The second half of the 20th century saw a great rise in type 2 diabetes  – a disease which considerably reduces the quality of life and often leads to disability and premature death. About 4 to 6% of the European population suffers from it. Despite the ever new methods of treatment, a properly composed diet and systematic physical exercises are still the most effective therapy element.

A characteristic symptom of diabetes is a heightened concentration of sugar in blood, which causes the development of dangerous sclerotic changes in blood vessels in the brain, heart and lower limbs, as well as kidneys, eyes and the vessels delivering blood to nerves. As a result of intensifying complications in the circulatory system, the risk of illnesses such as high blood pressure, stroke, coronary heart disease, sclerosis of the lower limbs, as well as kidney and eyesight diseases and degenerative changes in the nervous system. However, life with diabetes is possible and, what is more, one can be fully active on condition that specified nutrition rules are observed and the necessary portion of physical activity is taken.

About the exercises first

Interest in physical activity dwindles among people with diabetes, and this is not without a reason. As a result of insulin deficiency, the production of muscle proteins in the body decreases, which leads to general weakness. At the same time, ailments of peripheral nerves accompanying diabetes impede the correct motor coordination, reduce the force and tension of muscles, and as a result of intensified sclerotic changes, muscles are also ischemic. Even people who try to exercise despite these obstacles can experience serious disturbances in the form of sudden rise or fall of sugar level in blood or appearance of excessive quantity of ketone compounds. Is taking exercise in the case of diabetes advisable? The answer can be only one – yes – on condition, though, that it is taken in a well-considered way.

Hyper and hypoglycemia

Under the influence of increased muscle activity, there are significant changes in the hormone system in the body; the release of hormones such as glucagone, growth hormone or corticosteroids increases. All these substances raise the sugar level in blood, which can lead to dangerous hyperglycaemia with diabetic patients. The uptake of sugar by muscles in diabetes is handicapped, as a result of which the main source of energy during physical activity is fat, which undergoes semi-burning and changes into the so-called sour ketone compounds, as it cannot satisfy the body’s energy needs. There are tendencies to develop a dangerous condition of metabolic ketoacidosis. The metabolic disorders described above occur only under the influence of too intensive physical exercise. Another type of disorder can be a situation which is quite to the contrary, when there is a sudden drop in the sugar level in blood under the influence of effort, which can turn out to be equally dangerous. This type of situation occurs most frequently among patients treated with insulin. With healthy people, the release of insulin by the pancreas is halted, and its concentration in blood is very low. Insulin injections cause its sudden absorption into the blood stream, as the blood flow through skin and subcutaneous increases. Therefore, with patients treated with insulin there can be an excessive rise of the hormone level in blood and sudden drop in sugar level during physical activity. However, hypoglycaemia symptoms can occur only under the influence of excessive effort, which is why diabetic patients and those treated with insulin preparations should consult their GP before taking up physical activity, as the safety and effectiveness of exercises depends on:

• the type and dose of insulin used
• time between taking the preparation and starting physical effort
• amount of carbohydrates taken with a meal preceding the training session
• duration and intensiveness of workout

Why exercise?

Despite the visible limitations and difficulties, which the training diabetic, systematic physical activity turns out to be one of the most important and effective methods of treatment, on condition, though, that the training sessions take place in a well-considered way. It is clear that there is a partial or complete deficiency of insulin in diabetes, as well as a reduced sensitivity of cells to its orders. As a consequence, sugar cannot reach muscles and its excess moves around in the blood stream. Although insulin injections deal with this problem in part, there are still some hindrances, as muscle cells are not sensitive enough to its presence. However, everything changes during physical workout. During muscle activity, the body does not practically need insulin to find a proper place for sugar. Moreover, the sugar reserves in the muscles increase as well as the cell sensitivity to insulin does, which alleviates a number of metabolic disorders induced with excessive amounts of sugar in blood. The diabetics who exercise regularly can count on the fact that the need for insulin will decrease with them. At the same time, the whole circulatory system improves, blood coagulability decreases, as well as the concentration of the dangerous type of cholesterol does, with the increase of its favourable fractions, which prevents formation of sclerotic changes in blood vessels. There is also an improvement in the capacity of the heart, lungs and the motor system. The waistline becomes shorter and muscles begin to grow. The benefits of exercise are visible not only during physical effort but also for up to 48 hours after its completion. It has been stated that glycaemia begins to appear within 3 to 5 days of a training session, that is why diabetics should muster their energy to do exercise at least three times a week. We should remember, though, that the exercise session should not be too long and intensive, at best the exercise should consist in walking of medium intensity, cycling, slight jogging, swimming or dance.

Diet in diabetes

As diabetes is connected with insulin deficiency and strong disorders in the metabolism of carbohydrates and fat, proper dietary recommendations are necessary to relieve a number of the unfavourable changes. The most important issue when setting a diet is the specification of general need for calories. According to the norms of FAO and WHO, the following recommendations are suggested:

• persons with correct body mass, bed-ridden (the sick): 20 – 25 kcal for  1kg of body mass
• healthy, non working persons with correct body mass: 25 – 30 kcal for 1kg of body mass
• healthy working persons with correct body mass: 30 – 35 kcal for 1kg of body mass
• healthy hard working persons with correct body mass: 35 – 40 kcal for 1kg of body mass

The above recommendations do not refer to the current but to the proper body mass. People with obesity should receive relatively smaller number of calories, and underweight people should have a higher calorie intake. Reducing the energy value should take place at the expense of carbohydrates (sugar) and fat.

What about sugars?

Undoubtedly, it is not only the overall consumption of carbohydrates, which should be reduced in the diet, but first and foremost the consumption of simple, which increases the amount of insulin in the circulatory system sugars should be limited. This applies not only to saccharose in sugar bowls, but also all kinds of sweetened drinks, fruit juices, sweets or certain fruits. It should be also remembered that carbohydrates are not to be taken on an empty stomach but possibly after main meals. Then, sugars blend with other meal ingredients and this way their transport into blood slows down. Excess of sugar in the circulatory system does not only cause the increase of glycaemia, but first and foremost it increases the concentration of triglicerides and cholesterol, which is known not to be indifferent to the course of sclerosis processes. Also, the total pool of carbohydrates should be skilfully managed. Their consumption should be increased in the morning and around noon, and should be decreased towards the evening. Soluble fiber can be a good addition to meals, and its best sources are oat bran and raw vegetables. Fiber hampers and slows down the absorption of sugar in blood, as well as reducing the level of the unfavourable cholesterol. The amount of carbohydrates in the diet should not be lower than 150g, as otherwise dangerous acidosis may ensue. The optimum dose is 250g, and only in the case of people doing hard physical work the amount of 300g of carbohydrates can be exceeded.

The demand for fat and proteins

Since in the case of diabetes we see an accelerated sclerosis process, we should draw particular attention to the appropriate supply of fat in the diet, both in terms of quality and quantity. Blood vessels are sensitive to the presence of saturated animal fat in the first place, therefore its consumption should be limited to the minimum. What should be avoided are fatty types of meat, pork-meat articles, offal as well as fatty dairy products. The allowed amount of fat (ca. 1g for 1kg of proper body mass) should come from plant oils and sea fish – products which contain mono and polyunsaturated fatty acids which are beneficial to the organism. Fats containing monounsaturated fatty acids, the best source of which in the diet is olive oil, are particularly significant in sclerosis prevention. Instead of meat, our tables should offer fish, which are an invaluable source of omega-3 fatty acids, which are beneficial for the body. All dishes should be cooked or steamed, and the allowed amount of fat should be given in a raw form, as a salad dressing for instance. The diet for diabetics should make special allowance for increased protein consumption, which is an invaluable building agent of muscles. The demand for this ingredient is increased by ca. 50% compared to healthy people. Its main source should be lean meat, pork-meat articles, fish and dairy products. It should be also remembered that the increased amount of proteins in the diet favours reduction of redundant fat, as proteins strongly accelerates metabolism and stimulates the hormone system which favours burning of fatty acids. The demand for vitamins and minerals should be covered with consumption of fruit and vegetables, the amount of which in the diet should not be lower than 350 g per day, excluding the potato.

Dariusz Szukała