Diabetes is the No. 6 leading causes of deaths in the United States, according to 2001 data from the United States National Center for Health Statistics.
Type 2 Diabetes Diet
Here, we focus on the role of diet and exercise in the management of Type 2 diabetes. In particular, we will take a look at the way in which diet and exercise can improve:
Blood glucose levels
Blood glucose levels are mainly kept in check by insulin. Type 2 diabetes usually occurs as the result of a combination of problems with insulin activity (insulin resistance) and insulin secretion. Diet and exercise can help to combat both of these problems.
The majority of people with Type 2 diabetes are ?insulin resistant?. This means that the insulin that is produced does not work very efficiently and large amounts are needed to keep blood glucose levels down. If the beta cells are under too much strain they may not be able to produce these large amounts of insulin; the blood glucose levels rise and diabetes results. People who are overweight and/or inactive tend to be more insulin resistant than lean people who exercise regularly.
The opposite of insulin resistance is insulin sensitivity. The more sensitive the body is to insulin, the less insulin is needed to control blood glucose levels.
The body can be made more sensitive to its insulin in a number of ways:
A few simple changes to your eating and exercise habits can make all the difference.
If insulin sensitivity is increased through weight loss and an increase in activity level then less insulin is needed to keep blood glucose levels controlled. If less insulin is needed, then less strain is put on the beta cells.
Food, blood glucose and insulin
Carbohydrate foods have the greatest direct effect on blood glucose levels. Carbohydrates are broken down into glucose by digestive enzymes. The glucose is then absorbed from the intestine into the bloodstream (usually 1 ? 2 hours after eating) and this causes the blood glucose level to rise after a meal. Insulin is needed so that the body?s cells can take this glucose from the bloodstream and either use it for energy or store it for later. People who do not have diabetes will produce just the right amount of insulin to cope with the rise in blood glucose that occurs after a meal. Insulin on demand allows the person without diabetes to keep blood glucose levels within the normal range, even after a meal rich in carbohydrates.
If you have Type 2 diabetes then your body no longer produces enough insulin on demand to keep blood glucose levels within the normal range. Many people with Type 2 diabetes do not produce enough insulin to cope with the sharp rise in blood glucose that happens after a meal.
Choosing food types that are more slowly digested can reduce the ?post-meal spike? in blood glucose, which in turn reduces the demand on the beta cells for insulin.
So, a three-pronged attack on the situation can help you to control your blood glucose levels:
Many people with Type 2 diabetes have unhealthy levels of blood fats ? this is commonly referred to as an unhealthy ?lipid profile?. Too much of the wrong types of fat in the blood increases the risk of heart disease and circulation problems. Another important aim of diet and exercise in the management of your diabetes will therefore be to help keep your blood lipid levels normal.
Reducing your intake of saturated fat and not drinking too much alcohol can help to bring down levels of cholesterol and triglycerides in the blood.
Do note that, in addition to healthy eating, regular exercise can also help to improve your blood lipid profile.
Type 2 diabetes is often accompanied by high blood pressure and this increases the risk of diabetic eye and kidney damage, as well as heart disease and circulation problems. Regular exercise, eating a low-fat and low-salt diet, and reducing alcohol intake can all help to lower blood pressure.
Different food types
You will need to learn about different food types so that you can make healthy choices when it comes to meal planning.
The overall effect of a meal on the blood glucose level will depend on the different types of foods making up the meal. Carbohydrate foods have the greatest effects on blood glucose levels because they are mostly digested to glucose, which is absorbed from the intestine straight into the bloodstream. However, proteins and fats in the diet do affect blood glucose levels too.
You will need to pay attention to the amount and type of fat that you eat. Fatty foods tend to be high in calories and eating too much of some types of fat can raise your blood fat levels, increasing the risk of heart disease and circulation problems.
Different types of carbohydrate foods are digested at different rates and therefore have different effects in terms of raising the blood glucose level after a meal. Some foods are quite rapidly digested to glucose (e.g. cornflakes), whilst others take longer for the glucose to hit the bloodstream (e.g. All-BranTM). The effect of different carbohydrate foods on blood glucose levels has been quantified by the Glycaemic Index (GI). Foods with a low GI cause less of a spike in post-meal blood glucose than those with a high GI.
It is still widely believed amongst the general population that people with diabetes should avoid eating sugar because it causes a rapid increase in blood glucose levels. This is not true! Table sugar, which we sprinkle on our cornflakes, actually causes less of a spike in blood glucose than the cornflakes themselves. Sucrose*, surprisingly, has a lower GI than cornflakes.
As part of healthy eating, we are all advised to cut down on sugar ? this is because it has little nutritional value, it does little to satisfy the appetite and it?s a source of ?empty calories?.
Table sugar is not the same as glucose. Table sugar is called sucrose and is a disaccharide ? it contains two sugar molecules: one fructose and one glucose. Table sugar needs to be broken down by digestive enzymes before the fructose and glucose can be absorbed. Glucose is absorbed quickly because it does not need to be broken down (digested) first.
The most significant effect of fat on blood glucose levels is probably to slow down the rise in blood glucose after a meal. Fat delays the rate at which the stomach empties ? this has the knock-on effect of slowing down the absorption of glucose from digested carbohydrate foods. You might think that this is a good thing, but remember that a high-fat diet is not necessarily a healthy diet.
There are different types of fats ? some can be beneficial to our health, but others can increase the risk of high blood pressure and heart disease. Too much saturated fat and cholesterol in the diet can result in unhealthy levels of blood fats. However, monounsaturated fats may improve your lipid profile.
Excess protein in the diet that is not needed by the body is converted to glucose by the liver. This means that consuming large amounts of protein can result in an increase in blood glucose levels several hours after eating.
Currently there is no strong evidence that a high protein diet is particularly beneficial for people with diabetes. Remember that animal sources of protein - meat and dairy products - are high in saturated fat.
Putting the theory into practice
So far, we have looked at the different ways in which diet and exercise can help you to manage your diabetes. This is all well and good ? but how do you actually go about using this information? There is a lot to consider and you may well be feeling totally overwhelmed by it all. So where do you start?
Talk to your dietitian. Together you should be able to work out a food plan that is suitable for you and takes into account your tastes and lifestyle, in addition to financial and cultural considerations.
Look at your usual eating and exercising patterns and see where you could make small changes for the better. Set yourself achievable targets.
Use blood glucose monitoring to find out whether your diet and exercise approach is working; make a note in your diary of the changes you made and learn from experience. The most informative times to test are first thing in the morning, before eating and 1 ? 2 hours after your meal.
If you are taking tablets to help control your blood glucose level then you will need to eat regular meals and make sure that you take your tablets at the times prescribed. Remember, your tablets will only be successful in controlling your diabetes if you pay attention to your diet and engage in regular exercise.
If you are injecting insulin to help control your blood glucose levels then you should also look at the principles of dietary management in Type 1 diabetes ? this will help you to understand more about the relationship between your blood glucose levels and the food that you eat, and the insulin that you inject.
If you take certain tablets or have insulin injections?
An additional role of diet in managing diabetes is preventing low blood glucose levels (hypoglycaemia). This is particularly important if you take tablets that increase your insulin production, or if you have insulin injections.
Some insulin and tablet regimens require you to have snacks in between meals in order to prevent hypoglycaemia. Snacks are not always necessary though, so check with your doctor and/or dietitian to see if you need to snack between meals.
Delayed or missed meals are probably the most common cause of hypoglycaemia. Take steps to avoid low blood glucose levels if you know that you are not going to be able to eat your usual meal. Have an extra snack to keep you going and keep an eye on your blood glucose level.
A bedtime snack is, however, essential for all people who have insulin injections. This ensures that blood glucose levels don?t fall too low during the night.
Snacks are also very important before exercising, especially if the activity does not form part of your regular daily routine. This is to prevent exercise-induced hypoglycaemia.