Table 1.
Characteristics of included studies.
| References | Participants† | Exposure† | Assessment§ | Primary outcome†‡ |
|---|---|---|---|---|
| Yamaguchi et al. (26), Japan | CDOA (n = 1,101) 71.6 ± 4.8 years | Eating A/T (breakfast/dinner) | FI: FFQ PS: K6 scale | • Alone × Low n-3 PUFA (vs. Social × High): 2.18 (1.05–4.55) • K6 score ≥5: 30.0% (303/1011) |
| Tani et al. (7), Japan | CDOA (n = 82,364) ≥65 years | Eating A/T | FI: SRQ | • A/T in males: Low vegetable/fruit. 1.59 (1.47–1.72), underweight 1.22 (1.02–1.45) |
| Pinheiro et al. (27), Brazil | CDOA (n = 8,336) ≥60 years | Living A/T | FI: R24h | • Living A/T: Low solid fats 0.76 (0.66–0.88); Low leafy veg 0.72 (0.62–0.83) |
| Kimura et al. (28), Japan | CDOA (n = 856) 76.6 ± 7.8 years | Eating A/T | FI: FDSK-11 PS: GDS-15 | A/T: • FDSK-11: 9.9 ± 1.3 vs. 10.2 ± 1.3 (P = 0.002) • GDS-15: 5.7 ± 4.3 vs. 4.4 ± 3.8 (P < 0.001) • BMI (men): Alone < Together (P < 0.05) |
| Björnwall et al. (29), Sweden | CDOA (n = 695) 70–75 years | Eating A/T | FI: food index; R24h | • A/T: Low vegetable intake 0.68 (0.48–0.95); No difference in food index 1.03 (0.72–1.47) |
| Kwon et al. (30), South Korea | CDOA (n = 4,069) ≥65 years | Eating alone (vs. together 3/d) | FI: R24h; FFQ PS: PHQ-9; EQ-5 | • A/T: PHQ-9 ≥10, 2.464 (1.527–3.975); EQ-5, 0.773 vs. 0.820 |
| Minagawa-Watanabe et al. (31), Japan | CDOA (n = 993) 64–65 years | Dining with ≥2 companions (vs. alone) | FI: FFQ PS: GDS-15 | • Alone (Ref) vs. ≥2 companions: β for Energy 143.85 (30.05–257.65), Protein 6.32 (1.05–11.59), Fat 6.78 (2.44–11.12), Carb 17.43 (1.48–33.37); GDS 28.4% vs. 24.3% (P = 0.01) |
| Ishikawa et al. (32), Japan | CDOA (n = 2,196) ≥65 years | Eating together (vs. alone < 1/month | FI: FDI PS: KYC | • A/T: Lower food diversity 46.7% vs. 37.1%(P < 0.001); Lower subjective health 33.3% vs. 13.5% (P < 0.001); Non-frail (Men): 58.2% vs. 85.0%; OR 0.48 (0.35–0.68) |
| Yokoro et al. (33), Japan | CDOA (n = 1,780) 73.9 ± 6.0 years | Living A/T | FI: DVS PS: FCI-5 | • A/T in men: Frailty 1.8 ± 1.2 vs. 1.3 ± 1.1 (P < 0.001); Dietary variety 2.8 ± 2.0 vs. 3.8 ± 2.1 (P < 0.001) |
| Ishida and Ishida (34), Japan | CDOA (n = 1,336) ≥65 years | Eating A/T | FI: a 5-item questionnaire | • Single men (vs. women): Y1, −0.213; Y2, −0.352; Y3, −0.187; Y4, −0.189; Y5, −0.160 |
| Locher et al. (35), USA | CDOA (n = 50) ≥60 years | Eating A/T | FI: R24h | • A/T: Caloric intake/meal −114.0 kcal (P = 0.009) |
| Takiguchi et al. (36), Japan | CDOA (n = 51) ≥65 years | Eating A/T, women only | FI: DRs2d | • A/T in Women: Fresh fruit 151.2 ± 81.6 vs. 97.7 ± 62.9 g (P < 0.05) |
| Prothro et al. (37), USA | CDOA (n = 95) ≥65 years | Living A/T | FI: DRs2d; R24h | • A/T: PTER 75.0 ± 27.8 vs. 74.5 ± 22.8 (NS); Carb (% kcal) t = 2.72 (P < 0.01); Fat (% kcal) t = −2.65 (P < 0.01) |
| Son et al. (38), South Korea | CDOA (n = 3,729) ≥65 years subgroup | Eating alone (vs. together 3/d) | PS: MHS | • Alone × High depression. (vs. Social × Low depression.): Men 1.72 (1.27–2.34); Women 1.58 (1.28–1.95) |
| Kang et al. (39), South Korea | CDOA (n = 4,959) 72.9 ± 0.1 years | Eating alone (vs. together 3/d) | PS: SRQ | • Alone × High depression/anxiety (vs. Family 3/d × Low depression/anxiety): aOR 0.72 (0.58–0.89) |
| Kuroda et al. (40), Japan | CDOA (n = 1,856) ≥65 years | Eating A/T | PS: GDS-15 | • Alone × High depressive symptoms (vs. Together × Low): 2.96 (1.8–5.0) |
| Kantilafti et al. (41), Cyprus | CDOA (n = 248) median 72 years | Eating A/T | FI: MNA PS: GDS-15 | • Alone × High depression (vs. Together × Low): aOR 2.00 (1.00–3.99) |
| Wang et al. (42), China | CDOA (n = 7,968) median 67 years | Eating A/T | PS: PHQ-9 | • A/T: Depressive symptoms 12.9% vs. 4.5%−9.4% (P < 0.001) |
| Kushida et al. (43), Japan | CDOA (n = 2,764) ≥65 years | Eating alone at all meals (vs. Never) | PS: GDS-5 | • Alone × High depression (vs. Together × Low): Breakfast 1.71 (1.40–2.09); Lunch 1.43 (1.17–1.76); Dinner 2.13 (1.57–2.90) |
| Sakurai et al. (9), Japan | CDOA (n = 710) 73.8 ± 5.5 years | Eating alone (vs. Together ≥1/d) | PS: SDS | • A/T: Higher SDS score, main effect significant (P < 0.001) |
| Moon et al. (21), South Korea | CDOA (n = 2,702) ≥60 years | Eating A/T (≤ 2/d vs. >2/d) | PS: SGDS-K | • Alone × High depression (vs. Together × Low) in Robust: Living together 1.60 (1.21–2.00); Living alone 1.94 (1.46–2.56) |
†
CDOA, community-dwelling older adults. The age of the study participants is described using mean ± standard deviation, median, or range as appropriate. A/T, alone vs. together.
§
FI, food intake; PS, psychological status. DRs2d, 2-day dietary records; DVS, dietary variety score; EQ-5D, Euro Quality of Life five-dimension; FCI-5, 5-item frailty screening index; FDI, food diversity index; FDSK-11, 11-item food diversity score Kyoto; FFQ, food frequency questionnaire; GDS-15, 15-item geriatric depression scale; GDS-5, Japanese version 5-item geriatric depression scale; K6 scale, Kessler 6 scale; KYC, Kaigo-Yobo checklist; MHS, mental health survey; MNA, mini nutritional assessment; PHQ-9, patient health questionnaire-9; R24h, 24-h food recall; SDS, Zung self-rating depression scale; SGDS-K, Korean version of the 15-item geriatric depression scale; SRQ, self-reported questionnaires.
‡
Reported as odds ratio or mean difference with 95%CI as appropriate.