How is type 1 diabetes different from type 2 diabetes?

While both types of diabetes are characterized by high blood sugar and share in many clinical symptoms, type 1 diabetes is distinct from type 2 diabetes. Conventionally, type 1 diabetes is known as a genetic disorder where the immune system self-destructs the pancreatic beta-cells responsible for insulin production. On the other hand, type 2 diabetes is known to be closely associated with insulin resistance and obesity that leads to dysfunction in insulin secretion and sensitivity. Development of either types of diabetes involves multifaceted contributors, a combination of both genetic and environmental factors (e.g. diet, viral infections).

Nonetheless, recent studies show an increasing evidence of a complex interplay among roles of insulin resistance and obesity, as well as islet autoimmunity affecting all types of diabetes. Also, it had been known that development of type 1 diabetes is more common during childhood, and rare during adulthood. However, scholars now speculate that prevalence of type 1 diabetes may be underestimated in the adult population, with more patients developing T1D later in adulthood and/or being misdiagnosed with type 2 rather than type 1 diabetes.

What is the current guideline for treatment of T1D?

Since type 1 diabetes is yet to have a cure, the management goal is to control blood sugar and reduce secondary complications. In order to achieve glycemic control, insulin therapy is the single most important for those with type 1 diabetes. Nowadays, insulin pump therapy is preferred, where a patched device releases basal and bolus doses of insulin into your body. Basal insulin is released in a steady and continual flow throughout the day, whereas administration of bolus doses is often initiated by the patient before each mealtime. 

Along with insulin therapy, T1D patients may include other methods into their management plan, such as medications, exercise, and alternative diets. An addition of lifestyle changes is especially beneficial because it can help type 1 diabetes patients to more efficiently take control of their blood glucose levels.

What benefits do ketogenic diets (keto) have for T1D?

Studies done on keto’s effects on T1D are not as conclusive or prevalent as those on T2D. The ones that have been published so far are also controversial. Yet, some publications do suggest similar benefits of ketogenic diet for T1D patients as for T2D.

• Less insulin dose required: It can often become tricky for T1D patients to know how to adjust their insulin based on their carb intake at a given time. They need to continuously balance between not going above their target range into high blood glucose (hyperglycemia) but also not dropping down to be in the danger zone of low blood glucose (hypoglycemia). A study (Rajan et al., 2017) reports a reduction of about half of total insulin dose required for euglycemia in T1D patients on a low-carb diet (< 50g carb/day). Low-carb food choices can allow minimal fluctuations of glucose. In fact, it is believed that this low-carb + low-insulin combination is likely to help reduce risks of hypoglycemia since you are less likely to over-administer insulin.

• Changes in gut microbiota: Changes in gut microbiota can affect autoimmunity, contributing to the development and progression of type 1 diabetes. A 2017 study (Choi et al., 2017) reported that a fasting-mimicking diet (low-carb, low-calorie, low-protein, high-fat) was able to reverse insulin deficiency defects in human cells derived from autoimmune T1D patients.

• Reduction of HbA1c and improved glycemic control: An observational study (Leow et al., 2018) reports decreases in HbA1c levels, where the goal is below 7.0%. T1D patients on keto (< 55g carb/day) also reported reduction in variability of glucose throughout the day.

• Minimization of risks for secondary complications: Having long-term glycemic control can lead to better outcomes of microvascular and macrovascular complications (such complications include stroke, narrowed blood vessels, and damages to nerves, retina, and/or kidneys).

What are words of caution for T1D patients thinking of pursuing a ketogenic diet?

Just as for anyone going on a ketogenic diet for medical purposes, frequent monitoring of glucose and ketone levels is crucial for type 1 diabetes patients. Moreover, because of increased risk for T1D patients to develop diabetic ketoacidosis (DKA) or hypoglycemia, it is highly recommended that they follow guidance of a medical provider and/or a certified dietician throughout the process, especially in the transitional stage. They may need frequent adjustments of both basal and bolus doses of insulin as they start the diet. A device called continuous glucose monitor (CGM) may be discussed with a provider as this provides a way to automatically and continuously monitor blood glucose to minimize risks of hypoglycemia. 

In addition, medications that patients had been taking may need to be discontinued. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors, especially, has been associated with an increased risk of euglycemic DKA. Glucagon-like peptide-1 (GLP-1) receptor agonists should also be used with close monitoring or discontinued. Metformin is thought to be safe while on keto, but all adjustments should be discussed with providers and/or diabetes consultants.

In order to keep healthy lipid profiles and to help reduce risks of dyslipidemia and other cardiovascular complications, keto diet should be nutritionally well-balanced through a combination of vegetables, legumes, fruits, eggs, fish, nuts and seeds, in addition to meat. Patients should keep well-hydrated and replenish electrolytes (e.g. sodium, magnesium, potassium).

Most studies done on keto for pediatric patients with T1D has been for the treatment of epilepsy. According to several case studies, children have also benefited from keto in similar ways. However, potential complications (e.g. eating disorders, DKA, hypoglycemia, fatigue, and kidney stones, growth deficits) warrant a more cautious approach to using keto for T1D pediatric patients.