Summary: In this prespecified secondary analysis of a 12-week, four-arm randomised trial in 197 Spanish adults aged 30 to 60 with overweight or obesity, adding an 8-hour time-restricted eating window (early, late, or self-selected) to usual care was not associated with significant changes in objectively measured sleep, mood, or quality of life compared with usual care alone. Total sleep time differed by only 0.2 hours (95% CI, -0.2 to 0.6) for early time-restricted eating versus usual care, and all other contrasts were similarly null.
PICO Summary
| Element | Detail |
|---|---|
| Population | 197 adults aged 30 to 60 with overweight or obesity (98 women [49.7%]; mean age 46.1 years; mean BMI 32.8). Prespecified secondary analysis of a parallel-group randomised clinical trial conducted at two centres in Spain (NCT05310721). |
| Intervention | An 8-hour time-restricted eating window added to a Mediterranean-diet usual-care programme, over 12 weeks, in three schedules: early (start before 10 am, n=49), late (start after 1 pm, n=52), and self-selected window (n=47). |
| Comparison | Usual care alone (n=49): Mediterranean-diet education with the habitual eating window of 12 hours or more daily. |
| Outcome | No significant between-group differences. Early time-restricted eating versus usual care: total sleep time (accelerometry) mean difference 0.2 hours (95% CI, -0.2 to 0.6); Beck Depression Inventory Fast Screen 0.2 points (95% CI, -1.0 to 1.3); State-Trait Anxiety Inventory state anxiety -1.2 points (95% CI, -6.4 to 4.1); Perceived Stress Scale 2.1 points (95% CI, -1.8 to 5.9); Rand SF-36 general health 3.3 points (95% CI, -4.4 to 10.9). Late and self-selected schedules, and all between-TRE contrasts, were also non-significant. No formal ARR or NNT applies to these continuous null outcomes. |
Time-restricted eating and sleep, mood, and quality of life
RCT secondary analysis · overweight/obesity · 12 weeks
Adding an 8-hour time-restricted eating window to usual care did not improve or worsen sleep, mood, or quality of life over 12 weeks. The tight, near-zero confidence intervals make this an informative null rather than an underpowered miss.
Expert Commentary
This prespecified secondary analysis delivers a clean null result: across three eating-window schedules, time-restricted eating layered onto a Mediterranean usual-care programme was not associated with changes in sleep, mood, or quality of life over 12 weeks. The verdict is reassurance rather than benefit. Confidence intervals were tight and centred near zero, so these are informative null findings rather than an underpowered failure to detect an effect, and the use of accelerometry for sleep is a methodological strength over self-report alone. The principal limitation is that this is a secondary analysis: the parent trial was powered for cardiometabolic endpoints, not for these psychological and sleep outcomes, so the study cannot exclude smaller effects, and the 12-week horizon says nothing about longer-term adherence or mood. Participants were a relatively healthy, narrow age band of 30 to 60 years in Spain, which limits generalisability. The behavioural intervention was necessarily unblinded, an unavoidable feature of dietary-timing trials that can bias self-reported questionnaires. Can I use this with my patients? Yes, in a specific way: for a motivated adult with overweight or obesity considering time-restricted eating for weight management, this evidence supports counselling that the approach is unlikely to worsen sleep, mood, or quality of life, while setting the honest expectation that it will not improve them either. I would welcome longer trials powered prospectively for these patient-centred outcomes.
References
Clavero-Jimeno A, Dote-Montero M, Migueles JH, et al. Time-restricted eating and sleep, mood, and quality of life in adults with overweight or obesity: a secondary analysis of a randomized clinical trial. JAMA Netw Open. 2025;8(6):e2517268. doi:10.1001/jamanetworkopen.2025.17268