Teaching you the essentials of fitness and weight loss

Understanding food labels and calories

Many of my clients work really hard during their personal training sessions and those who have been with me a while have really started to enjoy exercising. However, many of them struggle when it comes to getting their diet right. Most of them know that in order to lose weight, they need to eat less calories than they are burning but what they may not know is that not all calories are created equal. In this blog post, I de-mystify food labels and those calories!


Different foods provide us with different amounts of energy when they are broken down in the body. A gram of carbohydrate releases 4kcals, a gram of protein also releases 4kcals, a gram of fat releases 9kcals and a gram of alcohol releases 7kcals. So the energy in food depends on how much of each macronutrient (carbs, protein and fat) is in the food. For example, one slice of wholemeal bread provides roughly the same amount of energy as 7g of butter. However, approximately 75% of the energy in bread comes from carbs and 99% of the energy in butter comes from fat. So fat is by far the most concentrated form of energy, although it is not necessarily the best source of energy to power you through your exercise sessions.


So how can you make sense of the food labels and work out how many calories are coming from fat, protein and carbohydrates? It’s actually really simple! Let’s compare beef mince and cod. We’ll say that 100g of beef mince contains 332kcals, 30g fat, 0g carbohydrate and 14g protein. That means that 56kcals comes from protein (14g x 4kcals), no calories come from carbohydrate and 270kcals come from fat (30g x 9kcals). Thats a lot of fat! 100g of cod on the other hand contains 82kcals, 0.7g fat, 0g carbs and 18g protein.┬áThat means that 72kcals comes from protein (18g x 4kcals), no calories come from carbohydrate and only 6kcals come from fat (0.7g x 9kcals).


So how much of each macronutrient should you be eating to lose weight? Well, research actually suggests that the macronutrients in your diet are less important than the quality of the foods you are eating. Most people could eat 10 chocolate eclairs as their daily diet and still lose weight because they’d be burning more calories than they were consuming. They would however, be consuming around 873kcals from fat, 480kcal from carbohydrates (mostly sugar) and 96kcals from protein. Which sounds like a recipe for both diabetes and a heart attack! You’d probably also be hungry if you tried this due to the low amount of protein and you certainly wouldn’t be getting the correct nutrients! A healthy, balanced diet on the other hand could give you the same amount of calories, which would mean that you were still losing weight, but also fuelling your body correctly, helping to avoid any future health complications.


In summary? Personally, if I were looking to lose weight, I would keep an eye on my sugar intake (divide the amount of sugar in a food by the total amount of carbohydrates and then multiply by 100 to get the percentage of “naughty carbs”) – the lower this percentage, the better the quality of the carbohydrate. I would also look to limit my fat intake. Plus, the golden rule of weight loss – make sure I burn more calories than I am consuming.