Calories and kilocalories
The term calorie is a commonly used shorthand for "kilocalorie". On food packets, you'll find this written as kcal. Kilojoules (kJ) are the metric measurement of calories, and you'll see both kJ and kcal on nutrition labels – 4.2kJ is equivalent to approximately 1kcal.
Energy throughout the day
Within a healthy, balanced diet, women need on average 8,400kJ a day (2,000kcal), while men need on average 10,500kJ a day (2,500kcal).
A rough guide to how your energy requirement can be spread throughout the day is as follows:
- breakfast: 20% (a fifth of your energy intake)
- lunch: 30% (about a third of your energy intake)
- evening meal: 30% (about a third of your energy intake)
- drinks and snacks: 20% (a fifth of your energy intake)
As you can see, any drinks or snacks you have count towards your daily energy total. If you eat more for your breakfast, lunch or evening meal, you may need to drop a snack later in the day to stay on track.
Comparing energy values: a visual guide
This guide shows energy values for 10 different foods. This will help you visualise what 100kcal (420kJ) looks like and manage the number of calories you consume.
This amount, 100kcal, represents just 5% of a woman's daily reference intake (4% for men), but this quickly adds up when adding ingredients during cooking or when we reach for a snack.
High-fat foods have more energy because fat contains more than double the calories per gram compared with protein and carbohydrates. Foods containing mainly water, such as vegetables, have even less.
This guide shows how quickly calories can add up in certain foods. Some of the photos have household objects, such as a pack of cards, to help illustrate the size.
Calories in oil, mayonnaise and butter
All types of fat are high in energy. A gram of fat provides 9kcal, compared with 4kcal for carbohydrate and protein.
Oil and butter are almost pure fat, which is why 420kJ/100kcal is:
- just a little over 1 tablespoon of olive oil
- 1 level tablespoon of mayonnaise
- just under 1 tablespoon of butter (a thick spread of butter on your bread)
Calories in cheese
Most cheese is high in fat, so 420kJ/100kcal is just under a 30g matchbox-sized piece of cheddar cheese.
Calories in sugar
Calories in sugar can add up if not used sparingly, especially for people who drink tea or coffee with sugar throughout the day. Four heaped teaspoons of sugar is 420kJ/100kcal.
Find out how sugar affects your health.
Calories in biscuits
A lot of biscuits are high in fat and sugar and low in nutrients, so 2 ginger nut biscuits add up to 420kJ/100kcal. Other biscuits may be higher in energy, such as those covered in or filled with chocolate.
Calories in crisps
Crisps, which are often high in fat and salt, can quickly add up to 420kJ/100kcal. For example, the 190g tube of crisps featured in this picture contains nearly 1,000 calories, so just 10% of a tube (9 crisps) equals 420kJ/100kcal.
Calories in meat and fish
The kind of meat you eat could make a big difference to the amount of energy you consume. For example, this is what 100kcal of steak looks like:
On the other hand, turkey and fish are both low in fat and lower in energy, so 420kJ/100kcal is about 3 slices of turkey or a few spoonfuls of plain large prawns.
Calories in dried fruit
For 420kJ/100kcal, you'll get just over a 30g portion of raisins. A 30g serving of dried fruit counts as one of your 5 A Day, whereas an 80g serving of fresh fruit, such as grapes or cherries, counts as one of your 5 A Day.
Calories in fresh fruit
For 420kJ/100kcal, you can tuck into any of the following:
a large apple
These all count towards your 5 A Day, which should include a variety of fruit and vegetables.
Calories in vegetables
Vegetables are generally low in calories, while bringing the added benefits of fibre, vitamins and minerals.
To illustrate this, 420kJ/100kcal is equal to:
Check the nutrition label
Remember, this page is only intended as an illustration, as all foods vary in energy content and this can depend on how they're made or prepared, and how much you eat.
Most prepackaged foods have a nutrition label on the side or back of the packaging, which will give a guide to the energy content.
Get advice on counting calories in non-packaged foods, such as loose fruit and vegetables or fresh bread.
Read about understanding calories for more information about energy values in food.