Have a go at this question on energy requirements. Write out your answers on paper or a printout of this page and fill it out-
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    Question:
  1. State three components of a balanced diet which provide energy.

    [3]
  2. Four investigations of the energy intake of 14 and 15 year old boys and girls have been carried out in the UK since the 1930s. These studies show that the average intake of energy has decreased, while the average body masses of both boys and girls have remained the same. The results of these investigations are shown in the Table

    investigation average energy intake / kJ per day
    boys girls
    1930s 12 873 11 088
    1960s 11 739 9 534
    1970s 10 962 8 484
    1980s 10 478 8 316
    1. Question:
    2. Calculate the percentage decrease in energy intake for boys between the 1930s and the 1980s. Show your working.

      [3]
    3. Suggest two reasons for the fact that the intake of energy has decreased between the 1930s and the 1980s while the average body mass has remained constant.