By Brittany Bogusz, nutrition graduate student in the Coordinated Program
What is Type 2 Diabetes Mellitus?
Type 2 Diabetes Mellitus is the most common form of diabetes in the United States of America. About 34.2 million Americans are currently living with type 2 diabetes in 2020. When an individual has type 2 diabetes, it means his/her body does not use insulin properly. Insulin is a hormone produced by the pancreas that helps regulate the level of sugar in our blood. When the body cannot properly make enough insulin or use the insulin produced, blood sugar levels increase, causing hyperglycemia, which can present as frequent urination or increased thirst.
On the other hand, individuals with type 2 diabetes can also experience hypoglycemia, which is a decrease in blood sugar levels. Hypoglycemia symptoms include shakiness, sweating or chills, confusion, rapid heartbeats, lightheadedness or dizziness, hunger, nausea, and many more. A balanced diet with an adequate amount of nutrient-dense carbohydrates, protein, and fats is recommended to prevent both hyper- and hypoglycemic episodes in individuals with type 2 diabetes. However, it is thought that high-protein, low-carbohydrate diets may promote weight loss, improve blood lipid and glucose levels, and maintain lean body mass in subjects with type 2 diabetes mellitus.
What is the Keto diet?
The keto diet is a new trend that has grabbed the attention of many people all around the country to manage type 2 diabetes. The popular keto diet is a diet that involves eating a low amount of carbohydrates (less than 50 grams per day) and a high amount of protein and fats. When an individual eats low amounts of carbohydrates (around 50 grams or less), the body shifts from using glucose/sugar as a fuel source to using ketone bodies. Ketones are created by the liver from stored fat, called ketogenesis.
What happens what individuals with T2DM follow a low-calorie ketogenic diet?
When individuals diagnosed with type 2 diabetes, who are also classified as obese and follow a strict very-low-calorie ketogenic diet, both positive and negative outcomes may occur. In a recent study by Gramer, et al., 45 men and women, ages 30-65 years of age, followed a stringent low-calorie ketogenic diet, consisting of 600-800 calories per day and less than 50 grams of carbohydrates per day for six weeks. It is important to note that this calorie intake is very difficult to maintain long-term and was followed under research conditions for a short time. It is recommended that individuals with diabetes consume around 200-225 grams of carbohydrates per day to prevent low blood sugar. In addition to these 45 participants, another group of 44 men and women, ages 30-65 years of age, followed a standard low-calorie diet, where participants followed a diet with an energy restriction of 500-100 calories per day.
All the study participants had type 2 diabetes, were classified as obese, and were not prescribed insulin therapy. The study found that diabetic patients, without insulin therapy, following a very-low-calorie ketogenic diet experienced weight loss of 5-10% or greater. Participants in the standard low-calorie diet also experienced weight loss. In addition to weight loss, participants in both the very-low-calorie ketogenic diet group and standard low-calorie diet group experienced decreased fasting blood glucose levels, hemoglobin A1c levels, total cholesterol, triglycerides and LDL-c levels. However, these decreases were more significant among participants following the very-low-calorie ketogenic diet. The decrease in carbohydrate intake among both groups may play a factor in decreased fasting blood glucose levels and hemoglobin A1c levels, therefore potentially managing a diabetes diagnosis.
Adverse effects of ketogenic diets
When following any restrictive diet, negative side effects may occur. Type 2 diabetes can cause increases and decreases in blood sugar levels, depending on what is eaten. When a large amount of carbohydrates is eaten, blood sugar levels can increase. On the other hand, when not enough carbohydrates are eaten, blood sugar levels can increase and cause side effects such as headaches, shakiness, nausea, dizziness, and vomiting. Many individuals following a very-low-calorie ketogenic diet within the study reported adverse effects, such as headaches, constipation, nausea, and vomiting. The most common side effect reported at the end of the six-week study among the very-low-calorie ketogenic group participants was constipation and orthostatic hypotension, a quick decrease in blood pressure when standing.
Although the ketogenic diet shows short-term safety and efficacy, the long-term effects are unknown. It is recommended that more research be conducted. This study shows the type 2 diabetes can be managed short-term with a very-low-calorie ketogenic diet and a standard low-calorie diet. Once again, it is important to note that these results occurred under a controlled scientific study and that maintaining this type of diet can be extremely difficult. A doctor should supervise any very low-calorie diet. In addition, the 2015-2020 Dietary Guidelines recommend a daily calorie intake of 1600-1800 calories for sedentary women, ages 30-65, and 2000-2400 calories for sedentary men, ages 30-65. Therefore, this study used diets that were well below the dietary recommendations, even for sedentary individuals. Individuals diagnosed with type 2 diabetes should seek a registered dietitian and physician's advice to develop the best plan of action to manage the diagnosis.