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Type 2 diabetes: Nutrition

Scientific support: Theresa Kössler

A change in diet, together with physical activity, is the basis for the treatment of type 2 diabetes. This basic treatment is often sufficient in the early stages of the disease, meaning those with type 2 diabetes do not need any medication. This is especially true for overweight people with type 2 diabetes: They benefit especially from a more balanced diet and more physical activity through the accompanying weight loss and increased fitness levels.

A special diabetes diet or special foods are usually not necessary. Instead, similar to people without diabetes, an individually tailored, balanced, mixed wholefoods diet is suitable for people with diabetes.

People with type 2 diabetes should adjust and design their daily mealtimes so that they can be easily integrated into their everyday life . Everyone has different preferences, financial possibilities, or culture. Ideally, people with type 2 diabetes should seek advice on dietary changes from a physician or a qualified or certified nutritionist.

To ensure that the change in diet remains sustainable in the long term, the fun and enjoyment associated with food should not be lost. This is because short-term diets are usually unsuccessful.

How do I eat correctly with type 2 diabetes?

The diet for type 2 diabetes should always be balanced and varied and include nutrient-rich, low-processed foods with high levels of fiber. High-energy foods with added sugar and heavily-processed cereals, known as refined cereals, should be avoided as far as possible.

Similar to people without diabetes, many diets are suitable for people with diabetes. Alongside a mixed, wholefood diet, primarily comprised of vegetables, fruit, pulses, nuts, seeds, wholewheat products, low-fat milk and meat products and fish, other possible options include low-carbohydrate or low-fat diets, a Mediterranean-style diet, or a vegetarian or vegan diet. It remains unclear if there is a certain type of diet that is especially suited to people with diabetes in the long term.

Being overweight or obese promotes the onset of type 2 diabetes. Therefore, people who are overweight and have type 2 diabetes should lose between 5 and 10 percent of their starting weight. In various studies, scientists have shown that overweight people with type 2 diabetes were able to notably improve their blood sugar values by losing weight. In some cases, the values will return to normal levels, making medication no longer necessary.

Furthermore, being overweight or obese – alongside type 2 diabetes – can cause a wide range of complications that severely impair quality of life. These include, for example, fat metabolism disordershigh blood pressure, cardiovascular diseases, tumor, kidney, and lung diseases, as well as mental illness. Weight loss can prevent the onset of these complications and improve quality of life.

To help with weight loss, overweight people should consume less energy than they burn. This can be achieved by eating less energy-rich foods, which contain unhealthy fats and free sugars (e.g., soft drinks, convenience foods, fatty and sweet baked goods, and meat products). Additionally, if possible, avoid the consumption of alcohol.

Along with weight loss, it is crucial to maintain the new healthier weight. To achieve this, alongside a healthy diet, physical activity is particularly important.

Find out more here about being overweight and obesity!

Find out more here about physical activity!

Good to know:

A woman measuring 160 centimeters and weighing 70 kilograms needs to lose at least 3.5 to 7 kilograms. This corresponds to 5 to 10 percent of her initial weight.

A balanced diet provides the body with essential energy and nutrients and increases quality of life. Vitamins and minerals help us feel fit and enable many processes in the body to function correctly. For example, secondary plant substances from fruit and vegetables help support the immune system. Fiber helps improve digestion, among other things. Some types of fat (e.g., from oily sea fish or linseed) support the functioning of thought-related processes.

Diet is the basis of the treatment of type 2 diabetes and makes managing the disease easier. Especially in the early stages of the disease, people with diabetes can use dietary measures together with physical activity to help control their blood sugar levels. This can often be an adequate course of treatment without the need for medication.

By eating a balanced and varied diet, people with type 2 diabetes can help reduce the risk of other accompanying disease and complications, including nerve disorderheart attack or diabetic foot syndrome. Elevated blood lipid levels and high blood pressure, which often appear together with type 2 diabetes, also improve with the right diet.

Here you can find out more about the complications of type 2 diabetes!

Based on current knowledge, no definitive form of nutrition or diet can be recommended for people with diabetes. A choice of different diets is possible for both people with and without diabetes.

Specialist diabetes associations currently assume that there is no single dietary pattern that is equally suitable for all diabetes suffers. The diet best suited to diabetes appears to vary from person to person. For this reason, individually tailored nutritional counseling for people with diabetes is recommended. In this context, a nutritional concept based on diabetes therapy, personal preferences, and everyday circumstances can be created that can be implemented in everyday life for each individual.

According to current data, a low-carbohydrate diet is most likely to improve sugar metabolism. A diet with reduced carbohydrate consumption can be implemented using various types of dietary patterns. However, the German Diabetes Association points out that you should not only refer to the proportion of essential nutrients – carbohydratefats and proteins. The composition of the nutrients and the properties of the foods also play a significant role. The fat composition, fiber content, and effects of carbohydrate-containing foods on the blood sugar level should also be taken into consideration for the respective diet.

Special foods for people with diabetes are not necessary. They often contain sugar substitutes, for example, fructose. These substances contain the same energy as normal sugar and therefore provide no benefits. Furthermore, these products can contain high levels of fat and therefore more energy than normal foods. For this reason, since 2012, it has no longer been permitted to sell special foods for people with diabetes in Germany.

Carbohydrates, alongside fat and protein, are crucial energy sources for the human body. All carbohydrates are made up of sugar building blocks: some contain only 1 or 2 sugar building blocks (e.g., glucose or household sugar), whereas others are made up of long chains of sugar building blocks (for example strach). The body transforms the consumed carbohydrates into glucose (1 sugar building block) to generate energy.

Scientists have not yet succeeded in determining the ideal amount of carbohydrates as a proportion of the diet. This applies both to people with and without diabetes. The German Diabetes Association states that between 45 and 60 percent of the overall energy needs can be consumed via carbohydrates. Although many studies consider this recommendation to be too high.

The currently available data indicates that a reduced carbohydrate intake can most likely result in an improvement to the sugar metabolism. Against this backdrop, for certain persons with type 2 diabetes, for example, those unable to achieve their target blood sugar levels, a low-carbohydrate diet may be a suitable option. Depending on the definition, a diet with a moderate reduction in carbohydrates is characterized by a proportion of 26 to 45 percent carbohydrates in the total energy intake.

However, the German Diabetes Association does not recommend specifically restricting the intake of one main nutrient in the diet in the long term. They also stress that the composition of the nutrients, i.e., the properties of the foods, for example, the fatty acid pattern or proportion of fiber, are more important than their intake as an overall percentage.

People with diabetes should eat carbohydrates from vegetables, pulses, fresh fruit, and wholewheat products. Among other things, these products all have high levels of fiber, which cause blood sugar levels to increase more slowly. People with diabetes should eat approx. 40 grams of fiber per day. This corresponds to 5 portions of fruit and vegetables (1 large apple, 1 bowl of raspberries, lettuce, tomatoes, potatoes as a side dish, etc.) and 2 to 3 slices of wholewheat bread.

Good to know:

More important than the quantity are the properties of carbohydrate-rich foods.

On the other hand, people with diabetes should eat less white flour products and free sugars. These types of foods cause a rapid increase in blood sugar levels. Specialist associations recommend no more than 50 grams of free sugars per day. This corresponds to approx. 12 teaspoons per day. Free sugar refers to all sugars added to foods and drinks and sugar naturally contained in honey, syrup, fruit juices, and fruit juice concentrates.

Take note: Processed food often contain a lot of sugar even though it tastes salty.

There are alternatives to conventional sugar for the sweetening of foods. These alternatives can be categorized into two groups:


Sweeteners are produced artificially. They provide no energy and have no effect on blood sugar levels. According to specialist associations, sweeteners can help achieve or maintain a healthy body weight when their use leads to a reduction in the consumption of energy-rich foods with added sugar.

However, care should be taken not to exceed the acceptable daily maximum amount. These amounts are determined by the European Union (EU). All food producers in the EU must adhere to these maximum levels when processing sweeteners in food, meaning these products should be safe. Examples of sweeteners are cyclamate, saccharine, acesulfame K, aspartame, or stevia.

Sugar substitutes

Sugar substitutes are usually of natural origin and have no effect on blood sugar levels. Because the majority of sugar substitutes contain calories, they should not be consumed in large amounts. Consuming large amounts of sugar substitutes can lead to stomach pain or diarrhea. Examples of sugar substitutes are sorbitol, xylitol, isomalt, maltitol, or lactitol.

Take note: However, food packaging declares sugar replacement substances as carbohydrates. People who require Insulin therapy should look closely to see if these are carbohydrates that affect blood sugar levels or not. If the product contains a sugar substitute, then this should be subtracted during the calculation of the insulin dosage.

The glycemic index (GI) illustrates the effect of foods containing carbohydrates on the blood sugar level. It predicts how fast and how much the blood sugar will increase after eating a certain type of food.

The 100% reference value is the blood sugar level after the intake of 50 grams of dextrose. When comparing to other foods, the exact amount of the respective food that also contains 50 grams of carbohydrates is used. For example, that would be 100 grams of lentils or 60 grams of cornflakes. Foods containing carbohydrates that have a high GI (e.g., white bread, cornflakes, or French fries) cause a large and rapid increase in blood sugar levels. In contrast, foods containing carbohydrates that have a low GI (e.g., pulses, vegetables, and wholewheat products) enter the bloodstream more slowly, resulting in a more moderate increase in blood sugar levels.

To estimate the effects of a food containing carbohydrates on the blood sugar level in relation to the amount of carbohydrates consumed, the glycemic load (GL) is also often calculated. GL provides an indication of the blood sugar response to a portion of a food containing carbohydrates. The GL is the product of the GI and the net carbohydrates (in grams) per food portion divided by 100.

Good to know:

Formula to calculate the glycemic load (GL):

GL = GI x consumed net carbohydrates [g]  / 100

For example, a baguette and carrots have a similar GI. With a higher proportion of fiber and the corresponding lower proportion of net carbohydrates, the GL of carrots is significantly lower in comparison to the GL of a baguette.

Foods with large amounts of complex carbohydrates and fiber generally have a low GI. But also the method of preparation can influence the GI. For example, cooked carrots have a higher GI than raw carrots. In addition, the side dishes on a meal can influence how rapidly the carbohydrates are transferred into the bloodstream.

Carbohydrate-rich foods with a low GI are a suitable choice, provided the other ingredients of the respective food are also beneficial to health.

Taking smaller steps in the beginning is often easier than making a radical change. New steps can be gradually introduced until the desired objective is achieved. The objective of nutritional therapy for diabetes mellitus is an individually tailored, balance, wholefood diet that meets individual nutrient requirements and leads to an improved metabolic status.

Goals often vary among affected individuals. Any change to a diet should be discussed and coordinated with the treating physician, also in the context of potentially preexisting complications.

All people with diabetes should also take part in training programs. Nutritional counseling dealing with individual questions and needs should be a component of the training and medical care. The treating physician can help find a suitable program.


Good to know:

Nutritional counseling is part of every training program for people with diabetes.


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As of: 25.01.2021