Diabetes mellitus is a complicated disease that occurs when the body’s ability to produce or respond to insulin is impaired (1). There are several kinds of diabetes, all of which result in uncontrolled blood glucose levels. Left untreated, diabetes can negatively affect nearly every system in your body (2). Blindness, neurological damage, seizures, and kidney failure can all occur as the result of long- or short-term uncontrolled diabetes.

Diabetes can be caused by any combination of genetic factors, diet, lifestyle, medications, or illness. Regardless of the cause, however, one thing is certain: the incidence of diabetes is increasing at a dangerous rate. The most common form of diabetes, type 2 diabetes, is almost always linked to unhealthy body weight and poor diet.

More than two-thirds of American adults are now overweight or obese – a number that has more than tripled since 1960 (3). Not surprisingly, approximately 90% of type 2 diabetics are overweight or obese (4). Excess body weight is by far the strongest predictor for whether or not someone will develop diabetes, but it is not the only factor.

What causes diabetes? 

The core of any diabetes diagnosis is chronic hyperglycemia, which means that blood glucose levels are consistently elevated (5). In a healthy individual, blood sugar (glucose) levels rise after the consumption of any form of carbohydrate. The body uses glucose for energy, but cannot make use of it without insulin to draw glucose into cells. Insulin is a hormone released by beta cells in the pancreas. With diabetes, the body either does not produce enough insulin, is unable to utilize the insulin it does product, or both.

Without the ability to make use of glucose, you’ll likely start experiencing side effects. This can range from fatigue, hunger, and difficulty concentrating to excess urination and blurry vision (6). The only way to know if you have diabetes is through a blood test; we’ll discuss diagnosis and treatment is just a bit.

What Are The Different Types of Diabetes?

Type 1 Diabetes

Often referred to as insulin-dependent diabetes, Type 1 diabetes is an autoimmune disorder where the body attacks the pancreas (7). It used to be called juvenile diabetes as it is most often diagnosed in childhood. The beta cells that store and release insulin are attacked and destroyed by the body (8). As a result, the affected individual cannot lower their own blood glucose levels.

Prior to the discovery and development of injectable insulin in 1921, the life expectancy of a type 1 diabetic was measured in months (9). Death most often occurred as a result of diabetic ketoacidosis, a condition that results from the body breaking down fat for energy. The process of breaking down fat releases ketones. At high enough levels, ketones cause the blood to turn acidic and affect all body systems (10). Thankfully, with the advancements made by the early 1980s in insulin and diabetic management tools, diabetic ketoacidosis is now relatively uncommon.

Type 2 Diabetes

Approximately 95% of all diabetes cases are type 2 diabetes. This is a metabolic disorder in which the body is unable to produce enough insulin or unable to efficiently use the insulin it does produce (11). The symptoms of type 2 diabetes are usually mild, and it is estimated that approximately three percent of American adults have type 2 diabetes and don’t know it (12).

As previously mentioned, approximately 90% of type 2 diabetics are overweight or obese. The modern standard American diet is now recognized as a major contributing factor to type 2 diabetes, along with obesity and a sedentary lifestyle. High sugar, high cholesterol, and high saturated fat foods contribute directly to both weight gain and insulin resistance. Left unchecked, this is the perfect storm to induce full-blown type 2 diabetes.

The good news is that type 2 diabetes can often be managed though dietary and lifestyle changes (13). Adopting a low-carbohydrate, high fiber diet prevents blood sugar levels from rising in the first place. Regular exercise improves insulin response and lowers blood glucose levels, since muscles can use glucose for energy without insulin. By combining diet and exercise, you’ll reduce excess bodyweight and increase lean muscle mass.

Unlike type 1 diabetes, type 2 diabetes can be cured through consistent diet and exercise in the majority of cases. There are some medications that can be used to help the body better respond to insulin, but they are not as effective as a low-carb diet and exercise. Insulin is rarely used as a treatment, and usually only for someone who has had type 2 diabetes for a long time.

Gestational Diabetes

Pregnancy messes with a woman’s body a number of ways, one of which can be the development of type 2 diabetes due to hormonal changes (14). Somewhere between 2% and 5% of all pregnancies result in gestational diabetes (GD), which often resolves itself after the baby is born. More often than not, GD will develop in the later stages of pregnancy. However, women who are overweight or have a history of insulin resistance are at a higher risk for GD and may develop it in the first trimester.

GD presents a unique set of risks to both mother and fetus. Both are at risk for all of the same health complications associated with hyperglycemia. However, the risks to the unborn child are greater since their body is still developing. The most common side effects are large birthweight, respiratory problems after birth, and a significantly higher risk of developing diabetes and obesity. The mother may need a cesarean section due to the baby’s size, and may suffer damage to a number of her body’s systems. She will also be at a higher risk of developing type 2 diabetes later in life.

Treatment of gestational diabetes is similar to the treatment pf type 2 diabetes. Diet and exercise are the best and most effective options, but diabetic medications can be utilized if necessary. Most women will have to monitor their blood sugar levels throughout the day and will require diabetic testing in the months following delivery.

Other Forms of Diabetes

Type 1, type 2, and gestational diabetes account for over 95% of all diabetes cases. There are, however, over 10 different kinds of diabetes that are differentiated by their causes, symptoms, or age of development. Almost all are a subset of type 1 or type 2 diabetes.

Diabetes LADA, or Type 1.5 Diabetes

LADA stands for Latent Autoimmune Diabetes of Adulthood. In a nutshell, it is type 1 diabetes that develops later in life as opposed to childhood (15). LADA is often misdiagnosed as type 2 diabetes because its development is gradual and may not immediately require insulin. For a diagnosis of LADA, your doctor will test you for GAD (glutamic acid decarboxylase) antibodies. GAD antibodies point to destruction of pancreatic cells, and are present in all forms of type 1 diabetes (16).

Diabetes MODY

Mature Onset Diabetes of the Young (MODY) is type 2 diabetes that occurs in young, healthy adults under the age of 25 (17). It has a high genetic correlation as it often runs in families: children born to a MODY patient have a 50% chance of inheriting it. Unlike other forms of type 2 diabetes, MODY is not associated with excess bodyweight. There are six different forms of MODY known at this point.

Brittle Diabetes, or Labile Diabetes

A brittle diabetic is an individual with type 1 diabetes that is hard or impossible to control, even with constant monitoring and insulin (18). In a normal type 1 diabetic, blood glucose levels are measured before and/or after a meal and an appropriate amount of insulin is administered to prevent hyperglycemia. Blood glucose then levels return to normal levels until after the next meal.

Brittle diabetics do not respond to insulin the same way every time it is administered. They may experience delayed absorption, leading to hyperglycemia. They may respond too strongly to the insulin, leading to hypoglycemia (low blood sugar). Sometimes, the same person can experience hyperglycemia and hypoglycemia in the same day. As a result, brittle diabetics tend to require emergency intervention and hospitalization more often than other diabetics.

Frequent glucose testing, careful meal planning, and the use of an insulin pump are often required in an attempt to manage brittle diabetes. If an underlying cause can be identified and corrected, brittle diabetics can resolve into normal type 1 diabetes. Unfortunately, this is not always possible.

Prediabetes or Insulin Resistance

Insulin resistance is a precursor to type 2 diabetes (19). A prediabetic individual has higher-than-normal blood glucose levels, but not quite high enough to be classified as type 2 diabetes. Left untreated, insulin resistance can cause the same health problems as type 2 diabetes – even if it does not progress to full blown diabetes. The treatment of prediabetes is the same as type 2 diabetes: a healthy, high-fiber, low-carb diet and routine physical activity.

Double Diabetes

An individual with double diabetes is a type 1 diabetic that, over time, develops insulin resistance (a hallmark of type 2 diabetes) (20). It is most often the result of being overweight or obese and leading a sedentary lifestyle, like most other type 2 diabetics. Double diabetics can often treat or cure their type 2 diabetes through diet and exercise, but they will always have type 1 diabetes.

Secondary Diabetes

Secondary diabetes is the development of either type 1 or type 2 diabetes that results from a separate medical condition or medication (21). These conditions either cause insulin resistance, leading to type 2 diabetes, or impair/destroy the pancreas and result in type 1 diabetes. The following conditions are all associated with an increased risk of secondary diabetes:

–       Cushing’s syndrome

–       Hemochromatosis

–       Chronic Pancreatitis

–       Polycystic Ovary Syndrome (PCOS)

–       Pancreatectomy

–       Pancreatic cancer

–       Glucagonoma

–       Cystic Fibrosis

–       Obstructive Sleep Apnea

Drug-Induced Diabetes

Certain medications prescribed for separate conditions can cause an increase in blood glucose levels, resulting in this form of secondary diabetes (22). Discontinuation of the medication may or may not resolve the diabetes, but for many the medication is required to manage a more severe condition. Drug-induced diabetes may be caused by any of the following medications (list is not all inclusive):

–       Corticosteroids

–       Statin medications

–       Thiazide Diuretics

–       Antipsychotics

–       Beta-blockers

Diabetes Insipidus

Diabetes insipidus is a particularly rare disorder characterized by excessive thirst and urination (polyuria) (23). It has nothing to do with a person’s blood sugar level, but the condition shares many of the same signs and symptoms of diabetes (24). The word insipidus refers to the insipid nature of the affected individual’s urine: very dilute and odorless.

Remember that the above list is not all inclusive. There are several forms of diabetes that are extremely rare and usually associated with a genetic disorder or a severe type of secondary diabetes.

How do you know you have diabetes? 

Symptoms of diabetes may mirror other conditions, so it is important to see your doctor if you suspect you have diabetes.

Symptoms of Type 1 diabetes:

–       Fatigue

–       Constant, excessive urination

–       Unexplained weight loss

–       Excessive thirst

–       Unusual itchiness in the genital region

Symptoms of Type 2 diabetes:

–       Excessive thirst

–       Constant, excessive urination

–       Increased appetite

–       Extreme fatigue

–       Loss of muscle mass

Symptoms of type 1 diabetes usually appear in childhood and develop rapidly. Type 2 diabetes, on the other hand, tends to develop more slowly and may even go unnoticed. A diagnosis of diabetes can only be made through blood testing. Your doctor will test your fasting blood glucose levels as well as your Hemoglobin AIC (HgbA1C) (25).

Blood glucose levels are usually done while fasting, and give an idea of how well your body response to insulin.

–       Normal fasting blood glucose: 70-100 mg/dL

–       Normal non-fasting glucose: <125 mg/dL

–       Prediabetes/Insulin Resistance: 100-125 mg/dL

–       Diabetes: <125 mg/dL   Your doctor may also ask you to perform an oral glucose tolerance test (OGTT) following a fasting blood glucose test. You will be given a sweet drink with a specific amount of sugar in it and your blood will be tested 2 hours later. These results are an indicator of how well your body processes glucose. An OGTT test is required to make a diagnosis of gestational diabetes. –       Normal: >140 mg/dL

–       Prediabetes: 140-199 mg/dL

–       Diabetes: 200 mg/dL

The HgbA1c test is used to measure an individual’s insulin response and blood glucose control for the last two to three month’s time. The test is not considered an accurate measurement if it is tested more than once every 12 weeks. For both type 1 and type 2 diabetics, HgbA1c testing is recommended every three months.

–       Normal Range: 4.5-5.7%

–       Insulin Resistance/Pre-diabetes: 5.7-6.0%

–       Diabetes: >6.0%

There are risk factors for diabetes that make you more susceptible to developing diabetes. They include, but are not limited to:

–       Excess bodyweight or body fat

o   Being overweight or obese is the number one risk factor for developing insulin resistance or type 2 diabetes. Likewise, if you are within a ‘healthy’ weight range but have a high body fat percentage (a.k.a. skinny fat), you are at just as much of an increased risk as an overweight individual

–       Age

o   Children are more likely to develop type 1 diabetes than type 2. Anyone over the age of 45 is at a higher risk of developing type 2 diabetes

–       Race

o   Caucasians are more likely to develop type 1 diabetes, whereas individuals of Hispanic, Native American, Asians, Pacific Islander, and African descent are more susceptible to type 2 diabetes

–       Location

o   Though the reason is unknown, those who live further North in colder climates are at an increased risk of developing type 1 diabetes

–       Family history

o   Both type 1 and type 2 diabetes have genetic components. If a parent or sibling has diabetes, you are at a higher risk of developing the same type.

–       Gestational diabetes

o   Both mother and child are at a higher risk of type two diabetes if the mother was diagnosed with gestational diabetes

–       Sedentary lifestyle

o   The more physically active you are, the less likely you are to develop insulin resistance or type two diabetes – and vice versa. Physical activity also helps control body weight, another risk factor

–       Waist size

o   Though it is important to take height into account, there is a correlation between type 2 diabetes and men with waistlines greater than 40 inches or women with waistlines larger than 35 inches

–       Diet

o   As mentioned before, a high sugar, high cholesterol, high saturated fat diet is one of the biggest contributors to insulin resistance. This correlation specifically includes processed meats, red meat, sodas and any other sugary or sweetened beverages – including fruit juice

What Are The Long-term Dangers Associated With High Blood Sugar Levels?

First and foremost, hyperglycemia contributes to chronic inflammation in the body. Ironically, chronic inflammation can also cause insulin resistance. This is a vicious cycle that can do an incredible amount of damage if left unchecked.

Inflammation is part of the body’s immune response to fight off infection, chemicals, heal injuries, ect… With diabetes, inflammation is extremely hard to control and leads to a number of complications (26). Excess blood sugar levels cause inflammation throughout your cardiovascular system, contributing to heart disease and vascular damage. With an undue level of inflammatory response literally coursing through your veins, organs and nerves often become the next victims.

Uncontrolled hyperglycemia and inflammation leads to the following complications (27):

–       Diabetic neuropathy – nerve damage and pain as the result of diabetes

–       Diabetic retinopathy – damage to the blood vessels in the eyes – and blindness

–       Poor blood flow to extremities

o   This can result in infections and wounds that won’t heal properly, often resulting in amputation

–       Diabetic nephropathy – kidney damage

–       Gum infections

–       Tooth infections

–       Skin infections

–       Cataracts

–       Dehydration

–       Cardiovascular disease

–       Diabetic ketoacidosis

–       Diabetic Coma

–       Death (usually as the result of ketoacidosis leading to coma)

You can fight inflammation first and foremost by sticking to an anti-inflammatory low-carbohydrate diet. Regular exercise is also important to reduce inflammation and maintain a healthy weight. It is important to keep note of any foods or activities that you feel cause increased inflammation on your body as well.


A diagnosis of diabetes or prediabetes can be scary, but don’t let the fear paralyze you to the point of inaction. Take control of your blood sugar – and your health – by making the appropriate changes to you diet and lifestyle.

Start by eliminating added sugars, processed foods, and unnecessary calories. Make it fun by trying new recipes and preparing your own food (instead of relying on the microwave). Make sure your meals are colorful and filling, with at least one serving of whole fruit or vegetables at every meal.

If you’re not already, begin an exercise routine focused on cardiovascular fitness. This can be as simple as walking for 30 minutes a day. As you get more in shape, incorporate strength training. Consider a group fitness class. You’ll be amazed how much better you feel after a few weeks of regular activity!

Bottom line: you only have one body, and you need to take care of it. Even if it fights you tooth and nail. Listen to your doctor. Remember that you have diabetes – diabetes does NOT have you.