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WHAT ROLE DOES DIET HAVE IN THE PREVENTION OF DIABETES AMONG WOMEN WITH PRIOR GESTATIONAL DIABETES? 

According to the International Diabetes Federation, 1 in 6 births in 2019 were affected by gestational diabetes.

Gestational diabetes is a form of diabetes that first occurs during pregnancy and usually goes away after a woman gives birth. However, women who have gestational diabetes during their pregnancy are at higher risk of developing type 2 diabetes in the future. Making lifestyle changes, such as eating a healthy diet and exercising regularly, can help to reduce this risk. Achieving and maintaining a healthy weight is also important.

To help determine what type of eating plan might best help women with previous gestational diabetes to reduce their risk of developing type 2 diabetes, a group of Australian researchers recently performed a systematic review of relevant studies, which was published in the January 2020 issue of the Journal of the American Academy of Nutrition and Dietetics. The review included twelve articles from four intervention and four observational studies.

The intervention studies didn’t show any clear benefits of different types of diet although there was a trend towards the beneficial effects of a low-glycemic index diet, a low-carbohydrate diet, and a diet in line with general population dietary guidelines. However, the authors note concerns about the quality of these studies, which were found to have an unclear or high risk of bias.

After adjusting for confounding factors, including body mass index (BMI), the observational studies showed a higher risk of type 2 diabetes and/or impaired glucose tolerance (pre-diabetes) in women who had higher intakes of branched-chain amino acids, total and haem iron, and a diet that was relatively low in carbohydrates and high in animal fat and protein. Women who were consuming diets high in fruit, vegetables, nuts, fish, and legumes but low in red and processed meats and sugar-sweetened beverages, were found to have a lower risk. Amino acids are the building blocks of protein while haem iron is the form of iron found in animal foods.

The authors conclude that there is a lack of high-quality evidence from randomised controlled trials to show what type of diet might be best for reducing the risk of type 2 diabetes in women with previous gestational diabetes. However, findings from observational studies show associations between several nutrients, foods and dietary patterns, which are in line with current dietary recommendations, suggesting that diet may play an important role in the prevention of type 2 diabetes among women with prior GDM. They highlight the need for further, large randomised controlled trials to confirm the benefits of dietary modification for reducing diabetes risk in these women.

In the meantime, eating plenty of fruit and vegetables, more fish and legumes in place of red meat, choosing vegetable fats (such as nuts, seeds, avocado and olive oil) over animal fats and limiting sugar-sweetened beverages is likely to be of benefit and very unlikely to do any harm.

Read more:

• International Diabetes Federation. Gestational diabetes. 
• D’Arcy E, Rayner J, Hodge A, Ross LJ, Schoenaker DAJM. The Role of Diet in the Prevention of Diabetes among Women with Prior Gestational Diabetes: A Systematic Review of Intervention and Observational Studies. J Acad Nutr Diet. 2020

   
Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).    
Contact: Via her website www.drkatemarsh.com.au.