•Pay regular visits to your care team, which should include your medical doctor, dietitian, optometrist and podiatrist, among others.
Healthy eating habits
Food forms an important part of everyone’s life – including those with diabetes – and it should always be pleasurable. The food we eat should also have a high nutritional value. When you have been diagnosed with diabetes, you will be forced to review and adapt your eating habits, which will also have advantages for the maintenance of your body.
Guidelines for good nutrition
The South African Food-Based Dietary Guidelines were revised in 2012 and published in 2013. They are easy to follow and include the following:
•Eat a variety of foods every day and distribute the food evenly in meals that are spaced over the entire day.
•Make starchy food part of most of your meals. Eat more low-GI starchy foods.
•Have at least five portions of vegetables and fruit every day.
•Have cooked dry beans, split peas, lentils and soya regularly.
•Have low-fat milk, maas, yoghurt or cottage cheese every day.
•Fish, chicken, lean red meat or eggs can be eaten daily depending on your budget.
•Use fats sparingly. Choose vegetable oils rather than hard fats. Choose mono- and polyunsaturated fats more often.
•Get into the habit of drinking plenty of clean, safe water every day.
•Use salt and foods high in salt sparingly.
•Use sugar and foods and drinks high in sugar sparingly and in consultation with your medical doctor and dietitian.
•Be more active and keep your body weight under control.
•In addition, if you drink alcohol, drink sparingly and in consultation with your medical doctor and dietitian.
The use of food exchange lists
To make it easier to choose suitable foods for balanced meals and to control blood sugar effectively, food exchange lists are recommended. There are six exchange lists and each one lists foods in specific quantities. All these food items – in defined portions – supply more or less the same amount of energy, fat, carbohydrate and protein and can therefore be used interchangeably in the meal plan. The items in each list have a specific function and no single food group can supply all your nutritional needs. This means you need to consume foods from all six exchange lists to meet your nutritional needs. The food exchange lists are a useful aid when you need to adjust your insulin dose based on the calculated amount of carbohydrates in one of your meals.
The glycaemic index (GI) can also be used very effectively in combination with the food exchange lists.
The carbohydrate (CHO), protein, fat and energy contents of the food items in each exchange list are as follows:
| Food exchanges | CHO (g) | Protein (g) | Fat (g) | Energy (kJ) |
| Milk– 1 full-cream milk– 1 low-fat milk– 1 fat-free milk | 121212 | 889 | 85- | 640525340 |
| Protein– 1 medium-fat protein– 1 low-fat protein– 1 plant protein | --8 | 774 | 531 | 310230230 |
| Starch | 15 | 2 | - | 275 |
| 1 free vegetable1 medium vegetable | Minimal7 | Minimal2 | -- | Minimal150 |
| 1 fruit | 15 | - | - | 250 |
| 1 fat | - | - | 5 | 190 |
Carbohydrates and diabetes
Carbohydrates are included in a balanced diet in the form of different sugar-containing foods and sugar products, such as jam, as well as starchy food like bread, grains, legumes, vegetables, fruit and milk. Carbohydrates are digested by the body into single sugar molecules such as glucose, fructose (fruit sugar) and lactose (milk sugar). The part that is not digested is called fibre. Fibre promotes peristalsis (gut movements) and combats constipation. If no carbohydrates are eaten, proteins (which are actually a building material) and fats are used as sources of energy. Carbohydrates therefore ensure that the proteins in your diet are used primarily for repair and maintenance of the body.
Carbohydrates are not just an important source of energy for your muscles – in the form of glucose they are the only source of energy for the brain. This is why it is important for diabetics to include carbohydrate foods at each meal.
When proteins and fat are eaten together with carbohydrates, the time required to digest the food combination is increased and the release of glucose into the bloodstream is consequently delayed.
To ensure good blood glucose control, it is important to understand that different carbohydrate-rich foods do not have the same effect on blood glucose levels, because they have different glycaemic indexes.
What is the glycaemic index (GI)?
The glycaemic indexes of different carbohydrate-rich foods are calculated values which indicate how rapidly and to what extent blood glucose is influenced by the intake of a specific type of food.
Carbohydrate-rich foods which are digested and absorbed slowly have a low GI and contribute to a more gradual release of glucose into the bloodstream, resulting in a lower insulin reaction and better blood glucose control. Because this is a gradual process the digestive tract is not emptied so rapidly, delaying the sensation of hunger.
Carbohydrate-rich foods which are digested and absorbed rapidly have a high GI and cause a rapid increase in glucose in the bloodstream, resulting in an increased insulin reaction and/or insulin requirement because of the rapid increase in the blood glucose levels.
The digestive tract is emptied relatively rapidly, which causes hunger sensations to occur again soon after eating. If this large quantity of glucose in the blood is not effectively transformed into energy in the body cells, the circulating blood glucose levels remain high because of the absence of insulin or, as in the case of insulin resistance, this glucose is stored as fat in the body.
Carbohydrate-rich foods are divided into items with a low GI (55 or less), an intermediate GI (56 to 70) or a high GI (more than 70). From a practical point of view, carbohydrate-rich foods with a GI of up to 62 are regarded as foods with an acceptably “low GI”, based on the assumption that when they are combined with the other foods in a meal, they will be digested and absorbed at a slower rate.
In addition to better blood glucose control, a low GI diet also has other advantages. It protects against the development of obesity, and colon, prostate, ovarian and breast cancer.
Factors that influence the GI of foods
The following factors influence the digestion and absorption of carbohydrates, as well as the blood glucose level:
Cooking and gelatinisation of starch
When starch is cooked in the presence of water and heat, it causes swelling and gelatinisation of the starch granules (grains). This gelatinised starch contributes to faster and easier digestion by the enzymes in the digestive tract and this can then result in a higher GI.
Cooling and retrogradation of starch
Starchy foods that are cooked with moist heat, such as potatoes and maize (mealie) meal porridge, are more difficult to digest after they have cooled down, as a result of retrogradation of the starch. This starch resists rapid digestion and therefore contributes to a lower GI.
Types of fibre and fibre content
Water-soluble fibre (as in cooked dry beans, lentils, chickpeas, soya, etc.) lowers the GI because it delays the emptying of the stomach, while water-insoluble fibre (such as digestive bran) only lowers the GI when the food contains large quantities of this fibre.
Sugars
Not all sugars are absorbed at the same rate. Glucose is absorbed very rapidly and has a high GI (100), while fructose (fruit sugar) is absorbed more slowly and consequently