Briefly describe what is meant by “obesity”.

Suggest why heart disease is considered a “disease of affluence”.

With the aid of a diagram or diagrams, explain the spatial process of a disease spreading through “diffusion by relocation”.

Examine the factors which have led to more food becoming available in some areas in recent years.

BMI (Body Mass Index) over a certain number / a form of malnutrition [1 mark], usually resulting from energy (calorie) intake exceeding the amount required [1 mark].

Rates of heart disease are lower in poorer countries than in richer/wealthier/more developed countries [1 mark]. Award [1 mark] for each factor that is explained. These may include dietary factors e.g. a high fat intake (especially high saturated fat), high levels of “bad” cholesterol, and obesity. Lifestyle factors include insufficient physical exercise, stress levels, preference for sedentary occupations, reliance on powered forms of movement such as motor vehicles rather than walking, and decision to spend discretionary income on particular kinds of food.

For [4 marks] both dietary factors and lifestyle factors should be addressed. A wide range of suggested factors may compensate for depth of explanation.

Relocation diffusion involves the movement of individuals [1 mark], taking the disease with them to new locations [1 mark] where it continues to spread through contact with then more people (e.g. airline passengers) [1 mark]. Credit other valid points, including an example of a disease such as SARS for [1 mark]. Responses which do not include a diagram may not be awarded more than [3 marks].

Numerous factors can result in more food becoming available.

The first major group of factors is those related to the improved productivity and/or total production of food-related agriculture. These factors include: increased area under cultivation as a result of land clearance and/or irrigation; higher yields due to better technology (e.g. drip irrigation instead of flood irrigation), mechanization, improved varieties (including GM crops and livestock).

Distribution and storage is also important. More food may become available because less is lost or damaged in transit as a result of improvements in the distribution network (highways, rail, planes) or in the vehicles used (e.g. refrigeration). Improved packing methods may also be important. Subsidies to local farmers for food crops, and reductions in food exports may also raise the amount of food available locally. Equally, a rise in income may also increase the availability of food within some sectors of society. Increased food imports also play a part, and this means that increased availability of food may depend on the success of harvests a long way away from their eventual destination.

While changes of climate may bear some responsibility for increased food availability in some areas, this will normally be restricted to those areas which were previously suffering from a prolonged condition such as an extreme drought.

It is expected that responses reaching markbands E/F will consider a variety of factors, and support their ideas with accurate examples.

Marks should be allocated according to the markbands.

Most candidates understood obesity as the result of excessive food intake but references to the BMI were less common.

Well-recognized factors were included but there was failure to elaborate sufficiently for all four marks. 

A common error was the disease seemed to be travelling by plane to another country with no mention of the vector. Or people carrying malaria to another country and passing it on. Most candidates attempted a diagram of some sorts. Generally, the process of diffusion was not well understood and there were few diagrams that related well to the concept.

 Answers tended to be superficial and were narrowly focused, with few candidates being able to refer to a range of factors other than those related to the Green Revolution, which is hardly a recent phenomenon. Failure to examine in depth was the main issue with this question. Many concentrated just on improved productivity, for example, mechanization, high yielding varieties, and did not really explain how they led to more food availability.