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Know your family medical history.
A family history of type 2 diabetes was associated with a higher incidence of diabetes reports a study in Diabetologia. The greatest risk was observed in those with two parents with type 2 diabetes and those whose parents had been diagnosed with diabetes at a younger age, an effect largely confined to a maternal family history.

Family history of diabetes increases the risk of pre-diabetes by 26 percent. 
Pre-diabetes can take two forms: impaired fasting glycaemia (IFG) where levels of glucose are higher than normal but not high enough to be classed as diabetes; and impaired glucose tolerance (IGT) where blood glucose levels are abnormal due to increased insulin resistance. When Fritsche and colleagues from the German Centre for Diabetes Research analysed the records of 8106 individuals who did not have type 2 diabetes, they found 2624 had IFG and/or IGT. When they went on to analyse whether having at least one first degree relative with diabetes was associated with pre-diabetes, they found that a family history of diabetes increased the risk for pre-diabetes by 26% when the analysis took account of age, sex, and BMI. Writing in Diabetelogia, they conclude: “We found that family history is an important risk factor for pre-diabetes, especially for combined IGT and IFG. Its relevance seems to be more evident in the non-obese.”

Weight gain when there’s a family history of type 2 diabetes. 

Professor Lesley Campbell. 

Healthy people with a genetic predisposition to type 2 diabetes gain more weight overeating over the short term than their non-genetically-prone counterparts. In a 28-day study undertaken at Sydney’s Garvan Institute of Medical Research, scientists set out to mimic the kind of overfeeding that typically takes place during feasting periods like Christmas. Seventeen (otherwise healthy) people with a family history of type 2 diabetes, along with 24 people without any family history, took part in the research. The groups were matched for age, weight and lifestyle. Each person was asked to eat 1250 calories (5230 kJ) a day beyond their energy requirements – all carefully calculated in advance. They were given a variety of high-fat snacks such as crisps, chocolate bars and dairy desserts to supplement their normal diets. Their weight, fat distribution and blood insulin levels were measured at the start of the project, after 3 days and at 28 days. On average, the people with a family history of diabetes gained over a kilogram more than the rest (3.4 kg as opposed to 2.2 kg) over 28 days. They also had more insulin circulating in their systems after only 3 days, before they showed any detectable difference in weight gain from the other group.

“It’s already well-known that relatives of people with type 2 diabetes are more likely to develop it themselves,” said Professor Campbell, senior researcher at Garvan and Director St Vincent’s Diabetes Services. “We wanted to challenge these individuals with overfeeding while they were still young and healthy, without any metabolic impairments. Our study shows just how quickly the body reacts to overeating, and how harmful it can be in susceptible people. While we expected differences between the two groups, we were surprised by the amount of extra weight the diabetes-prone group gained.”

At the end of the study, participants were helped to lose weight, with both groups being equally successful. The “biggest loser” came from the group with a family history of diabetes.

Nutritional strategies for preventing and managing type 2 diabetes. 

Professor Frank Hu. 

Writing in The Lancet, Professor Frank Hu and colleagues review the evidence on the dietary components and nutritional strategies for preventing and managing type 2 diabetes. “The quality of dietary fats and carbohydrates consumed is more crucial than is the quantity of these macronutrients,” they conclude. “Diets rich in wholegrains, fruits, vegetables, legumes, and nuts; moderate in alcohol consumption; and lower in refined grains, red or processed meats, and sugar-sweetened beverages have been shown to reduce the risk of diabetes and improve glycemic control and blood lipids in patients with diabetes. With an emphasis on overall diet quality, several dietary patterns such as Mediterranean, low glycemic index, moderately low carbohydrate, and vegetarian diets can be tailored to personal and cultural food preferences and appropriate calorie needs for weight control and diabetes prevention and management.”