Life Satisfaction and Psychological Distress in Relation to Mediterranean Lifestyle Adherence and Behavioural Correlates: Findings from the MEDIET4ALL International Survey.
Mediterranean lifestyle adherence, social participation, physical activity, and sleep-related characteristics were associated with life satisfaction and psychological distress, with insomnia severity emerging as the most consistent correlate across all psychological outcomes.
Key Findings
Results
Insomnia severity showed the strongest negative association with life satisfaction among all correlates examined.
Insomnia severity had a standardized beta coefficient of β = -0.19 for life satisfaction
This was the largest magnitude association observed for life satisfaction among all predictors tested
Life satisfaction was assessed using the Short Life Satisfaction Questionnaire (SLSQ)
Analysis was conducted using hierarchical multiple linear regression across 4010 adults from 10 countries
Results
Insomnia severity was also the strongest positive correlate of depression, anxiety, and stress across all psychological distress outcomes.
Beta coefficients for insomnia severity ranged from β ≈ 0.43 to 0.47 across depression, anxiety, and stress outcomes
These were the largest magnitude associations observed for any predictor of psychological distress
Psychological distress was assessed using the Depression Anxiety Stress Scales (DASS-21)
Insomnia severity's association with distress was substantially larger than any other correlate in the model
Results
Alcohol consumption was the second strongest positive correlate of psychological distress after insomnia severity.
Alcohol consumption showed beta coefficients of β ≈ 0.12 to 0.15 across depression, anxiety, and stress outcomes
Residence in Mediterranean countries was also positively associated with psychological distress (β ≈ 0.05 to 0.08)
This indicates that living in a Mediterranean country was associated with higher, not lower, distress scores in this sample
Results
Higher Mediterranean lifestyle adherence was positively associated with life satisfaction.
Mediterranean lifestyle adherence showed a positive association with life satisfaction with β ≈ 0.06 to 0.18 range reported for positive correlates
Mediterranean lifestyle was assessed using the validated MEDLIFE index, integrating dietary habits with indicators of physical activity, rest, and social/convivial habits
The sample included 4010 adults (59.5% female) from 10 Mediterranean and neighbouring countries
Results
Better subjective sleep quality, higher social participation, higher education, marital or cohabiting status, and better self-reported health were all positively associated with life satisfaction.
These positive correlates of life satisfaction had beta coefficients of β ≈ 0.06 to 0.18
Social participation was assessed with a validated measure as a complementary instrument beyond the MEDLIFE index
These findings emerged from hierarchical multiple linear regression analyses controlling for multiple factors simultaneously
Results
Higher body mass index, greater physical activity expenditure, higher insomnia severity, and residence in neighbouring/non-Mediterranean countries were associated with lower life satisfaction.
Negative correlates of life satisfaction had beta coefficients of β ≈ -0.05 to -0.19
Insomnia severity was the largest negative correlate at β = -0.19
Greater physical activity expenditure was negatively associated with life satisfaction, while physical activity levels were separately associated with lower distress
Results
Older age, better self-reported health status, and higher physical activity levels were consistently associated with lower psychological distress across all distress outcomes.
These protective factors showed beta coefficients of β ≈ -0.03 to -0.14 across depression, anxiety, and stress
Age was analyzed as a continuous variable in the regression models
Physical activity showed opposing associations depending on outcome: negatively associated with life satisfaction but negatively associated with distress
Results
Exploratory indirect-association analyses identified statistically significant indirect associations involving insomnia severity among Mediterranean lifestyle adherence, life satisfaction, and psychological distress.
Bootstrapped exploratory cross-sectional indirect-association analyses were used
Additional indirect statistical associations involving life satisfaction were observed among physical activity, social participation, and psychological distress outcomes
The magnitudes of the additional indirect associations involving life satisfaction were described as small
Authors explicitly stated these should be interpreted as 'hypothesis-generating and not as evidence of temporal ordering, causal mediation, or behavioural mechanisms'
Methods
The study sample comprised 4010 adults from 10 Mediterranean and neighbouring countries with a majority female composition.
59.5% of participants were female
Data were collected using a standardized multilingual e-survey (MEDIET4ALL survey)
Countries included both Mediterranean and neighbouring/non-Mediterranean nations
The cross-sectional design limits causal interpretation of all findings
What This Means
This research suggests that among more than 4,000 adults from 10 countries around the Mediterranean region, sleep problems — particularly insomnia — were the single most important factor linked to both lower life satisfaction and higher levels of depression, anxiety, and stress. Following a Mediterranean lifestyle (which includes healthy eating, physical activity, rest, and social habits) was associated with greater life satisfaction, as were better sleep quality, more social participation, being married or cohabiting, having higher education, and reporting better general health. Interestingly, living in a Mediterranean country was associated with higher psychological distress scores, suggesting that simply living in the region does not automatically confer mental health benefits.
The findings also showed that alcohol consumption was the second strongest factor associated with greater psychological distress, while older age and higher physical activity levels were linked to lower distress. The study used statistical methods to explore whether some factors might work through others — for example, whether insomnia might partly explain the relationship between Mediterranean lifestyle and mental health outcomes — but the authors caution that these exploratory analyses cannot establish cause and effect.
This research suggests that sleep health deserves particular attention in efforts to improve psychological wellbeing, even within populations living in or near the Mediterranean region known for its traditionally healthy lifestyle. Because this was a cross-sectional survey (a snapshot in time rather than a follow-up study), it is not possible to determine whether poor sleep causes psychological distress or vice versa. The results are intended to generate hypotheses for future research rather than to recommend specific interventions.
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Ammar A, Salem A, Trabelsi K, Montalvan M, Bouaziz B, Boujelbane M, et al.. (2026). Life Satisfaction and Psychological Distress in Relation to Mediterranean Lifestyle Adherence and Behavioural Correlates: Findings from the MEDIET4ALL International Survey.. Nutrients. https://doi.org/10.3390/nu18162708