{"id":9113,"date":"2021-01-06T15:12:12","date_gmt":"2021-01-06T07:12:12","guid":{"rendered":"https:\/\/paulstokes.com.au\/?p=9113"},"modified":"2021-02-26T10:12:59","modified_gmt":"2021-02-26T02:12:59","slug":"what-is-a-calorie-and-a-kilojoule-how-to-measure-your-energy-budget","status":"publish","type":"post","link":"https:\/\/paulstokes.com.au\/what-is-a-calorie-and-a-kilojoule-how-to-measure-your-energy-budget\/","title":{"rendered":"What is a Calorie and a Kilojoule? How to Measure your Energy Budget"},"content":{"rendered":"

We hear about calories all the time. How many calories are in this cookie? Or how many do we burn in this exercise class, or with 20 minutes on the cross-trainer? But what actually is a calorie anyway? And how many of them do we need each day?<\/p>\r\n

Essentially, calories are a way for us to keep track of our daily energy budget.<\/p>\r\n

When we’re in a healthy balance, we put in (i.e. eat) about the same amount of energy as we use. Over time, if we regularly put more energy into our bodies than we use, we’ll gain weight. Our body will gradually store the excess energy in our fat cells.<\/p>\r\n

On the other hand, if we continually use up more energy than we take in, we lose weight.<\/p>\r\n

It’s useful then for us to be able to measure the energy we are taking in and using. This is where the calorie (and kilojoules) comes in.<\/p>\r\n

Essentially, the calorie is just the unit we use to measure energy<\/h3>\r\n

You’ll see calories listed on nutrition labels as kcal.<\/p>\r\n

By definition, 1 calorie is the amount of energy it takes to raise the temperature of 1 kg of water by 1 degree Celsius.<\/p>\r\n

Kilojoules work similarly, they just use a different method to quantify energy. Some countries show kJ on nutrition labels rather than kcal.<\/p>\r\n

Technically, the joule (or kilojoule) is the Standard International Unit for measuring energy. One Joule is defined as the work required to exert a force of 1 Newton over a distance of 1 metre.<\/p>\r\n

Okay, that’s enough of the physics, but you might like to know that calories and kilojoules are linked. Their scales are proportional so you can convert one to the other and vice versa. To convert calories into kilojoules, multiply by 4.184. On the flip side, to convert kJ into kcal, divide by 4.184.<\/p>\r\n

Everything we eat (and drink) has a calorie count<\/h2>\r\n

Basically, it’s a measure of how much energy is stored within the food<\/p>\r\n

Commercial Carrot Cake (100g slice) 1675kJ 400kcal<\/p>\r\n

1 Granny Smith Apple 309kJ 74kcal<\/p>\r\n

Chicken Breast (100g) 438kJ 105kcal<\/p>\r\n

1 Egg 235kJ 56kcal<\/p>\r\n

375ml Can Coca Cola 803KJ 192 kcal<\/p>\r\n

Figures supplied by Food Standards Australia New Zealand<\/a><\/p>\r\n

During digestion, our body releases energy from food and stores it in other molecules. When we need to use some, these molecules get broken down to provide energy.<\/p>\r\n

Typically, our bodies use this energy in 3 main ways:<\/p>\r\n