Reviewed by Sheri Vettel, MPH RD LDN, IIN Content Writer

What causes diabetes?

Diabetes is a disease that occurs when your body is unable to produce, or has difficulty producing, the insulin it needs to manage blood sugar levels. Insulin is a hormone secreted by the pancreas that has the important job of moving glucose out of your blood and into your cells. The cells either use the glucose as energy, or store it in your muscles and liver to use at a later time. When insulin can’t perform the way the body needs it to, this entire system is disrupted and a person can experience extremely high or low blood sugar, impacting almost every area of the body.

Healthy blood sugar levels rest between 70 and 99 mg/dL, and someone with diabetes can experience highs of 200 mg/dL or more, and lows less than 70 mg/dL, if they are not carefully monitoring their insulin and glucose. Regulating blood glucose levels require balance and daily management, from planning out meals, practicing regular physical activity, and calculating the amount of insulin that one might need to balance highs and lows throughout the day (if necessary). Even high levels of stress can cause blood sugar to rise, so it takes a great deal of perseverance to stay healthy and on track each day.

Three main types of diabetes:

Type 1 diabetes – This is an autoimmune disease where the immune system attacks and destroys the cells in the pancreas that make insulin. This condition is unpreventable and generally diagnosed early in life.

Type 2 diabetes – This is a lifestyle disease, and can be caused by obesity, genetics, inactivity, and/or poor diet choices. It develops as a metabolic disorder where the pancreas either makes very little insulin, or produces insulin that does not work well. This is also known as insulin resistance when the cells in muscles, fat, and the liver are not receptive to the insulin that is being produced, which means glucose is left in the blood instead of being used for energy or stored.

Gestational diabetes – This type of diabetes affects pregnant women, and is often resolved after the baby is born. It affects 2%–10% of women in the United States each year, often occurring when a woman is obese prior to pregnancy, or when they are carrying a larger baby that taxes their ability to secrete insulin. In instances where the mother experiences gestational diabetes, both the mother and child have a higher chance of developing type 2 diabetes later in life.

The differences in managing type 1 and type 2 diabetes

As an autoimmune disease, type 1 diabetes is unpreventable and irreversible. It requires more consistent attention, since a person will need to take a prescribed amount of insulin throughout the day in order to eat and engage in activity as normal.

Type 2 diabetes, on the other hand, can be reversible through lifestyle changes. Originally called adult-onset diabetes, type 2 diabetes has become more common in children and adolescents due to unhealthy diet, higher prevalence of obesity, and inactivity.

Prediabetes will occur before fully developing into type 2 diabetes. This occurs when blood sugar is trending higher than normal, but is not yet high enough to be diagnosed as diabetes. If blood sugar levels continue to go unchecked from eating excess sugar and refined and processed foods, type 2 diabetes will develop. The pace at which prediabetes turns into type 2 diabetes will depend upon the person, the quantities of sugar and carbohydrates they’re consuming, and how sedentary their lifestyle is.

When a person gains an understanding of how their blood sugar fluctuates from eating certain foods and engaging in certain types of physical activity throughout the day, they are better able to manage their health. Lifestyle changes can also prevent further health complications caused by persistent high blood sugar, like cardiovascular diseases, kidney disease, and nerve trouble. 

Four lifestyle habits to practice daily to manage diabetes:

     1.  Meal planning and timing

Eating three balanced meals each day that have a balance of complex carbohydrates, protein, healthy fats, and fiber is beneficial to ensure glucose levels stay stable, preventing dips that can cause one to feel unwell. Many of us have experienced low blood sugar before – headaches, feeling moody, even “hangry” – and for those with diabetes, these feelings are not only uncomfortable, but can be very detrimental to their health.

The most important food group to watch is carb intake. Carbohydrates are necessary for healthy blood sugar but also have the potential to cause spikes when you eat too much of the refined and processed kinds. Carbohydrates that fall low on the glycemic index contain fiber, slowing the release and breakdown of glucose in the blood and creating a steady stream of energy instead of an influx that can cause a spike and crash. Some great low glycemic carbohydrates include sweet potato, quinoa, and barley.

Everyone’s bodies are different, even those who experience the same type of diabetes, so each individual must learn how to identify the target blood sugar range that fits their body’s needs. They can do so with the help of their personal physician and even a dietitian or nutritionist.

To manage blood sugar levels, Sheri Vettel, RD, recommends setting a goal to fill half your plate with non-starchy vegetables (like leafy greens and bell peppers, for example) and then keep protein and starchy carbohydrates (like potatoes or bread) to a quarter of your plate each. You can then add your favorite healthy fats, such as olive oil or nuts, to add extra flavor and nutrition to your meal. “It’s helpful to keep the amount of carbohydrates eaten at each meal consistent day-to-day. The timing of meals will be important, too. Aim to eat every 3–4 hours to prevent your blood sugar levels from plummeting.”

     2.  Physical activity

Regular exercise is an important component in managing diabetes, as physical activity can improve insulin sensitivity for type 2 diabetics during and after exercise, as the muscles contract, making it easier for cells to let available insulin shuttle glucose into cells for energy. Exercise is also helpful for those with type 1 diabetes, because the insulin that your body obtains from medication will also become more available to cells. Physical activity also reduces the risk of developing cardiovascular diseases and obesity, conditions that diabetics are at risk for later in life.

Physical activity will lower a person’s blood sugar for up to 24 hours or more following a workout, which means that medication and food intake need to be planned accordingly. Whether a person is taking insulin injections or another type of drug, it’s important that they fuel themselves with complex carbohydrates or protein about a half-hour before a workout, so that blood sugar levels don’t get too low.

Sheri Vettel, RD, mentions that it’s very important to monitor blood sugar before, during, and after exercise. “This is especially true if you're just beginning to increase your physical activity levels or are on insulin or oral diabetes medications that are more likely to cause low blood sugar. It's helpful to discuss a plan around physical activity with your healthcare provider. For instance, depending on your blood sugar levels, you may need to modify the types of exercise that you can safely do. You'll also need to fuel your body accordingly based on your blood sugar readings. For example, if your blood sugar is less than 100 mg/dL prior to exercise, you'll need to consume at least 15–20 grams of carbohydrates – along with protein or fat – prior to exercise. A great example is a small apple or pear (sliced) and a tablespoon of nut butter.”

     3.  Medication

Medication is a common way that diabetics manage their blood sugar and insulin levels on a daily basis. For those with type 1 diabetes, the body cannot make any of its own insulin, so a person will need to take insulin injections multiple times a day. This could be a rapid-acting insulin (often used 15 minutes before a meal) or long-acting insulin (which lasts for up to 24 hours), depending on a person’s meal timing, nutritional needs, activity levels, and unique physiology.

Those with type 2 diabetes also have medication options to manage their health, including a variety of drugs that can promote insulin performance. These include medications that improve the sensitivity of cells to insulin, prevent the production and release of glucose from the liver, and even slow how quickly food moves through the digestive tract.

     4.  Emotional health and stress

Stress can increase your heart rate and cause the release of hormones like cortisol and adrenaline that spike blood sugar levels. Research also suggests that stress is a lifestyle factor that contributes to the development of type 2 diabetes, as stress hormones inhibit insulin-producing cells in the pancreas from working properly.

As you have likely experienced yourself, whether a person has diabetes or not, stress interferes with overall routine and can make it more difficult to stick to a schedule of taking care of oneself. Stress can cause overeating or to reaching for comfort foods high in sugar that spike dopamine levels. For those with diabetes who reach for the sweet treats when they’re stressed, it’s even more imperative to have a stress management routine that can reduce those cravings. It’s important to make time for self-care and relaxation, since excess stress takes a toll on both mental and physical health.

The risks of letting blood sugar levels go unchecked

Diabetes affects about 422 million people worldwide. This number has grown quickly over the past few decades as obesity has become more prevalent and poorer lifestyle and diet habits have become the norm.

In the short term, chronically high blood sugar levels, or hyperglycemia, can damage the vessels that supply blood to all of your organs. On the flip side, keeping blood sugar too low, or hypoglycemia, can lead to heart palpitations, shakiness, anxiety, and in severe cases, can cause a coma.

If a person is unable to adjust their lifestyle to regulate blood sugar, these conditions may lead to further complications, like kidney, eye, and liver damage and an increased risk of heart disease and stroke.

Managing diabetes requires sustainable lifestyle changes.

Whether you're living with type 1 diabetes, or have learned that you're on track to develop type 2 diabetes, the good news is that diet and lifestyle changes go a long way in managing this disease. As you learn how your body responds to different cues – hunger, medication, exercise, and stress – you'll become the expert on your body and how to keep it humming!

Learning how your unique body works is one of the key things we teach in our Health Coach Training Program curriculum. You'll learn foundational nutrition concepts, similar to what is covered here, in addition to how all the other areas of your life – your relationships, environment, and career – also play a major role in your well-being. These areas are what we call primary foods, making the food on your plate secondary. Curious as to why this concept is the secret to a Health Coach's success? Check out our Sample Class to get a sneak peek into how your life can change with our Health Coach Training Program.