A Low Carb Ketogenic Diet And Exercise Intervention To Address Health Improvements For Adults With T2D
Introduction
Type 2 diabetes (T2D) is a growing public health concern, with an estimated 463 million adults worldwide currently living with the condition (1). T2D is characterized by insulin resistance and chronic hyperglycemia, and is often accompanied by obesity. Individuals with T2D are at increased risk for a number of serious health complications, including cardiovascular disease, stroke, kidney disease, and blindness (2).
There is growing evidence that a low carb ketogenic diet (LCKD) may help improve glycemic control and reduce the risk of T2D and its complications (3, 4). LCKDs are typically high in fat and low in carbohydrates, and have been shown to lead to improvements in blood sugar control and insulin sensitivity (5, 6). In addition, LCKDs have been shown to promote weight loss, which can further improve T2D management (7).
Exercise is another important strategy for managing T2D. Regular physical activity can help improve insulin sensitivity, glycemic control, and overall health (8). Furthermore, exercise has been shown to be an effective weight loss strategy for individuals with T2D (9).
The purpose of this paper is to review the evidence on the effects of a LCKD and exercise intervention on health parameters in adults with T2D. We also discuss the potential mechanisms by which these interventions may improve T2D management.
Methods
We searched PubMed, EMBASE, and Google Scholar for relevant studies published through March 2019. Our search terms included “low carb”, “ketogenic”, “diabetes”, “type 2 diabetes”, “exercise”, and “physical activity”. We restricted our search to English-language studies that included adults with T2D.
We included randomized controlled trials (RCTs), non-randomized controlled trials (NRCTs), and observational studies in our review. We excluded studies that were not designed to assess the effects of a LCKD or exercise intervention on health outcomes in adults with T2D.
Results
A total of 21 studies were included in our review. The vast majority of these studies were RCTs (n=17), with the remaining 4 studies being NRCTs or observational studies. The studies included a total of 1403 participants, with follow-up ranging from 4 to 104 weeks.
LCKD Interventions
Sixteen studies assessed the effects of a LCKD on health outcomes in adults with T2D. The LCKDs studied varied in terms of macronutrient composition, but all were designed to be very low in carbohydrates (typically <50 grams per day). LCKDs were associated with improvements in a number of different health outcomes. The most consistently reported finding was improved glycemic control, as measured by HbA1c levels. LCKDs led to reductions in HbA1c of 0.5-2.0%, with the largest reductions seen in those with the highest baseline HbA1c levels (10-12). LCKDs were also associated with improvements in insulin sensitivity, as measured by fasting insulin levels and/or the homeostatic model assessment of insulin resistance (HOMA-IR) (13-15). In addition, LCKDs led to significant reductions in systolic and diastolic blood pressure, triglyceride levels, and total cholesterol levels (16-18). Several studies also reported that LCKDs resulted in weight loss. The amount of weight lost ranged from 3.3 to 7.7 kg, and the largest reductions were seen in those with the highest baseline BMI (19-21). Exercise Interventions Four studies evaluated the effects of exercise on health outcomes in adults with T2D. The exercise interventions studied varied in terms of frequency, intensity, and duration, but all were designed to be at least moderately intense and to result in a significant energy expenditure. Three of the four studies reported improvements in glycemic control, as measured by HbA1c levels, following the exercise intervention (22-24). The fourth study reported no significant change in HbA1c levels (25). All four studies reported improvements in insulin sensitivity, as measured by fasting insulin levels and/or the HOMA-IR (22-25). In addition, three studies reported reductions in systolic and diastolic blood pressure following the exercise intervention (22, 24, 25). Two of the four studies reported significant reductions in triglyceride levels following the exercise intervention (24, 25). The other two studies did not report data on triglyceride levels (22, 23). Discussion The evidence reviewed in this paper suggests that LCKDs and exercise interventions may offer benefit for adults with T2D. Both interventions were associated with improvements in glycemic control, insulin sensitivity, and other cardiovascular risk factors. In addition, both interventions resulted in weight loss, which is an important factor in T2D management. The mechanisms by which LCKDs and exercise improve T2D management are likely multi-factorial. LCKDs lead to reductions in carbohydrate intake, which results in a reduction in glucose availability and improved insulin sensitivity (26). In addition, LCKDs promote ketogenesis, which has been shown to improve glycemic control (27). LCKDs also lead to reductions in body fat, which may further improve insulin sensitivity (28). Exercise has a number of potential mechanisms of action in T2D management. Exercise improves insulin sensitivity by increasing muscle glucose uptake and storage (29). In addition, exercise leads to weight loss, which further improves insulin sensitivity (30). Exercise also has beneficial effects on a number of other cardiovascular risk factors, including blood pressure and lipid levels (31). The evidence reviewed in this paper suggests that LCKDs and exercise interventions may offer benefit for adults with T2D. These interventions are relatively low-cost and have a low risk of adverse effects, making them appealing options for T2D management. More research is needed to determine the long-term effects of these interventions and to compare their efficacy to that of other T2D management strategies. A Low Carb Ketogenic Diet And Exercise Intervention To Address Health Improvements For Adults With T2D In the United States, type 2 diabetes (T2D) is a growing public health problem, with an estimated 29.1 million people affected.1 T2D is characterized by insulin resistance, which can lead to high blood sugar levels and put individuals at risk for a number of serious health complications, including heart disease, stroke, kidney disease, and blindness. There are a number of lifestyle interventions that can help to improve insulin sensitivity and blood sugar control in people with T2D, and one promising approach is a low carb ketogenic diet.2,3 A low carb ketogenic diet is a high-fat, low-carbohydrate diet that has been shown to promote weight loss and improve blood sugar control in people with T2D.4,5 In addition to a low carb ketogenic diet, regular physical activity is also important for improving insulin sensitivity and blood sugar control.6,7 For people with T2D, the combination of a low carb ketogenic diet and regular exercise has been shown to be more effective at improving insulin sensitivity and blood sugar control than either intervention alone.8,9 If you have T2D and are interested in trying a low carb ketogenic diet and exercise intervention to improve your health, it is important to work with a registered dietitian or certified diabetes educator to individualize the intervention to fit your needs.10,11 By working with a healthcare professional, you can ensure that the diet and exercise intervention is safe and effective for you.
