ood provides the energy we need for making our body function and renew itself even while we’re asleep or watching a video. The energy is measured in kilojoules, a change from the non-metric calories. Because of their faster metabolism, some people burn energy (or calories, or kilojoules) faster than others. Teenagers, children, pregnant women and naturally larger people generally need more kilojoules.

Calories and kilojoules are calculated from the composition of different foods. For example, a gram of fats gives 37 kilojoules, a gram of alcohol 29 kilojoules and a gram of carbohydrate provides 16 kilojoules.

But the trouble with counting calories or kilojoules is that it ignores vitamins and minerals and makes no distinction between whether or not you’ve had any greens in the last calendar year. It encourages an obsession with tiny bits of food and discourages listening to your body to find out what it is telling you it needs. There are many other considerations in eating apart from simple kilojoule consumption. How big are you naturally? How much exercise do you do? Do you feel like an icy pole?