Diet and Lifestyle Factors Associated with Gastrointestinal Symptoms in Spanish Adults: Cross-Sectional Analysis of the 2023 Spanish National Health Survey

Background/Objectives: Digestive problems are common in the general population and may be influenced by lifestyle, emotional status and diet. This study aimed to estimate the prevalence of digestive problems in Spanish adults and examined associated factors. Methods: Descriptive cross-sectional analysis of anonymized adult microdata from the 2023 Spanish Health Survey was performed. Data were collected using a mixed-mode design (self-administered web questionnaire with interviewer-administered follow-up). Digestive problems were recoded by combining gastric ulcer, constipation, and prescribed use of laxatives, astringent drugs, and stomach medication. Therefore, digestive problems are primarily defined as the presence of gastric ulcers, diarrhea, and/or constipation. Variables included sociodemographic, Body Mass Index (BMI), smoking, alcohol intake, physical activity, Personal Health Questionnaire Depression Scale (PHQ-8), World Health Organization Well Being Index (WHO-5), and macronutrient intake estimated from a Food-Frequency Questionnaire using the Spanish Food Composition Database (BEDCA). Group comparisons and multivariable logistic regression were conducted (95% CI; significance level set at p < 0.05). Results: Of 34,148 participants, 13,518 provided information on digestive problems; among these respondents, 3860 (28.6%) reported having digestive issues. Prevalence ranged from 5.2% to 36.5% among national territories. Higher odds (OR) of digestive problems were associated with age (OR 1.026, 95% CI 1.023–1.029), female sex (OR 1.168, 1.070–1.276), non-smoking (OR 1.240, 1.005–1.531) and ex-smoking (OR 1.447, 1.272–1.647) compared to current smokers, higher PHQ-8 scores (OR 1.040, 1.029–1.051), greater protein intake (OR 1.016, 1.009–1.023), consumption of sweet pastries (OR 1.058, 1.039–1.077), and dairy products (OR 1.027, 1.002–1.053); in contrast, lower odds were associated with higher WHO-5 scores (OR 0.985, 0.982–0.987), total fiber intake (OR 0.968, 0.949–0.987), and legume consumption (OR 0.894, 0.856–0.933). Conclusions: Digestive problems show considerable variability in prevalence among survey-based Spanish sample. Digestive problems were associated with older age, female sex, depressive symptoms, high-protein intake, and higher consumption of sweet pastries and dairy products, whereas higher well-being scores, higher fiber intake and legume consumption were associated with lower odds of digestive problems.