Please find your mark scheme and model answer below:
Malnutrition
Edexcel, June 1999

Obesity and smoking are two risk factors in coronary heart disease. An increase in either of these gives a higher than average mortality risk.

A person with a body mass index (BMI) of 30 or above is described as obese.

The graph below shows the relationship between the BMI and the mortality risk of groups of smokers and non-smokers.




    1. Question:

    1. Describe how the BMI of an individual is obtained.

      (2 marks)
      Answer:

      mass / weight in kg and height in m (1)

      mass / weight divided by height squared(1)


      Question:

    2. Name one tissue that increases in masses an individual becomes obese.

      (1 mark)
      Answer:

      adipose/fat (1)


    2. Question:

    1. Using the information in the graph, calculate the increase in mortality risk for non-smokers with a BMI of 31 if they were to start smoking. Show your working.

      (2 marks)
      Answer:

      2.2 - 1.08 [ALLOW 1.075 to 1.1] (1)

      = 1.12 arbitrary units/ units [ALLOW 1.1 to 1.125] /OR 100% to 104.7% rise (1)


      Question:

    2. Compare the effect of smoking and increasing BMI on the mortality risks for individuals whose BMI is greater than 26.

      (3 marks)
      Answer:

      smokers risk always at least 2× that for non-smokers /eq (1)

      increase in risk as BMI increases (1)

      steep increase in risk for smokers at BMI 30 / when obese /OR steep increase in risk for non-smokers at BMI 34 (1)

      non-smokers with BMI 36 have higher risk than smokers at 26 (1)

      between 32 – 34 little change / no change for smokers /OR increases more for non-smokers (1)


      Question:

    3. Suggest one reason why smoking is a risk factor in coronary heart disease.

      (1 mark)
      Answer:

      raises blood pressure / raised pulse rate/eq OR ref. to carbon monoxide / CO combining with Hb / reducing oxygen carriage by Hb OR decreases antioxidants (in blood) OR increases blood cholesterol OR constriction of coronary arteries OR rise in ratio of LDLP:HDLP OR Increased number of platelets OR platelets more sticky OR increase risk of plaque formation in coronary arteries (1)


    Question:

  3. Explain how people who are obese can reduce their body mass index.

    (2 marks)
    Answer:

    ref. to need to get energy expenditure higher than energy intake /eq (1)

    reduce carbohydrate /fat intake / ref. to low fat / low calorie diet / increase exercise / activity (1)


(Total 11 marks)