16th March 2018 — ‘One size of diet does not fit all’ was the core message from experts who have compiled the 2018 Diabetes UKevidence-based nutrition guidelines for the prevention and management of diabetes. They were speaking at the recent Diabetes UK Professional Conference 2018.
The guidelines, which provide an update to the 2011 version, were prepared earlier than the usual 10-year gap because of the wealth of data and extent of change in the field of diabetes in recent years, say the researchers.
Introducing the new guidelines were Dr Pamela Dyson, from Oxford University, and Douglas Twenefour, registered dietitian and deputy head of care at Diabetes UK. A summary was published online in Diabetic Medicine, and the full guidelines are available on the Diabetes UK website.
The guidelines cover education and care delivery, prevention of type 2 diabetes, glycaemic control for type 1 and type 2 diabetes, cardiovascular disease risk management, management of diabetes-related complications, and other considerations including comorbidities, nutrition support, pregnancy and lactation,eating disorders, micronutrients, food supplements, functional foods, commercial diabetic foods, and nutritive and non-nutritive sweeteners. They cover adults with diabetes as, for children, Diabetes UK has adopted guidelines by the International Society of Paediatric and Adolescent Diabetes (ISPAD).
Of note, recommendations are made in terms of ‘foods’ rather than nutrients wherever possible. Evidence around physical activity and alcohol intake, where appropriate, are included, as is information on how the guidelines can be best delivered and the role of dietitians, said Douglas Twenefour.
He pointed out that the individualised approach, epitomized in the new guidelines, was a key recommendation that extends to diet, physical activity, and surgical and medical strategies for people with diabetes.
Particularly noteworthy in the new 2018 guidelines is the recommendation forweight loss soon after diagnosis of type 2 diabetes in the hope of inducing remission, as well as a long section on diabetes in ethnic minorities.
“These groups have not received much attention in the past, due to very few randomised controlled trials to inform recommendations,” remarked Dr Dyson. “We know ethnic minorities in the UK, in particular South Asian and [African-Caribbean] groups, are three to four times as likely as whites to get type 2 diabetes.”
The guidelines also recognise that patients with type 2 diabetes are living longer and therefore experiencing more chronic diseases that would also benefit from a healthier diet, she noted. “For type 2 diabetes, we aim for weight loss, improving glycaemic control, and improving cardiovascular disease risk.”
Nutrition can be a stand-alone therapy, although not for type 1 diabetes, which requires insulin and lifestyle interventions, she stressed.
Aim for at least 5% weight loss, where appropriate.
Key recommendations for lifestyle interventions: restrict energy intake, increasedietary fibre intake, reduce total and saturated fat intake, increase physical activity.
Dietary patterns associated with reduced risk of disease: Mediterranean-style, DASH (Dietary Approaches to Stop Hypertension), vegetarian and vegan, Nordic healthy diet, moderate carbohydrate restriction.
Include foods associated with reduced risk, such as wholegrains, some fruit, green leafy vegetables, yoghurt, cheese, tea, coffee.
Reduce foods associated with risk, including processed and red meat, potatoes, sugar-sweetened beverages, refined carbohydrates.
Offer culturally tailored, multicomponent lifestyle interventions to reduce risk of type 2 diabetes.
(Courtesy of Dr Pamela Dyson)
A host of new diets
Low carbohydrate diets have recently received attention, and the new guidelines address these along with the array of other novel diets that have gained popularity.
“All advice and support needs to be individualised because there is no evidence to say there is one optimal diet for people with type 2 diabetes,” Dr Dyson pointed out, adding that although the optimal levels of fat or carbohydrate are unknown, studies show that patients had better outcomes when a dietary intervention was used.
Dr Dyson continued by noting the lack of diet-related weight loss evidence beyond 3 to 6 months. “There’s a whole raft of different strategies and no one magic diet, but there is a way of eating that suits your life, family, and culture, and it could be a Mediterranean-style, low-glycaemic, or low-carb diet,” she said. “They all work, so we need to give people the choice, and if the first option doesn’t work, move on to the second.”
The guidelines take into account the latest results from the Diabetes Remission Clinical Trial (DIRECT), presented at the International Diabetes Federation (IDF) Congress 2017.
In that trial, patients with type 2 diabetes reversed their condition if they stuck to a very low-calorie liquid diet of around 850 kcal/day for 3 to 5 months, and then gradually reintroduced food, with ongoing support.
Diabetes remission was achieved overall after 1 year in 68 (46%) of participants — almost half — in the intervention group, and 6 (4%) participants in the control group. “Based on these results, it is possible to say that in patients with newly diagnosed [type 2] diabetes, there is around a 50% chance of remission, if thislow calorie diet is followed,” remarked Dr Dyson.
UK ethnic minorities disproportionately affected by type 2 diabetes
Also speaking at the conference was Dr Louise Goff, senior lecturer, King’s College London, who discussed the new recommendations and type 2 diabetes in ethnic minorities in the UK.
“Diabetes is diagnosed on average 10 to 12 years earlier in Afro-Caribbean and South Asian populations. Around 30% of South Asian patients with diabetes are under 40 years old, compared with 9% of white European patients. South Asians and [African-Caribbean] patients are living for a long time with type 2 diabetes,” Dr Goff observed.
She pointed out that these ethnic minorities also tend to have cultural barriers that limit access to healthcare, and noted a lack of cultural competency among healthcare professionals, which can have a knock-on effect in terms of diabetes prevention and management in these groups.
“Evidence suggests that culturally sensitive programs…ultimately improve patient outcomes, and diabetes prevention programs have been shown to improve engagement and be effective in ethnic minority groups, but there is a paucity of them in the UK,” she noted.
“We need to partner with our communities to nurture cultural tailoring of health care and cultural competency among health care professionals to improve engagement with patients,” Dr Goff asserted.
For example, the guidelines specifically include a section on diabetes management during Ramadan.
“Structured advice on diet, physical activity, and medications management reduces hypos and weight gain.” She referred to the results of the Ramadan Education and Awareness Program in Diabetes that showed significant and prolonged (12-month follow-up) benefits for HbA1c and weight gain.
Maintaining weight loss, glycaemic control, and CVD prevention
Dr Duane Mellor, from the University of Coventry, discussed the recommendations for glycaemic control and cardiovascular disease (CVD) prevention. For type 2 diabetes, there is a continued focus on weight management, but a move from focusing on just energy to food-based advice linked to dietary patterns.
Concerning individualised weight management, he focused on the difficulties associated with weight loss maintenance.
“This is where we need to take a longitudinal approach, and we’re unsure here, but we do know that the greater the weight loss, the greater the chance of remission. Weight management and glycaemic control are a toolkit. There isn’t one approach for everyone,” he emphasised.
Regarding CVD prevention, there is a shift from recommendations about nutrients to eating patterns, and how the evidence fits together.
“Quality of food in the diet, such as replacing saturated fat, is important so a food-based approach is more successful. In the Mediterranean [diet], they use olive oil and do not replace saturated fat with refined carbohydrate,” as the latter can increase risk, said Dr Mellor.
And fat is currently a hot-button issue, he reflected. “Study findings suggest that any effects of fat on CVD risk are likely derived from the type of fat rather than the amount.”
Turning to diet types, he highlighted the Dietary Approaches to Stop Hypertension (DASH) diet and the difficulty adhering to it. “You’d need to be a motivated individual because there’s a lot of change in the diet. It might not appeal to some, so in terms of individualisation we might want to think about how we move people towards the approach, rather than presuming it is all or nothing.”
Asked to comment on the new dietary guidelines for Medscape Medical News, Dr Dinesh Nagi, chairman of the Association of British Clinical Diabetologists, and consultant at Mid Yorkshire NHS Trust, said: “These updated guidelines provide a highly valuable resource for health care professionals who work in this field, and I have no doubt they will enable them to provide an individualised nutritional plan to people with diabetes.”
“They are also a timely reminder to all of us working in specialist and primary care of the importance of nutrition, both in the prevention of type 2 diabetes and day to day management of diabetes.”