Kilojoules are more fattening than kilocalories

False. Both kilojoules and kilocalories are units of energy. When we eat food, we convert it into energy which j used to perform bodily functions such as breathing, circulating blood, moving muscles, maintaining body temperature, etc.

The kilojoule is the unit now most widely used for expressing food energy. It is based on an international system of units designed to minimise differences in terminology between countries. Energy used to be measured in kilocalories (sometimes this was simply called calories). One kilocalorie is equivalent to 4.186 kilojoules. As an approximation, to find the number of kilojoules in food, multiply the number of kilocalories by four.

The energy (kilojoules) provided by a food depends on the amount of protein, carbohydrate, fat, alcohol, water, and dietary fibre in it. The energy contributed by these food components is shown in the following table:

FOOD COMPONENT KILOJOULES
PER GRAM
KILOCALORIES
PER GRAM
Protein
Carbohydrate
Fat
Alcohol
Water
Dietary fibre (if fermented in the large intestine)
17
16
37
29
0
13
4
4
9
7
0
3