Outcomes of a Digitally Delivered Low-Carbohydrate Type 2 Diabetes Self-Management Program: 1-Year Results of a Single-Arm Longitudinal Study

Abstract

Background: Type 2 diabetes mellitus has serious health consequences, including blindness, amputation, stroke, and dementia, and its annual global costs are more than US $800 billion. Although typically considered a progressive, nonreversible disease, some researchers and clinicians now argue that type 2 diabetes may be effectively treated with a carbohydrate-reduced diet.

Objective: Our objective was to evaluate the 1-year outcomes of the digitally delivered Low-Carb Program, a nutritionally focused, 10-session educational intervention for glycemic control and weight loss for adults with type 2 diabetes. The program reinforces carbohydrate restriction using behavioral techniques including goal setting, peer support, and behavioral self-monitoring.

Methods: The study used a quasi-experimental research design comprised of an open-label, single-arm, pre-post intervention using a sample of convenience. From adults with type 2 diabetes who had joined the program and had a complete baseline dataset, we randomly selected participants to be followed for 1 year (N=1000; mean age 56.1, SD 15.7 years; 59.30% (593/1000) women; mean glycated hemoglobin A_1c (HbA_1c) 7.8%, SD 2.1%; mean body weight 89.6 kg, SD 23.1 kg; taking mean 1.2, SD 1.01 diabetes medications).

Results: Of the 1000 study participants, 708 (70.80%) individuals reported outcomes at 12 months, 672 (67.20%) completed at least 40% of the lessons, and 528 (52.80%) completed all lessons of the program. Of the 743 participants with a starting HbA_1c at or above the type 2 diabetes threshold of 6.5%, 195 (26.2%) reduced their HbA_1c to below the threshold while taking no glucose-lowering medications or just metformin. Of the participants who were taking at least one hypoglycemic medication at baseline, 40.4% (289/714) reduced one or more of these medications. Almost half (46.40%, 464/1000) of all participants lost at least 5% of their body weight. Overall, glycemic control and weight loss improved, especially for participants who completed all 10 modules of the program. For example, participants with elevated baseline HbA_1c (≥7.5%) who engaged with all 10 weekly modules reduced their HbA_1c from 9.2% to 7.1% (P<.001) and lost an average of 6.9% of their body weight (P<.001).

Conclusions: Especially for participants who fully engage, an online program that teaches a carbohydrate-reduced diet to adults with type 2 diabetes can be effective for glycemic control, weight loss, and reducing hypoglycemic medications.

Keywords: diet; eHealth; type 2 diabetes mellitus; weight loss.

Figure 1

Study participant flowchart for the study.

Figure 2

Mean glycated hemoglobin A_1c (HbA_1c) levels at baseline and 1-year follow-up for participants who completed the program (engaged with all 10 weekly Low Carb Program modules). Error bars represent the SD; * represents significant difference from baseline.

Figure 3

Mean weight at baseline and 1-year follow-up for participants who completed the program (engaged with all 10 weekly Low Carb Program modules). Error bars represent the SD; * represents significant difference from baseline.

Figure 4

Frequency of change in the number of medications taken for all completers. Bars represent total users of each drug type with the type of change (increase, no change, or elimination) stacked within the bar and the relative frequency noted next to each section. The total number of users of each medication type is noted at the top of each bar.