Question

Adult consumption and its unit and energy in human nutrition and its unit

Answer 1

Hey mate
In order for humans to carry out ordinary life functions and processes they must obtain energy. This energy comes from consuming food and is measured in calories in the United States and joules everywhere else. A gram calorie is the amount of energy need to increase the temperature one degree for one gram of water. However in terms of nutrition and diet a calorie is used to represent a kilocalorie. Thus if an apple has 70 calories, its true energy content is 70 kilocalories. Since 1925 the unit joule has replaced the calorie as the unit of energy; 1 calorie is equivalent to 4.184 Joules. Energy from food can be measured using a calorimeter, which measures the heat released when food is oxidized.
According to one of the above sources, in 1975 humans consumed 2.51 × 1020 Joules of energy through fossil fuels. Compared to the 1.34 × 1019 Joules of energy consumed through food, humans ironically use roughly nineteen times more energy than they eat. If we limit the amount of energy we consume via fossil fuels to the amount of energy we consume through food, would we be able to scratch the energy issue off our chalkboard?