It is estimated that 1 in 11 adults have diabetes globally. Diabetes is responsible for 11% of deaths per year. Type 2 diabetes is the most common type of diabetes, accounting for 90-95% of cases.
Type 2 diabetes is a metabolic disorder that is characterized by insulin resistance and results in hyperglycemia (high blood glucose levels). Risk factors for type 2 diabetes include age, family history, ethnicity, and high blood pressure. The most common risk factor for type 2 diabetes is obesity.
Defining diabetes remission
The treatment and management of type 2 diabetes is vital to lower blood glucose levels. Diabetes remission is a temporary reduction in the severity of the disorder and is an important outcome for patients and clinicians. However, the definition of diabetes remission varies. Remission of diabetes mostly refers to a glycated hemoglobin (HbA1c) threshold, use of antidiabetic drugs, and duration of remission.1
What are carbohydrate-restricted diets?
Studying the management of diabetes through dietary interventions that restrict carbohydrate intake is useful to researchers, healthcare providers, and patients. The standard recommended intake of carbohydrates varies from 45-65% of daily calories.
Carbohydrate restriction has been used for years in the management of diabetes. Low carbohydrate diets indicate a carbohydrate intake of below 45% of daily calories. Very low carbohydrate diets range from less than 10% to 26% of daily caloric intake.
Low carbohydrate diets are controversial since they have been shown to induce nutritional ketosis. This is a process that occurs when the body has insufficient amounts of carbohydrates to burn for energy. Instead, the body burns fat to produce ketone bodies as an alternative energy source. Carbohydrate-restricted diets have numerous risks, including potential adverse health consequences due to high levels of saturated fat, nutrient deficiencies, and environmental and ethical concerns.
Carbohydrate restricted diets can help diabetes remission
Research published in British Medical Journal 2 investigated the effectiveness and safety of low carbohydrate and very low carbohydrate diets for patients with type 2 diabetes. This study was based on moderate to low certainty evidence from 23 randomized trials (1357 participants). Patients were eligible if they followed a low carbohydrate diet for at least 12 weeks, with or without exercise.
Low carbohydrate diets were compared to low-fat diets, since low-fat diets are also commonly recommended for managing type 2 diabetes. The primary outcomes of interest were diabetes remission, weight loss, HbA1c, fasting glucose, and adverse events. Secondary outcomes included quality of life and reduction of medication.
Low carbohydrate diet can help for managing diabetes
The study found that following a low carbohydrate diet for six months can lead to diabetes remission without any adverse complications. There was a significant increase in diabetes remission with low carbohydrate diets (32%).
A low carbohydrate diet in this study also decreased the use of medication and led to clinically important improvements in weight loss, triglyceride concentrations, and insulin resistance at six months. However, these benefits were less obvious at 12 months.
Participants did not experience any significant differences in their quality of life at six months. However, there was a clinically important (but not significant) worsening of quality of life in patients following a carbohydrate-restricted diet at 12 months.
Are there any negative effects?
This study was limited since it only focused on sticking to a low carbohydrate diet for the short-term for the management of type 2 diabetes. More research is needed to investigate the effectiveness, safety, health effects, and dietary satisfaction of long-term carbohydrate-restricted diets.
A review of clinical studies published in Lancet Public Health suggested that the long-term use of low carbohydrate diets may be associated with increased mortality rates.3
The study suggests that clinicians could consider the short-term use of a low carbohydrate diet for managing type 2 diabetes while monitoring and adjusting diabetes medication, as needed.
References:
1. Goldenberg J and Johnston B. (2021). Low and very low carbohydrate diets for diabetes remission. BMJ, 373(262). Retrieved from: https://www.bmj.com/content/373/bmj.n262
2. Goldenberg J, et al. (2021). Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data. BMJ, 372(4743). Retrieved from: https://www.bmj.com/content/372/bmj.m4743
3. Seidelmann S, et al. (2018). Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis. Lancet Public Health, 3(9), 419-428. Retrieved from: https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(18)30135-X/fulltext
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