Dr Kashinath Dixit is a Consultant Physician and Diabetologist working at Central Manchester University Hospitals NHS Trust. His special interests include prevention and management of the complications of diabetes like cardiac, renal and sexual dysfunction. He is also one of the few Medical Andrologists in the UK and is the first Endocrinologist to obtain certification in Clinical Andrology from the European Academy of Andrology
Type 2 diabetes which is the most common form of diabetes (about 90%) is increasing at an alarming rate throughout the world. It is particularly a major problem in South Asians mainly due to genetic predisposition and lifestyle factors. The key abnormality underlying type 2 diabetes is known as ‘Insulin Resistance.’
Insulin resistance
Glucose absorbed into our blood stream after digestion of food is the main source of our energy. But it has to enter the cells of our body to produce energy. The transport of glucose into the cells is facilitated by a hormone called insulin which is produced by specialized beta cells of pancreas. Insulin resistance is a state when our body develops certain factors which can oppose the action of insulin. This essentially means that too much of insulin would be required to achieve its normal functioning. This causes burden on the insulin producing cells of the pancreas and predisposes to the development of diabetes and complications like heart attacks. Although insulin resistance can be genetic, the common causes are
· Obesity, especially abdominal obesity
· High saturated fat intake
· High refined carbohydrate intake
· Sedentary lifestyle
· Chronic stress
· Poor sleep
· Ageing
Vegetarian diet and insulin resistance
Vegetarian diet is becoming increasingly popular worldwide. India has got the largest vegetarian population in the world. Ancient Indian vegetarian cuisine, despite its regional diversity, was very scientific. Changing cuisines of modern times due to advancement in technology and availability of a variety of food items, have made vegetarian dishes much richer with potential to cause insulin resistance. As diabetes is increasing even in vegetarian population, there is now an urgent need for better understanding and planning of modern vegetarian diet to improve diabetes care of the vegetarian diabetics.
· The good aspect of vegetarian diet is that it is very easy to plan a low fat, low calorie and high fibre diet. Several research studies have shown that vegetarian diet can reduce insulin resistance and improve diabetes. Vegan diet which is completely devoid of animal products has been shown to be better than lacto-vegetarian diet.
· The down side is that vegetarians can end up eating more carbohydrates than normally required and this can increase the glucose load on our body. The other issue is that the requirements of protein and other nutrients like iron, calcium, vitamins etc may not be met. Fried savouries not just add to the fat and calorie intake but also increase the salt intake.
· The most detrimental aspect of vegetarian diet, especially for South Asians is the availability of traditional sweets like Gulab Jamun, Jalebi etc. and also the newer innovative sweets, all of which are high in saturated fats, sugar and calories.
Aims of eating in order to reduce insulin resistance
· To feel energetic not only to carry on day to day activities but also to undertake regular physical exercise
· To achieve good day to day blood glucose control
· To achieve good cholesterol control
· To achieve and maintain normal body weight, especially normalise waist circumference - less than 90 cm (35.5 inches) for men and less than 80 cm (32 inches) for women
Strategies for healthy eating
Mindfulness in eating
The starting point is to try and understand our attitude towards diet and eating. A good strategy for this is to have a focussed week by deeply observing and recording everything about our eating in a food dairy. This should help us to explore the following
· What do we eat? Focussing on the nutritional quality of the food & beverages available at home, work place and at eat outs. What choices we make from these and why?
· How much we eat, how fast we eat and at what times? Focussing on the quantity of food and pattern of eating
· Why do we eat or drink beverages? Focussing on hunger and other triggers for eating like mood, tiredness, poor sleep etc.
· How active are we and how does that relate to eating?
· How is our sleep? what is its influence on our eating pattern?
Quantity of food
This depends on several factors like age, physical activity and weight or waist circumference. In simple terms if the waist circumference is above normal, quantity of food intake should be cut down gradually aiming to bring the waist circumference to normal.
Eating pattern
Food should be chewed well and eaten slowly. It is better to eat three meals a day and space out breakfast, lunch and evening meal. It is very important not to skip meals.
Quality of food
Carbohydrates
Two main types of carbohydrates are sugars and starchy carbohydrates like rice, wheat, oats, millets etc. All carbohydrates are converted to glucose after digestion but their effect on the pattern of rise in blood glucose levels after eating are different. Some carbohydrates like sugars, white rice, potatoes etc. produce a rapid rise in blood glucose and are known as high glycaemic index foods. The carbohydrates which produce a gradual rise in blood glucose are known as low glycaemic index foods and these include wholemeal chapattis, bulgar wheat, oats, basmati rice, pulses, nuts, vegetables including yam, plantain, cassava etc. The choice of carbohydrates therefore should be that of low glycaemic index. It is important not to overcook food in order to maintain low glycaemic index of carbohydrates. In general, starchy carbohydrates should constitute one third of our plate at each meal as they are the major source of energy and are particularly important to provide glucose to our brain. Sugars and sugary drinks should be avoided.
Proteins:
One of the challenges with vegetarian diet is to get adequate amounts of good quality proteins without increasing carbohydrate intake. Pulses like lentils and beans are important source of proteins for vegetarians but only combining these with cereals like rice and wheat converts them into first class proteins. In this aspect our popular staple foods like kichadi, chapattis with dhal etc, are excellent. For lacto-vegetarians low fat milk, low fat yoghurt and butter milk are good sources of proteins.
Fats:
Saturated fats like butter and ghee should be cut down to a large extent. Unsaturated fats, especially monounsaturated fats like rapeseed oil, olive oil etc. should be chosen for cooking. A combination of these oils may be useful in adding variety to the dishes. Fried foods should be avoided as much as possible. Grilling, steaming or oven baking are healthier options instead of frying. If dairy products are used, low fat options should be chosen.
Vegetables:
The recommendation of eating five portions of vegetables and fruits a day should not be difficult for vegetarians. Green leafy vegetables must be included in the diet. Salads with raw vegetables should also form a part of every meal. High fibre content in the food reduces the absorption of carbohydrates and prevents quicker rise in blood glucose levels. It can also help in reducing cholesterol. We should aim to eat vegetables comprising of at least one third quantity of each meal plate.
Spices:
Many of the spices like fenugreek, cinnamon, and turmeric have been shown to be good for our health. Therefore these can be used rather liberally in our cooking.
Nuts:
It will be very good to add small amounts of unsalted nuts like walnuts, almonds etc. in our daily diet to improve the nutritional value of our diet.
Other important aspects of vegetarian diet
In addition to reducing sugar and fat, salt intake should also be reduced.
Nutritional assessment for possible deficiencies like vitamin B12, vitamin D, Iron, Calcium etc. should be discussed with the doctors and supplemented if necessary.
Elderly patients and those on insulin should monitor blood glucose frequently while modifying their diet and interact with their diabetes team closely to reduce medication safely. In this way, the major concern of hypoglycaemia can be avoided.
Vegetarian diet is very good for diabetics if planned well. It would be more beneficial in conjunction with physical activity and relaxation techniques.
Acknowledgements – Mrs Susan Curtis, Senior Dietitian, Manchester Diabetes Centre, Manchester.
