The most focused area of research has clearly highlighted the importance of nutrition, body weight and physical activity as the three most easily identifiable causes of pre-diabetes.
A high saturated fat diet, obesity and low levels of exercise greatly increase the risk. The opposite is also true. A low fat diet high in fruit and vegetables is protective, maintaining an ideal body weight is important and taking regular exercise protects against pre-diabetes and the metabolic syndrome.
It is important, I think, not to be judgmental on any individual basis. Many of the reasons for poor nutrition are driven by national and governmental agendas. It is also true to say that our impression of people’s weight can also be strongly influenced by our narrow experiences within our own population group. It is simply not true to say that people who develop Type 2 diabetes are always overweight people who eat a bad diet.
The fact that slim people can get pre-diabetes can be examined further by considering the very definitions of the metabolic syndrome. These have had to recognise and adapt to ethnic diversity. The presentation of abnormal fasting glucose levels, for example, seems to happen in Chinese communities at much lower waist circumferences compared to European/ Caucasian populations.