List two possible variants in the molecular structure of unsaturated fatty acids.

State one reason to include fibre in the diet.

Describe the health consequences of a diet rich in proteins.

number of carbons (in the chain/length of chain);
number of double bonds (in the chain) / may be monounsaturated/ polyunsaturated;
cis/trans structure in unsaturated fatty acids / OWTTE;
location of double bonds;
counting inwards from opposite end of COOH group/omega 3/omega 7;

(bulk) may help regulate digestive process/peristalsis/prevent constipation;
may lower risk of colon/intestinal cancer/appendicitis/diabetes/cardiovascular disease;
may decrease hunger (helping with control of food intake);

quick drop in weight (through loss of body fluids);
important for children/pregnant/breastfeeding women;
loss of calcium ions in urine / possible risk of osteoporosis;
unbalanced diet / lack of essential nutrients;
e.g. essential vitamins/minerals/fibre;
possible rise in blood pressure;
release of ketones into bloodstream/ketosis (causing loss of appetite);
possible risk of kidney/liver disorders/stones/reduced functioning;
gout;

A2 (a) was well answered by most. Most candidates mentioned monounsaturated and polyunsaturated and some cis and trans.

The majority of candidates explained the importance of fibre in the diet with in-depth explanation, although some candidates gave answers without biological jargon, such as "fibres clean the guts".

Many candidates gave very long answers talking about the dangers of the fats associated to proteins (for example in beef) but did not make reference to the dangers of a protein-rich diet.