hope), but you’d have no problem eating a batch of cupcakes. Typically, we absorb less energy from “wholefoods” (read: unprocessed) than processed foods. We also use less energy to digest processed foods1.

Take home points: we can change how much energy we can get from foods by cooking them. Our body needs to work harder to access the energy from wholefoods. Therefore, our body will use more energy to digest wholefoods.

#2: The Internal Environment


Much like how we are all unique and special snowflakes, we each digest and process foods differently. Certain people will have issues with certain food that others may not. Some people are lactose intolerant, some are coeliac and some have other allergies. People with allergies to certain foods will not get energy from that food in the same way you or I would. For example, if you have a peanut allergy, you won’t be getting the 200 calories from a serving of peanuts. You’ll be getting a serving of epipen with a side of anaphylaxis.

What works for me might not work for you. This highlights the importance of tailoring your nutrition to your individual needs.


There are a number of “hunger” hormones in the body that help regulate our appetite and satiety. Ghrelin is responsible for increasing our sense of hunger. Leptin can increase or decrease our energy expenditure in response to signals from our adipose (fat) tissue. These two hormones are the king and queen of appetite regulation, but other hormones such as insulin also play a role.


To some extent, your education can play a role in your energy intake. An awareness of the energy content of your food and your habits can affect your caloric intake. If you know you need to eat 2,000 calories to lose weight and roughly what that looks like, you can act accordingly. Conversely, if you have no idea what you’re eating and how it affects you, that can also affect your caloric intake.

It always brings us back to the infamous Dr. Maya Angelou quote: “When you know better, you do better.”


Mindset is perhaps one of the biggest influences on our energy intake, but one we rarely consider. We can get lost in the world of calories and eating X for certain goals and ultimately forget about what is behind all of our food choices: us. Emotions, stress, trauma, goals and headspace. All massive influences on our energy intake. Some people comfort-eat, some people don’t eat at all and some people are vary between the two at different times. We can use food as a crutch, or we can use it as a stick to beat ourselves with when we feel down. Sometimes, focusing on our mental health is more important than being entirely focused on the physical.

#3: The External Environment

The external world also plays a massive role in our energy intake. Different cultural practices and rituals shape our lives. Our daily routines largely shape our energy intake. You may have a habit of skipping breakfast. You may live in a house where you get a takeaway every Saturday night, non-negotiable. You may eat a big dinner after a heavy workout. All of these rituals and practices can affect your energy intake, independent of your goals.

Accessibility of food is one that most of us are fortunate not to consider, but not everyone is so lucky. Some of us cannot afford nor have certain foods available to us.

In our homes, our workplaces and our society, food can be a massive part of our environment. We are products of our environment to varying degrees. If you surround your home environment with food that is supportive of your goals, you are more likely to achieve them. If your goal is weight-loss and your office have a canteen that only serves fried foods, that can affect your energy intake and your goals. Your environment can be limiting, but it’s not everything.


This is intended to give you an overview of the main governing factors influencing our caloric intake. From reading this article, you have gained an insight into just how many things influence what we eat. This will hopefully lead you into questioning why you eat what you eat.

I haven’t covered everything, nor do I intend to. What we eat is so much deeper than just “calories in”. It is a large component of who we are, shaped by an absolute HEAP of factors ranging far and wide.

The next article in this series will discuss the factors influencing our energy expenditure, and give me an opportunity to use the “It’s CICO time” pun again.


  1. Barr, S.B., Wright, J.C. (2010) ‘Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure’ Food & Nutrition Research. Available at:

Published by Michelle Carroll

I am an online coach (MSc Sports & Exercise Nutrition, EQF Level 4 Personal Trainer, PN Level 1) and radiographer (BSc). I believe in empowering others to make better choices for their health through education. I think that the fitness industry has created a disconnect between best practices and “evidence-based” practices. I hope by chronicling my experience as a healthcare professional and my education as a fitness professional I can assist others on the path to bettering themselves.

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