Investigating the relationship between inhibitory control and dietary adherence among patients with type 2 diabetes mellitus based on subjective and objective measures

Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease globally, posing a significant public health challenge, particularly in China. Effective dietary management is crucial for T2DM control, yet adherence to recommended diets remains a major obstacle. This low adherence is often attributed to difficulties in resisting food cravings and temptations. Inhibitory control, a key component of executive function, plays a critical role in self-regulation and decision-making, including the ability to resist impulses and make long-term choices. While research suggests a link between inhibitory control and eating behavior, few studies have explored this relationship specifically in T2DM patients. This study aimed to investigate the association between inhibitory control and dietary adherence in T2DM patients using both subjective and objective measures of inhibitory control, providing a more comprehensive understanding of this relationship and potential avenues for improved dietary management.

Existing literature demonstrates the significant impact of impaired inhibitory control on eating behavior. Individuals with poorer inhibitory control struggle to resist food temptations, often opting for high-calorie options, leading to overeating, weight gain, and obesity. Conversely, better inhibitory control is associated with increased consumption of fruits and vegetables. Intervention studies have shown that training inhibitory control can reduce preferences for high-calorie foods and snack consumption. However, previous studies primarily focused on restrictive dieters, individuals with eating disorders, or overweight/obese populations, with limited research on patients with chronic conditions requiring long-term dietary management, such as T2DM. This study addresses this gap by examining the relationship in a T2DM population.

A cross-sectional study design was employed, recruiting 393 T2DM patients from three tertiary hospitals in China using convenience sampling. Inclusion criteria included meeting the 1999 WHO diagnostic criteria for diabetes, a disease course of at least six months, age 18 years or older, good verbal communication skills, normal or corrected vision, normal finger function, a Montreal Cognitive Assessment (MoCA) score ≥ 25, and informed consent. Patients with a history of cerebrovascular disease or central nervous system injury, or difficulty completing assessments were excluded. Dietary adherence was assessed using the Dietary Behavior Adherence Scale for Patients with Type 2 Diabetes Mellitus (DBA-T2DM). Inhibitory control was measured subjectively using the BRIEF-A inhibitory control subscale and objectively using the stop signal task (SST) and the Stroop task. Data were analyzed using descriptive statistics, Pearson correlation analysis, and hierarchical regression analysis to determine the relationship between inhibitory control and dietary adherence, controlling for demographic and clinical variables.

The study included 393 T2DM patients (78.88% male; mean age 51.55 ± 11.45 years; mean disease duration 9.46 ± 6.26 years). Dietary adherence varied significantly across age, gender, education level, history of hypoglycemia, and BMI. Subjective measures of inhibitory control (BRIEF-A) showed a significant negative correlation with the total dietary adherence score and all its dimensions (p < 0.05), indicating that better inhibitory control was associated with better dietary adherence. Hierarchical regression analysis revealed that subjective inhibitory control significantly predicted dietary adherence (p < 0.001), even after controlling for demographic and clinical factors. The model explained an additional 6.9% of the variance in dietary adherence. In a separate analysis with a subset of 101 participants who completed the objective measures, the Stroop effect (a measure of interference inhibition) was significantly negatively correlated with carbohydrate and fat adherence behavior (r = -0.244, p = 0.014). Hierarchical regression analysis showed that the Stroop effect significantly predicted carbohydrate and fat adherence behavior (p = 0.006), accounting for an additional 6% of the variance. However, SST performance (response inhibition) was not significantly associated with dietary adherence.

The study's findings support the hypothesis that inhibitory control is a significant predictor of dietary adherence in T2DM patients. Both subjective and objective measures of inhibitory control, albeit differently, showed a relationship with adherence. The strong association between subjective inhibitory control and overall dietary adherence highlights the importance of self-perceived ability to control impulses in influencing dietary behavior. The significant relationship between the Stroop effect and adherence to carbohydrate and fat intake suggests that the ability to manage interference from irrelevant information (e.g., tempting foods) is crucial for maintaining a healthy diet. The lack of association with the SST may indicate that general response inhibition is less important than interference inhibition or self-reported inhibitory control in the context of dietary adherence to T2DM guidelines. These findings offer valuable insights into the complex interplay between cognitive abilities and behavioral outcomes in the management of T2DM, suggesting that cognitive interventions may be beneficial.

This study provides robust evidence for the relationship between inhibitory control and dietary adherence in T2DM patients using both subjective and objective measures. Inhibitory control emerged as a significant predictor of adherence, underscoring the potential of interventions aimed at improving cognitive control to enhance dietary management. Future research should explore the effectiveness of inhibitory control training programs in improving dietary adherence among T2DM patients and investigate the neural mechanisms underlying this relationship using neuroimaging techniques.

The study's limitations include its cross-sectional design, which prevents causal inferences. The convenience sampling may limit the generalizability of the findings. Further, the relatively small number of participants in the objective inhibitory control task analyses may have reduced the power to detect certain effects. Future longitudinal studies with larger, more representative samples are needed to confirm these findings and to explore the causal direction of the observed relationships.