An urgent need exists for comparative-effectiveness research to evaluate novel interventions.30,31
This single-center randomized controlled trial is one of the first trials reported to compare the effect of group training in mindful eating to group self-management education in adults with T2DM. Outcomes comparing weight and glycemia were comparable between the two interventions and indicate modest reductions in body weight and A1c.
A meta-analysis evaluating the effect of nutrition counseling on weight loss found a change of −0.1 BMI unit per month during 3–12 months of treatment.32
Another meta-analysis reported a loss of 1.7 kg following a lifestyle intervention in adults with T2DM compared to usual care.33
Both analyses found less weight loss among people with T2DM than among those without diabetes. Weight loss among participants in the SC group in the present study was greater than those observed in these prior reports. The Look AHEAD trial also investigated the impact of an intensive lifestyle intervention in adults with T2DM. In Look AHEAD, participants in the intensive intervention lost 8.71 kg after 1-year of treatment.34
The Look AHEAD intervention included a longer time period (12 months) than the current study (3 months), provided participants with meal replacements free of charge, and emphasized physical activity. Food was not provided to participants in the current study. Instead, participants purchased and prepared their own food and were encouraged to modify intake based on awareness of hunger and satiety cues in MB-EAT-D or self-selected goals in SC. Both mindful awareness of hunger and goal setting strategies were effective in helping participants reduce energy intake and lose weight.
Studies regarding the effect of changes in diet and/or physical activity on weight control found interventions that targeted both diet and physical activity rather than only one of these behaviors promoted a 2–3 kg greater weight change.32,35,36
Increasing physical activity was not the primary focus of either the MB-EAT-D or SC interventions. MB-EAT-D focused primarily on eating regulation; body awareness and physical activity were discussed but MB-EAT-D did not emphasize activity at a level of intensity to promote weight loss. Therefore, SC also did not place as much emphasis on physical activity as dietary change to enable a comparable evaluation of dietary change across intervention conditions and only one session in each intervention focused on physical activity. No significant increase in physical activity occurred in this study. Prior studies found greater weight loss when changes in both diet and physical activity were promoted.35,37
Thus, greater weight loss would likely be observed following the current interventions with more emphasis directed toward physical activity; future research should evaluate the magnitude of weight loss with this added emphasis.
Significant reduction in energy intake occurred for both groups following the interventions. In addition, significant improvement in intake of trans fats, fiber and glycemic load occurred. SC included five sessions on dietary fats, carbohydrates and glycemic index combined and considerable time was spent on strategies and skill-building for improving intakes. MB-EAT-D provided less detailed information on MNT due to the time spent in meditation practice during group sessions. Thus, the dietary changes observed are consistent with the focus of each intervention.
Participants in the current study had significant improvement in A1c, and the improvement in glycemia was similar to that observed previously. Look AHEAD participants in the intensive intervention had a mean reduction in A1c of −0.643% at 1-year.34
A 6-week group-based intervention, which included diabetes education, cognitive behavioral approaches, goal-setting, and problem-solving regarding diabetes management, observed a mean reduction in A1c of −0.82% at 3-months.38
Mean reduction in A1c was −0.27% following four 2-hour group-based DSME sessions in primary care patients.39
A pilot study that involved implementation of an 8-week mindfulness intervention resulted in a mean reduction in A1c of −0.48% 1-month following the intervention.19
Thus, glycemia was improved in both DSME-based and mindfulness-based interventions in the current and prior studies. A reduction in A1c of −0.67% to −0.83% observed at 3-month follow-up in this study, if sustained over the long term, could result in significant reduction in microvascular and cardiovascular end points.40–42
The identification of effective treatment approaches that improve diabetes outcomes is necessary to meet the educational needs of the escalating diabetes population. People with diabetes need the necessary knowledge and skills to modify behavior and successfully self-manage the disease. Few randomized trials have been conducted to compare alternative models for delivering patient education and MNT. DSME is widely endorsed through diabetes practice guidelines.4
However, little research has evaluated the impact of mindful eating on diabetes outcomes. Results from the current study indicate training in mindful eating is feasible, well accepted, and effective in promoting modest weight loss. Prior research found behavioral lifestyle interventions, similar to the MB-EAT-D and SC interventions, which provided instruction, modeling, goal setting, and problem-solving also helped participants integrate diet and physical activity behaviors into their self-care and facilitated improvement in glycemic control.5,38
The availability of multiple effective educational approaches to diabetes self-management will likely improve treatment adherence among patients and is a necessary first step in treatment evaluation. However, educators and clinicians need to know not only that a treatment works on average but also which intervention works best for specific types of patients and the conditions under which each treatment is most effective. The answer to these questions was beyond this pilot study, and future research is needed to determine delivery of the right educational approach to the right patient at the right time.
Despite the comparative effectiveness findings, some limitations of the study should be noted. First, the sample had limited racial and ethnic diversity; replication of the study with more diverse populations would be desirable. Second, 24% of participants enrolled in the study withdrew prior to completing the interventions, which prevented adequate testing of hypotheses. The findings obtained from this study enable estimates of effect sizes for a future larger study. It should be noted that other studies experienced similar rates of attrition from group-based interventions.38,39
This study required a significant time commitment with a predefined group schedule and participants were randomly assigned to treatment group. Of the 16 participants who withdrew prior to completing their assigned intervention, 7 withdrew due to scheduling conflicts and competing time demands. Whether greater retention would be achieved by allowing participants to self-select their intervention condition requires additional research. However, non-randomized designs pose threats to validity. Finally, the long-term impact of the MB-EAT-D and SC interventions beyond 3-months is not known, and future research should evaluate the long-term impact on outcomes.
In summary, the present results suggest that adults with T2DM can modify their dietary intake to achieve weight loss and improve glycemia regardless of whether they receive training in mindful eating or MNT for diabetes self-management. Maintenance of weight loss and optimal glycemia are associated with reductions in the morbidity associated with diabetes. Future research should examine preferences for treatment focus (i.e., MNT only versus mindful eating only versus combined treatment) and whether the magnitude of change is greater when patients select one approach over another. Alternatively, some diabetes patients may prefer to complete a DSME-based program first to learn the fundamentals of MNT and self-management followed by a mindful-eating intervention to facilitate maintenance of change. Eating in response to bodily awareness and hunger cues offers the opportunity to develop self-management skills for weight maintenance. The availability of several effective treatments allows patients greater choice in meeting their self-care needs and enables clinicians to tailor diabetes programs.