**Background:** Nonalcoholic fatty liver disease (NAFLD) affects 25% of the global population and is the leading cause of chronic liver disease worldwide. Lifestyle modifications aimed at weight loss are the cornerstone of NAFLD management, yet only 30% of patients lose more than 5% of their body weight within 13 months. The Health Action Process Approach (HAPA) model, which divides behavior change into a motivational phase (risk perception, outcome expectancies, action self-efficacy, intention) and a volitional phase (action plans, coping strategies, maintenance/recovery self-efficacy, action control), has been used in various behavior change interventions but has not been applied to lifestyle adherence in NAFLD. This study aimed to use the HAPA model to examine factors affecting adherence to lifestyle prescriptions among patients with NAFLD.
**Methods:** This qualitative, descriptive study was conducted from July 2022 to September 2022 at the outpatient clinic of Beijing Youan Hospital. Thirty adult patients with NAFLD (diagnosed by B-type ultrasound or liver biopsy) were recruited using purposive sampling with maximal variation by age, gender, and time since diagnosis. Exclusion criteria included hepatitis B or C virus infection and diagnosis of liver cirrhosis or hepatocellular carcinoma. Semi-structured individual face-to-face interviews lasting 10–40 minutes were conducted by a researcher with qualitative research expertise, using an interview guide based on the HAPA framework. Interviews were transcribed verbatim and analyzed using both reflexive thematic analysis (following Braun and Clarke's six-step method) and framework analysis to identify naturally occurring themes and map them to HAPA domains. Two researchers (L.W. and H.Z.) independently coded the data, and themes were reviewed and refined against the dataset.
**Key Results:** The 30 participants had a mean age of 40.2 years (SD = 11.8, range 22–63). Half were women, 70.0% were married, 80.0% had undergraduate education or above, 46.7% were overweight, 40.0% were obese, and all had severe fatty liver disease. Comorbidities included dyslipidemia (73.3%), diabetes (23.3%), hyperuricemia (23.3%), and hypertension (13.3%). Thematic analysis produced multiple themes mapped to HAPA domains. For risk perception, most patients were aware that fatty liver could progress to cirrhosis and hepatocellular carcinoma but were less aware of risks for cardiovascular and cerebrovascular diseases. For outcome expectancies, positive expectations included fat loss, improved clinical indicators, and resolution of symptoms; the main negative outcome expectancy was fear of sports injury, particularly knee joint injuries among overweight/obese patients. Most patients lacked clear goals for fatty liver treatment. For action plans, patients desired simple, convenient, specific, and systematic plans with timetables for both physical activity and diet. Key barriers to physical activity included conditional limitations (adverse weather, poor air quality, COVID-19 quarantine), lack of time, fatigue, poor physical fitness, and fear of sports injury; women were more frequently hindered by housework. Key barriers to diet included diet environment (social gatherings, dinner parties) and psychological factors (mental stress, food cravings). All patients reported not knowing how to overcome these obstacles. Facilitators included developing coping strategies (alternative plans, starting with low exercise levels, advance food preparation), action control strategies (self-monitoring with activity trackers or food photos, home monitoring of weight/waist circumference, regular feedback from doctors, regular hospital follow-up), and self-efficacy enhancement (encouragement from doctors and family, mutual supervision among patients).
**Clinical Implications:** This study provides a patient-centered framework for designing lifestyle interventions for NAFLD by identifying specific, actionable factors within the HAPA model. The findings suggest that future lifestyle intervention programs should prioritize the volitional phase constructs—particularly action plans, coping strategies, action control, and self-efficacy—rather than solely focusing on motivation and risk perception. Clinicians should provide simple, specific, and individualized action plans for both exercise and diet; help patients develop coping strategies for anticipated barriers (e.g., adverse weather, social gatherings, fatigue); implement regular feedback mechanisms (e.g., follow-up visits, remote monitoring); and use tools such as pedometers, food diaries, and weight scales to enhance self-monitoring. The study also highlights the need for multidisciplinary support involving specialists, dietitians, and exercise physiologists to address the complex barriers to lifestyle adherence in NAFLD patients.