The headline ‘Fat to blame for half a million cancers a year’ (November 27) might be interpreted at a glance that dietary fat, rather than sugars and other high glycaemic carbohydrates, are mainly responsible for obesity and its complications, rather than the other way round.

It has taken decades to realise that obesity and its life-shortening complications are much more closely related to carbohydrates than to dietary fats.

The responsible carbohydrates are sugars in foods, fizzy drinks and fruit juices as well as foods made from refined grains, rice and potato. Drinks with artificial sweeteners are also under suspicion.

These foods and drinks raise blood insulin; this is a growth hormone which increases cancer risk.

There is also increasing suspicion that too much dietary carbohydrates, rather than animal fats, increase risk of cardiovascular disease and of a ‘bad’ blood cholesterol profile. Interpretation of blood cholesterol results is increasingly confused because the significance of routine LDL and HDL cholesterol measurements are increasingly controversial.

The largely ignored blood triglyceride level may be a more reliable indicator of risk (the higher it is) for cardiovascular disease and diabetes and a high triglyceride blood level appears to be more related to dietary sugars and carbohydrates rather than to fats. This is the opposite of our decades-long conventional medical wisdom.

The amount of food intake is also important for tackling obesity. Experiments on different animals, from mice to monkeys, during these last few decades have all shown the same result: the more they eat, the less they live.

Human biology would be expected to behave in a similar way, supporting the notion that gluttony is one of the deadliest sins. Using smaller serving plates helps cut down on meal portions.