FREE shipping on every order!

What Causes Type 2 Diabetes: All You Need to Know

Friderike Gerlinger

We Hope You Enjoy Reading This Post

To discover more from our experts about any symptoms you’re experiencing, click here


What causes type 2 diabetes? These days, more and more people are affected by this type of diabetes. Although it develops gradually – and sometimes without any symptoms, it can trigger serious secondary diseases. But with the right diet and exercise, type 2 diabetes can be well prevented and treated.

It may come as no surprise to you that diabetes is one of the most widespread diseases – especially in the Western world: In the United States, just over 30 million people have type 2 diabetes – that’s around nine percent of the population.[19] In addition, there are an estimated seven million people who are not yet aware they have diabetes.[20]

What causes type 2 diabetes? Type 2 diabetes is considered a privileged disease. This is because high-fat foods, obesity, a lack of exercise, and an increasing life expectancy are the main reasons why diabetes is becoming more widespread.[3] However, this also means that, in most cases, you can do a lot yourself to prevent type 2 diabetes or to reduce the severity of the disease.

What is type 2 diabetes and how does it develop? Who is particularly at risk and what are the signs of type 2 diabetes? How is the disease diagnosed and is there any treatment available? Do type 2 diabetics need to follow a strict diet? Read on to find out.

What Is Type 2 Diabetes?

Diabetes mellitus, also known as diabetes, is a metabolic disease whereby sufferers have too much sugar in their blood. Experts refer to this as chronic hyperglycemia (high blood sugar).

Experts are concerned about the rising numbers of type 2 diabetes worldwide. Diabetes increases the risk of various secondary diseases, including cardiovascular disease, kidney damage, and visual and nervous symstem disorders.

Type 2 diabetes costs the health care system a lot of money: Did you know that, worldwide, ten percent of health care funds are already spent on diabetes patients each year. That’s around 760 billion US dollars.[4]

How Does Type 2 Diabetes Affect the Body?

People with diabetes have problems with the hormone insulin. In the case of type 2 diabetes, this means that the pancreas produces insulin that can no longer be absorbed as well by the body’s cells.[5]

When insulin no longer works on the body’s cells, sugar builds up in the blood. Long-term high blood sugar can cause damage, so the body tries to get rid of the excess sugar. Type 2 diabetics then excrete sugar through their urine, for example, and therefore often feel the urge to urinate more frequently – a typical sign of of diabetes.[6]

Type 1 diabetes is an autoimmune disease, where the body destroys its own pancreatic cells that are responsible for insulin production. As a result, those affected have little or no insulin available. You can read more about this in our article on type 1 diabetes.

cerascreen Blood Sugar Test

What Does Insulin Do in Our Body?

Insulin is a vital hormone in the human body. It is produced in the pancreas. After a meal, small sugar components enter our blood; the pancreas reacts to this and releases insulin into the blood.

Insulin transports the sugar from the blood into our body cells. The cells, in turn, use sugar as their main source of energy, enabling vital bodily functions such as movement, breathing, and brain and cardiac activity.[7]

What Causes Type 2 Diabetes?

Type 2 diabetes develops over a long period of time and usually without the person affected noticing any of the typical signs of type 2 diabetes.

With type 2 diabetes, insulin no longer works properly in the body’s cells, which means that they become less sensitive to insulin. As a result, sugar cannot be absorbed into the cells and remains in the blood. Experts call this disorder insulin resistance.”

To lower blood sugar levels, the pancreas initially produces more and more insulin. At some point, the effort becomes too great, and not enough insulin can be produced. This is known as relative insulin deficiency, meaning the pancreas produces insulin, but not enough for the body’s insulin-resistant cells. They are therefore still unable to absorb the sugar from the blood.[7]

This process is gradual: A permanently high blood sugar level does not initially cause any pain or severe symptoms in those affected and is often only recognized when secondary diseases, such as visual impairment, first emerge. Experts estimate that type 2 diabetes is usually diagnosed around ten years too late.[6]

How Are Stress and Blood Sugar Linked in Type 2 Diabetes?

When you are under stress, your body gets ready to provide you with a lot of energy. To do this, it raises your blood sugar levels, so that important organs and muscles are supplied with glucose. Stressful situations can therefore promote high blood sugar in people with type 2 diabetes – in some cases, so much so that the dose of medication or insulin needs to be adjusted.

Can Stress Contribute to Type 2 Diabetes? 

Scientists are discussing whether chronic stress could trigger the development of type 2 diabetes in the first place. Apparently, chronic stress also drives up blood sugar levels over the long term and can also increase inflammation levels in the body. For people who already have a high risk of diabetes, this may be a decisive factor in the onset of the disease.

Study analyses suggest that general emotional stress, depression, anxiety, sleep problems, and chronic burnout can increase the risk of diabetes. However, researchers emphasize that long-term studies are still needed to determine the exact link between these factors and type 2 diabetes.[16–18]

So, take stress in everyday life seriously, especially as a diabetic! Chronic stress is not something that should be part of your professional or private life, and it poses a serious threat to your health.

In our Health Portal, you will find tips on how to identify signs of stress, develop strategies for coping with stress, and train your emotional resilience through your way of thinking.

Who Is Most at Risk of Type 2 Diabetes?

Type 2 diabetes is related to an unhealthy lifestyle in most of those affected and often first appears after the age of 40. Recently, however, more and more younger people, children, and adolescents are also affected. Many of those affected suffer from obesity, which is also becoming more common at a younger age.

Smoking, a lack of exercise, and an unhealthy diet increase the risk of developing this form of diabetes. Other factors include:[7]

  • Frequent family history of type 2 diabetes
  • Obesity, high blood pressure, and elevated cholesterol levels
  • Diabetes during pregnancy
  • Medications that affect sugar metabolism (for example, cortisone)
  • Other hormonal disorders (for example, polycystic ovary syndrome, PCOS)

If you’re concerned about your cholesterol levels, you can always opt to take a cholesterol test with your doctor or take one within the comfort of your own home. Regulating and optimizing your cholesterol levels can help you reduce the likelihood of obesity and type 2 diabetes.

    What Are Typical Type 2 Diabetes Symptoms?

    Type 2 diabetes develops gradually, so that the disease often remains undetected for years. At some point, however, the lack of sugar in the cells becomes noticeable, because the body lacks the necessary energy in various places.

    Typical signs of type 2 diabetes include:[8]

    • A lack of drive, depressive moods, fatigue
    • A lack of concentration, forgetfulness
    • Itchy, dry skin
    • Poorly healing wounds
    • A stronger feeling of thirst, greater urge to urinate

      How Is Type 2 Diabetes Diagnosed?

      In people with type 2 diabetes, blood sugar levels (also known as blood glucose levels) are elevated over the long term.

      The doctor usually takes a blood sample to detect diabetes. There are four different blood tests available to measure blood glucose levels in your body:[11]

      • HbA1c value (long-term blood glucose value)
      • Fasting blood glucose value
      • Two-hour blood glucose value after an oral glucose tolerance test with 75 grams of glucose (OGTT)
      • Casual blood glucose

        What Is an HbA1c Value?

        The long-term blood glucose value HbA1c provides you with information about your average blood glucose values over the last 2 to 3 months. It measures what percentage of hemoglobin is saccharified. You do not need to fast for the long-term blood glucose (HbA1c) test.

        Type 2 diabetes is present if your HbA1c value is 6.5 percent (48 mmol/mol) or higher, but the disease can definitively be ruled out if your HbA1c value is less than 5.7 percent (39 mmol/mol).

        If your HbA1c value lies between this range, you could be at risk of prediabetes, which is the precursor of type 2 diabetes. In such cases, doctors usually carry out further tests to measure your fasting blood glucose value as well as the OGTT two-hour blood glucose value.[11]

        In most cases, prediabetes can be treated with a change in diet and more exercise; these proactive lifestyle changes can help prevent the development of type 2 diabetes.

        What Does a Fasting Blood Glucose Level Tell Me?

        The fasting blood glucose value is measured in the morning after you have fasted, meaning you have not eaten anything from eight to twelve hours beforehand. The doctor will draw your blood and determine your fasting blood glucose – for people with type 2 diabetes, this value is 126 mg/dl (7.0 mmol/l) or higher.

        If your value is between 100 mg/dl (5.6 mmol/l) and 125 mg/dl (6.9 mmol/l), you may have prediabetes. To clarify this, doctors usually perform an oral glucose tolerance test.[11]

        What Is an Oral Glucose Tolerance Test?

        This blood test shows how well the sugar from food can be absorbed into your body’s cells. In people with type 2 diabetes, insulin no longer works properly in their body’s cells, meaning blood sugar usually rises higher and for longer than in people without diabetes.

        This is how the oral glucose tolerance test is performed:[11]

        • You must not eat or smoke eight to twelve hours beforehand. You must also avoid sugary drinks and alcohol.
        • At least three days before the test, you should eat a diet rich in carbohydrates (150 to 250 grams of carbohydrates per day), so that the blood values are not falsified.
        • At the start of the test (time 0), you will drink a preprepared glucose solution containing 75 grams of glucose (dextrose).
        • Your blood will be drawn twice: once at the start and the second time after two hours. Doctors therefore measure your blood glucose levels twice.

          If the OGTT-2-h value in the blood is 200 mg/dl (11.1mmol/l) or more, you are able to diagnose type 2 diabetes.

          What Does Casual Blood Sugar Mean?

          If you already have signs of type 2 diabetes, such as an increased urge to urinate or a stronger feeling of thirst and weakness, a casual blood glucose test can also be a way of detecting type 2 diabetes.

          The doctor will draw your blood, but you do not have to fast for this test. If blood glucose values of 200 mg/dl (11.1 mmol/l) or more are found in the laboratory, this indicates diabetes.

          However, the diagnosis should then be additionally checked by determining the fasting blood glucose or with the aid of an OGTT.[11]

          How Is Type 2 Diabetes Usually Diagnosed?

          Doctors can diagnose type 2 diabetes with the following blood glucose levels:[11]


          Type 2 Diabetes

          HbA1c value

          from 6.5% (from 48 mmol/mol)

          Fasting blood glucose level

          from 126 mg/dl (from 7.0 mmol/l)

          Oral glucose tolerance test

          from 200 mg/dl (from 11.1mmol/l)

          Casual blood sugar

          from 200 mg/dl (from 11.1 mmol/l)


            What Are Secondary Long-Term Complications of Diabetes?

            If type 2 diabetes is not treated – that is, if blood glucose levels are far too high for a long time – the nerves and blood vessels in the body may become damaged.

            This can lead to high blood pressure, a heart attack, or a stroke – and also kidney or eye damage and diabetic foot syndrome.[8]

            What is diabetic foot syndrome? Many diabetics have foot sores because years of high blood glucose levels damage nerves and blood flow. Therefore, many people with type 2 diabetes suffer more from injuries to their feet, and the wounds do not heal well on their own.[9]

            Does Type 2 Diabetes Qualify for Disability?

            For many type 2 diabetics, living with diabetes is a great challenge, and some people are severely restricted in their daily lives. According to the federal law, diabetes, which can be a so-called invisible disability, is classified as a disability because it significantly limits the function of the endocrine system. Even if a person is healthy and can manage their diabetes well, diabetes is still considered a disability.[21]

            How Is Type 2 Diabetes Treated?

            The good news for those affected is that if you have type 2 diabetes, you usually don't need to inject yourself with insulin right away. Often, switching to a healthier lifestyle is enough. If you lose weight by changing your diet and exercising more, you can often lower blood glucose levels well.

            If this basic treatment is not enough, doctors can prescribe tablets that improve the sensitivity of the body’s cells to insulin. The longer the disease lasts, the more likely it is that insulin deficiency will occur. In this case, those affected must also inject themselves with insulin.[6]

            People with type 2 diabetes have to change their lifestyle, and this is not always easy in practice. Ask your doctor about diabetes courses as part of a disease management program. These are specifically geared to managing the disease as part of your everyday life.[12]

            Type 2 Diabetes Diet: What Can I Eat?

            With type 2 diabetes, you don’t need to follow a special diet, but you do need to keep your blood glucose levels under control. This means that you should change and design your meals and snacks so that they are healthy and fit well into your everyday life.

            Everyone has different tastes and dietary requirements that should be taken into account. This is why it’s best to get help from a qualified or certified nutritionist – especially if you need to inject insulin and calculate your carbohydrate intake.

            Here are some tips on how to live with type 2 diabetes; these will keep your blood sugar levels under control:[13]

            • Drink at least 1.5 liters of water or unsweetened fruit/herbal teas per day
            • Eat foods high in fiber (vegetables, legumes, fresh fruits, whole grains)
            • Opt for vegetable oils, nuts, and seeds
            • Choose lean meats, fish, and low-fat dairy products
            • Eat sugar and candy in small quantities

              The following foods will cause your blood sugar level to shoot up and should therefore be avoided:

              • Ready-made products, highly processed foods, fast food, and white-flour products
              • Large amounts of sugar, fructose, and sugar alcohols (e.g. sorbitol, xylitol), which are also found in drinks such as juices, smoothies, and lemonades
              • Alcohol and cigarettes
              • Large amounts of fatty meat, fatty pork, fatty cheese, fatty bakery products, and cream
              • Large quantities of snacks and candy (chocolate, potato chips, etc.)

                What Is the Best Fruit for Diabetics to Eat?

                Fresh fruit contains a lot of fiber, vitamins, and minerals and is therefore also recommended for diabetics. Two handfuls of fresh fruit a day are ideal!

                However, fruit also contains fructose. For people with diabetes, it can therefore make sense to eat only one portion of fruit at once or to combine the fruit portion in a meal, for example with muesli or yogurt. Both of these tips ensure that blood sugar levels do not rise too quickly.

                Here are some examples of fruits with low, medium and high fructose content [14]:

                Low Sugar Content

                Medium Sugar Content

                High Sugar Content








                Apricot, peach





                Apple, pear




                Did you know that dried fruit contains much more sugar than fresh fruit? Please eat dried fruit in moderation.

                Is Bread Bad for Diabetics?

                Bread contains a lot of carbohydrates. That’s why it's especially important for people with type 2 diabetes to choose the right bread.

                White-flour products such as toast and white bread are full of simple carbohydrates that the body can break down quickly. They therefore cause blood sugar levels to skyrocket. It is therefore better to avoid white bread!

                Choose whole-grain, nutty, or protein bread. Protein, fiber (in nut and whole-grain bread), and few carbohydrates ensure that your blood sugar level rises slowly. They also keep you full for longer and provide more nutrients than white bread.[15]

                Breakfast tip: Do you enjoy waking up to a bowl of muesli in the morning? Then it’s best to mix your own muesli using cornflakes, nuts, and fresh fruit. The ready-made versions from your local grocery store often contain added sugar and dried fruit – both of which cause blood sugar levels to rise faster!

                How Can I Best Prevent Type 2 Diabetes? 

                1. Develop a healthy eating and exercise plan
                2. Test your blood sugar levels, and keep a record of the results
                3. Recognize the symptoms of high or low blood sugar and how to act
                4. Monitor your feet, skin, and eyes to catch signs early
                5. Manage stress levels through resilience exercises

                What Is Type 2 Diabetes – at a Glance

                What Is Type 2 Diabetes?

                Type 2 diabetes is a metabolic disease whereby those affected have too much sugar in their blood. This is known as chronic hyperglycemia (high blood sugar).

                People with type 2 diabetes have problems with the hormone insulin, which is no longer absorbed as well by the body’s cells; this is known as insulin resistance. This means that sugar builds up in the blood.

                To lower blood sugar levels, the pancreas initially produces more and more insulin. At some point, insulin production decreases, and not enough insulin can be produced. This is known as a relative insulin deficiency.

                What Are Typical Type 2 Diabetes Symptoms?

                Type 2 diabetes develops gradually and initially without symptoms, meaning that the disease often remains undetected for years.

                Later, typical symptoms include fatigue and poor concentration, poor wound healing, dry skin, a strong feeling of thirst, and an increased urge to urinate.

                How Is Type 2 Diabetes Diagnosed?

                There are four different blood tests that doctors can use to determine blood glucose levels. These include the HbA1c test, the fasting blood glucose value, the oral glucose tolerance test, and the occasional blood glucose test.

                What Should My Diet Be Like with Type 2 Diabetes?

                No special diet is recommended for type 2 diabetics. However, those affected should keep blood glucose levels under control with a healthy and balanced diet. This reduces the risk of secondary health conditions.

                Experts recommend a high-fiber diet with plenty of vegetables, whole grains, and legumes. Lean meats, fish, and low-fat dairy products are also ideal for diabetics. You should also opt for vegetable oils.

                Eat whole-grain, nutty, or protein bread and two handfuls of fresh fruit a day – preferably combined with a source of protein.

                Avoid smoking and alcohol, sweetened beverages, ready-made foods, and fast food. Limit sugar and candy on a daily basis.


                [1] Deutsche Diabetes Gesellschaft (DDG) und diabetesDE – Deutsche Diabetes-Hilfe, Deutscher Gesundheitsbericht Diabetes 2021 - Die Bestandsaufnahme, Verlag Kirchheim + Co GmbH, Nov. 14, 2020, available at, accessed on April 13, 2021.

                [2] Rommelfanger J., Brinks R. Diabetes-Uhr: Anzahl der Menschen mit Typ-2-Diabetes steigt bis 2040 auf bis zu 12 Millionen, Deutsches Diabetes-Zentrum (DDZ), available at, accessed on April 13, 2021.

                [3] World Health Organization (WHO), Diabetes, June 8, 2020, available at, accessed on November 18, 2020.

                [4] International Diabetes Federation (IDF), Key Figures Diabetes, IDF Diabetes Atlas 9th edition 2019, available at, accessed on April 13, 2021.

                [5] Was ist Diabetes mellitus? Deutsche Diabetes-Hilfe - Menschen mit Diabetes, available at, accessed on April 15, 2021.

                [6] Typ-2-Diabetes, Deutsche Diabetes-Hilfe - Menschen mit Diabetes, available at, accessed on April 15, 2021.

                [7] Sarabhai T. Wie entsteht Diabetes Typ 2? diabinfo - Das Diabetesinformationsportal, available at, accessed on April 15, 2021.

                [8] Bódis K. Welche Symptome können auf Diabetes hindeuten? diabinfo - Das Diabetesinformationsportal, available at, accessed on April 15, 2021.

                [9] Bönhof G. Diabetischer Fuß” diabinfo - Das Diabetesinformationsportal, April 23, 2020, available at, accessed on April 15, 2021.

                [10] Techniker Krankenkasse, Schwerbehindertenausweis - peinlich oder sinnvoll? Die Techniker, March 12, 2020, available at, accessed on April 15, 2021.

                [11] Karusheva Y. Die Diagnose von Diabetes Typ 2 diabinfo - Das Diabetesinformationsportal, December 4, 2019, available at, accessed on April 19, 2021.

                [12] Schmid S. Schulung bei Diabetes Typ 2” diabinfo - Das Diabetesinformationsportal, November 13, 2019, available at, accessed on April 20, 2021.

                [13] Landgraf R. et al, DDG-Praxisempfehlung: Therapie des Typ-2-Diabetes, vol. 15. Diabetologie und Stoffwechsel - Supplement. Thieme, 2020.

                [14] Laupert-Deick C. DGE-MedienService Obst, Deutsche Gesellschaft für Ernährung e. V. (DGE), 2018, available at, accessed on April 20, 2021.

                [15] Die Ernährungs-Pyramide, diabetesDE - Deutsche Diabetes-Hilfe, November 29, 2017, available at, accessed on April 20, 2021.

                [16] Melamed S., Shirom A., Toker S., Shapira I. Burnout and risk of type 2 diabetes: a prospective study of apparently healthy employed persons, Psychosom Med, vol. 68(6), pp. 863–869, December 2006, doi: 10.1097/01.psy.0000242860.24009.f0.

                [17] Murdock K. W., LeRoy A. S., Lacourt T. E., Duke D. C., Heijnen C. J.,  Fagundes C. P. Executive functioning and diabetes: The role of anxious arousal and inflammation, Psychoneuroendocrinology, vol. 71, pp. 102–109, September 2016, doi: 10.1016/j.psyneuen.2016.05.006.

                [18] Pouwer F., Kupper N., Adriaanse M. C. Does Emotional Stress Cause Type 2 Diabetes Mellitus? A Review from the European Depression in Diabetes (EDID) Research Consortium, Discovery Medicine, vol. 9, no. 45, pp. 112–118, February 2010.

                [19] Type 2 Diabetes, Centers for Disease Control and Prevention, available at, accessed on December 2, 2021.

                [20] National Diabetes Statistics Report 2020: Estimates of Diabetes and Its Burden in the United States,” Centers for Disease Control and Prevention, available at, accessed on December 2, 2021.

                [21] Is Diabetes a Disability? American Diabetes Association, available at, accessed on December 2, 2021.

                Want to Take Control of Your Health?

                We believe you should be able to keep track of your health on your own. That’s why we’ve developed the cerascreen health test kits that you can easily and quickly use within the convenience of your home!
                Our health tests

                Who We Are

                We want to help our customers live a healthier life. To do this, we work with scientists and doctors to develop tests that help you understand your symptoms.
                Learn more

                Free Health Insights

                Subscribe to our newsletter and get information on current health topics, nutrition, and trends. We’ll also give you personal product recommendations and keep you up to date on promotions, discounts, and prize draws. Oh, and don’t forget: We’ll gift you a $5 discount on your first order after you’ve signed up.
                Sign up