To help you understand how the foods we eat can play in a role in preventing the onset of type 2 diabetes, we spoke to Dr Raymond Tso, medical director at Sun Life.
Is there a diet to prevent diabetes?
The short answer is no. “There is not one optimal diet,” Dr Tso says. “The optimal diet is whatever one can follow and sustain to achieve optimal body fat percentage and avoid obesity.”
There are however some eating patterns that can help reduce the risk of developing type 2 diabetes.
The best-known is the Mediterranean diet. It focuses on the daily consumption of vegetables, fruits, whole grains and healthy fats, moderate consumption of dairy and limited red meat.
Dr Tso recommends a simple eating pattern of his own: “Avoid refined carbohydrates and sugars. Eat lots of fibre, balanced with lean meat or a good quality plant-based protein. And practice portion control.”
What about rice?
The question is especially poignant in Asia where white rice makes up a large proportion of daily energy intake. The multinational, multiethnic Prospective Urban Rural Epidemiology study suggests eating more than three cups a day of white rice significantly increases the risk of diabetes compared with eating lower amounts. But again, there is no black or white answer to this question.
“It depends on the calorie intake,” Dr Tso says, “and optimal glycemic control,” – the medical term for the typical levels of blood sugar in a person with diabetes.
Foods with a low glycemic index (GI) include green vegetables, most fruits, kidney beans, lentils and bran breakfast cereals. Foods with high GI include white bread, potatoes and white rice. Brown rice, however, has a medium GI and is much more suitable for people concerned about the prevalence of type 2 diabetes.
Can popular new diets help prevent or manage diabetes?
Low-carb and very low-carb diets that involve a strict elimination of all carbohydrate-containing foods including fruits, grains, starchy vegetables, dairy products and sugar are effective for short-term weight loss and may help lower blood sugar levels. But they are difficult to follow for long periods.
Low-carb diets also have potential negative side-effects like fatigue, flu-like symptoms, and nutrient deficiencies. What's more, they eliminate a lot of healthy dietary fibre that can help reduce the risk of diabetes, heart disease and some cancers.
Intermittent fasting where people choose to not eat anything for 16 hours at a time, two days per week or every second day have also become increasingly popular.
Studies show intermittent fasting has the potential to reduce blood sugar and promote weight loss. But there is not enough evidence to show it is an effective alternative to healthy eating patterns. And like low-carb diets, intermittent fasting requires a great deal of discipline and are difficult to follow in the long-term. What’s more, they are not suitable for people taking certain medications that cannot be consumed on an empty stomach. If you’re living with diabetes, speak with doctor before starting any of these diets, Dr Tso says.
What's the best diet for those already living with diabetes?
The dietary patterns that help prevent and delay the onset of type 2 diabetes can also help with diabetes management.
Low GI carbohydrates like nuts, porridge, sweet potatoes and soy products raise your blood sugar less compared to those with medium GI like basmati rice, wholemeal bread, honey and orange juice.
High GI carbohydrates are those people already living with diabetes need to avoid: white rice, as mentioned, as well as American-style short-grain brown rice and Japanese-style sushi rice.
Measuring your blood sugars at home can also help determine the right type and amount of carbohydrates you can tolerate. A registered dietitian can help you interpret your blood sugar numbers and make suggestions on what changes you can make to your diet to improve your diabetes management.
“But while lifestyle modifications like eating habits are the key to reducing the risk of diabetes,” Dr Tso says, “one should not over-rely on it and hope their disease can be controlled without appropriate medications.”