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ActivHealth Guide To Calories

What Are Calories?

Calories or kilocalories (k/cals) indicate the amount of energy in an item of food or drink.

This is the energy that once digested will provide us with the fuel we need to firstly maintain normal bodily functions such as breathing, digestion and regeneration and secondly, to fuel the exercise or activity we choose to do beyond that basal requirement. Depending on the source of the calorie it may also provide us with an array of critical nutrients such as dietary fiber, amino acids, antioxidants and dietary vitamins and minerals.

We obtain calories from three primary sources within our diets. What we term commonly as macronutrients. Each of which contains a given amount of energy per gram.

Are All Calories Created Equal?

When it comes to the laws of thermodynamics the answer is yes.

A unit of energy is a unit of energy so when it comes to controlling and regulating someone’s caloric intake for compositional purposes, the numbers count. This is when we can talk about calories in (what we consume) vs calories out (what we use) being the major determining factor in someone’s compositional change.

At this stage it’s good to understand the thermic effect of food (TEF). The thermic effect of food refers to the energy required for digestion, absorption, and disposal of a given nutrient following ingestion. In essence, we need calories to break down the energy in food.

Carbohydrates: 5 to 15% of the energy consumed

Protein: 20 to 35%

Fats: at most 5 to 15%

Energy & nutrient Density

Energy density is the amount of energy, as represented by the number of calories, in a specific weight of food.

Foods that are energy-dense have a large number of calories per serving and tend to include foods that have a high sugar content, are high in fat and have a low water content.

These should lay a smaller part in your diet.

Nutrient density is the amount of dietary fibre, complex carbohydrates, amino acids, antioxidants and dietary vitamins and minerals. Which are represented by the number of calories in that weight of food.

Packing a diet with a higher proportion of nutrient dense food with a lower ratio of energy ultimately gives you a diet that can satisfy both hunger and taste whilst sustaining an intake of calories relative to your goals.

What you need to consider

When it comes to the food you regularly consume, you need to consider both the taste and satiety.


The sense of taste is one of the most important human senses.

Your experience of flavour of food or drink, arises from the integration of multiple sensory cues, including odour, taste, temperature, and appearance.

The food and drink we consume need to be perceived as appealing and not just as satiating; taste quality is therefore critical in any type of long term dietary compliance.


Satiety is the term used to explain the feeling of fullness and suppression of appetite that happens after eating a specific food or combination of food. Food with a high level of satiety will help prevent overconsumption because, well, it makes you feel full.

Filling foods, or foods with a high level of satiety tend to have one or more of the following characteristics:

HIGH IN PROTEIN: Research shows us that of all the macronutrients, protein is the most satiating.

Consumption of protein also has a positive impact on the levels of several hormones that impact satiety.

Understanding energy expenditure

In the balancing act of managing our energy intake vs energy expenditure it’s important you understand what contributes to your output.



Throughout the course of a day you can bracket your expenditure into two different types.

Resting energy expenditure and BMR

This accounts for more than 60% of your total energy expenditure. Even when resting, your body utilises energy (calories) by performing basic functions to sustain life, such as breathing, circulation, the processing of nutrients, and cell regeneration. This is known as your basal metabolic rate or BMR.

Non-resting energy expenditure (this is made up of three components)

  1. NEAT or non-exercise activity thermogenesis.

NEAT is the energy expenditure we have walking, standing, climbing stairs, fidgeting, and maintaining and changing posture. Anything outside of formally planned or structured exercise falls under this category.

  1. EAT or Exercise Activity Thermogenesis

EAT is defined as planned, structured, and repetitive physical activity with the objective of improving health. Doing sport or going to the gym falls under this category. NEAT accounts for much more energy expenditure than EAT therefore habitual daily activity and movement can contribute hugely to improving energy balance.

  1. TEF or Thermic effect of Food

As previously mentioned, this relates to the amount of energy required to digest, absorb and store food.

Understanding Food Labels


This gives you an insight into the foods energy density by offering the weight of a single serving (g) alongside the number of servings in the container. The serving someone may choose to use may not be reflective of the proposed serving size.

Per serving, per 100g and % RI

All nutrition information is provided per 100 grams of the product and often, it will also be presented per portion of the food product too. It is generally best to calculate the macronutrient percentages using the per 100 grams values as the suggested portion may not be reflective of the serving size you choose, and you may end up consuming more than you had planned or realised.


The amount of energy in a food or drink is measured in calories. On food labels, the calorie content is given in kcals and kJ, which are short for kilocalories
and kilojoules. Kilojoules are the metric measurement of calories.

Other Useful Information You Might Need


Fibre helps to keep our digestive system healthy and helps to prevent constipation.

Your daily target is 30g of fibre per day. Remember that nutrient dense and filling foods have loads of fibre typically.


Starchy foods are a good source of energy and the main source of a range of nutrients in our diet. As well as starch, they contain fiber, calcium, iron, and B vitamins. Wholegrain varieties of starchy foods and potatoes – particularly when eaten with their skins on – are good sources of fiber.


Mono/poly unsaturated fats are deemed as ‘healthier’ fats and should be incorporated into your daily eating patterns.

Monounsaturated Fat

Sources of monounsaturated fat include:

  • Avocado
  • Almonds, cashews and peanuts
  • Cooking oils made from plants or seeds like canola

olive, peanut, soybean, rice bran, sesame and sunflower oils.

Polyunsaturated fat

Sources of polyunsaturated fat
(omega-3 and omega-6)

  • Fish
  • Tahini (sesame seed spread)
  • Linseed (flaxseed) and chia seeds
  • Soybean, sunflower, safflower, and canola oil, and margarine spreads made from these oils
  • Pine nuts, walnuts, and Brazil nuts


Calculating your energy requirements, especially when you are trying to lose or maintain weight is important. We will more than happily assist you with ascertaining your daily energy requirements.


For many people food will be acquired in different ways. Statistics tell us that if you were born after 1976 there is a high likelihood you don’t cook much. Presenting you with an array of recipes and combinations of food to create yourself could be only part of a solution.

Not only do you perhaps lack the skills to create it but also the skills to make what you prepare tasty and therefore part of a sustainable plan.

If you do possess those skills, great, we will happily provide you with ideas and recipes to make your diet more satiating, nutritionally dense, and in alignment with your goals.

But If you don’t then we will also assist you with the acquisition of food.

Taking into consideration where you eat, when you eat, who you eat with, the time you have to eat, your budget and where you get your food from.

We will help you with the planning and logistics of whichever approach or approaches you choose to adopt.