Food Labels: Counting Calories And Hidden Fat

Avatar for Hadyn Luke Hadyn Luke posted this on Monday 24th of April 2023 Hadyn Luke 24/04/2023


Food Labels: Counting Calories And Hidden Fat

Food Labels: Counting calories and hidden fat

Calculating calorie needs can be a simple and/or complex thing. Whether you use the Harris-Benedict equation, a more basic formula, or maybe just a trial-and-error approach to your calorie needs, it is important to understand the content of those calories.

A reasonably active individual will need to consume around 2,000 calories a day. But whether you are looking at your own dietary needs, or you are a personal trainer advising a client, it’s important to understand where these calories come from in order to ensure a healthy, balanced diet.


Most foodstuffs now have a detailed breakdown on the label – by law, every food package will have the total calories per 100g and the number of macronutrients (protein, fat and carbs) per 100g.  But there are two key points that will help you make the best use of this information:

  1. For a balanced diet, your daily intake of calories should be made up of approximately 10-20% protein, 20-30% fat and 50-60% carbohydrates;
  2. 1 gram of protein and 1 gram of carbohydrate each contain 4 calories, but a gram of fat contains 9 calories.

If an individual has a target calorie intake of 2,000kcal per day, they could divide these calories into four equal meals of 500 calories a day (you don’t have to do this though – this is just easier for this example!). If the client is eating 20% protein, 30% fat and 50% carbohydrates, then each meal should look like this:

  • Protein – 500kcal X 0.2 (20%) = 100kcal of protein per meal / 4 kcal per gram = 25g of protein per meal.
  • Fat – 500kcal X 0.3 (30%) = 150kcal of fat per meal / 9kcal per gram = 17g of fat (30%)
  • Carbohydrates – 500kcal  X 0.5 (50%) = 250kcal per meal / 4 kcal per gram = 62.5g of carbohydrate per meal

Therefore the ideal meal in this scenario would consist of 25g of protein, 17g of fat and 62.5g of carbohydrates to be eaten four times a day at regular intervals.

However, when looking at food packaging, it can be confusing and people often compare the macronutrient content to weight rather than the calorie content. It is important to work out the percentage fat, carbohydrates and protein in a product as a percentage of calories rather than weight. 

Why is this important?

Take a standard 25g bag of ready-salted crisps at 134 calories with 8.5g fat.

If you calculate the fat % based on weight, the fat % of the food would be 34% (8.5g / 25g = 34%).

However, if you calculate the fat % based on calories per 100g.

1g fat = 9 calories

8.5g x 9 = 76.5 calories

76.5 / 134 (calories per pack) = 57%

So the percentage fat consumed is higher than you might think looking at the percentage in weight. It’s therefore not enough to count calories, you need to understand where these calories are coming from.


This guidance isn’t saying that you can’t eat ‘high fatty’ foods/snacks/meals. Your intake should be balanced with your lifestyle choices and if some snacks or meals are high in fat that is fine. You may even manipulate your macronutrient splits according to your training needs e.g. high carb, moderate protein, low fat,  pre and post-workout, but moderate fat, moderate protein and low carbs at other meals.

What you will need to consider though, is:

  • If a snack or a meal has 57% fat, rather than the recommended 30%, other snacks or meals with a much lower fat content than 30% will have to be consumed to balance it out and this can be difficult to achieve.
  • If the intake of one macronutrient is high, you are less likely to hit other macronutrient goals within a given calorie limit.
  • Having a balanced diet that consumes protein, complex carbs, and fat, will generally keep you fuller for longer. Whereas, eating a meal/ snack that is particularly high in one macronutrient will digest quicker and you will be hungrier quicker, resulting in eating more calories.

For more information on personal trainer courses, visit Level 3 Diploma in Personal Training

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