What is a calorie?

The amount of energy in a food or drink is measured by calories. When we take in more calories than we need, our bodies store it as a secondary source of energy and we put on weight. Understanding calories can help us avoid that. 

 Current NHS guidelines recommend 2500 calories for men and 2000 for women for weight maintenance.  

To maintain a healthy weight, our energy input (the food we eat) needs to match our energy output (the energy we use living day to day life, eating, working, exercising).  

To lose weight, we need to be in a caloric deficit – our input of calories needs to be less than our output. This means our bodies have to use their secondary sources of energy, body fat.  

Not all calories are equal. It’s helpful to understand their energy value per gram.  

  • Fats 9 calories  
  • Carbohydrates 4 calories  
  • Protein 4 calories  
  • Alcohol 7 calories  

On top of this, some calories are ‘empty’, in that they provide no other benefits like vitamins and minerals, whereas others are packed with goodness. Quality calories are found in fruit, veg, whole grains, lean proteins and healthy unsaturated fats. 

Lower energy dense foods provide fewer calories per gram. This means we can have a satisfying meal with a low calorie content. Lower density foods include those with a higher water content, foods that absorb water whilst being cooked or foods that have a naturally high water content. Examples include: fruit & vegetables, soups & stews. Medium density foods should be included in our diet everyday as they work towards a healthy balanced diet. This includes fish, lean meats and low fat cheeses. 

Higher energy dense foods tend to include foods that are high in fat and low in water content. Examples include crisps, butter, oils, biscuits, and confectionery. We can still have foods from this category, only aim for infrequent, smaller portions. 

Hidden calories from fats and sugars can add up. Here’s a few common foods that can contain copious calories: dried fruit, condiments like tomato ketchup, dressings and toppings, milky or syrupy coffees and teas.  

Make sure your healthy, balanced diet includes 5-a-day, whole grain carbohydrates, lean meat/fish, low fat dairy and the occasional treat. That way, you shouldn’t find yourself eating excess calories. 


Get the scoop with healthy lifestyle advice, tips and guides from our experts.

The unknowns of vaping

Using a vape can help you when you’re quitting smoking, and vaping is thought to be up to 95% healthier than smoking cigarettes. But there’s so much we don’t know about vaping. Here’s what that means. 

Read More »