Characteristics of each group at baseline by frequency of breakfast intake
| Variable | Frequency of breakfast intake at baseline | Est | P value | ||
| <4 times a week (n=42) | ≥4 and <7 times a week (n=52) | 7 times a week (n=639) | |||
| Frequency of breakfast intake (times a week) | 1.9±1.5 | 5.5±0.5 | 7.0±0.0 | ||
| Age (years) | 53.0±8.7 | 53.9±9.7 | 58.4±8.3 | 5.13 | <0.001 |
| Male gender (%) | 32 (76.2) | 31 (59.6) | 397 (62.5) | 1.36 | 0.17 |
| Morningness-Eveningness Questionnaire score | 51.0±7.0 | 52.3±7.3 | 58.2±7.0 | 8.05 | <0.001 |
| Pittsburgh Sleep Quality Index score | 6.0±3.2 | 6.1±2.6 | 5.0±3.0 | −2.94 | 0.003 |
| Sleep duration (hours) | 6.4±1.2 | 6.3±1.2 | 6.5±1.2 | 1.03 | 0.3 |
| Beck Depression Inventory score | 13.8±7.7 | 11.9±7.4 | 9.5±7.6 | −4.10 | <0.001 |
| Caloric intake (kcal/day) | 1712±507 | 1695±802 | 1722±570 | 0.23 | 0.82 |
| Carbohydrate intake (g/day) | 219±71 | 214±90 | 227±75 | 1.09 | 0.28 |
| Fat intake (g/day) | 47±19 | 49±31 | 49±21 | 0.51 | 0.61 |
| Protein intake (g/day) | 61±24 | 64±39 | 67±29 | 1.53 | 0.13 |
| Physical activity (METs·h/week) | 34.2±54.1 | 32.2±46.6 | 45.3±76.7 | 1.34 | 0.18 |
| Smoker (current/former/never) | 13/16/13 (31.0/38.1/31.0) | 16/11/25 (30.8/21.2/48.1) | 148/184/307 (23.2/28.8/48.0) | 1.91 | 0.06 |
| Alcohol consumption (g/day) | 20.2±27.4 | 17.1±29.2 | 11.5±20.3 | −3.00 | 0.003 |
| Worker (yes) | 31 (73.8) | 46 (88.5) | 461 (72.1) | −1.32 | 0.19 |
| Shift worker (yes) | 4 (9.5) | 6 (11.5) | 68 (10.6) | 0.10 | 0.91 |
| Regular snacking (time a week) | 0.6±0.6 | 0.8±0.7 | 0.7±0.7 | 0.41 | 0.69 |
| Late evening snacks (yes) | 19 (45.2) | 22 (42.3) | 248 (38.8) | −0.93 | 0.35 |
| Time from last meal to bedtime (hours) | 3.1±1.3 | 3.7±1.7 | 3.4±1.6 | 0.56 | 0.58 |
| Time of dinner (hour) | 19.8±1.2 | 19.8±1.2 | 19.2±1.1 | −4.75 | <0.001 |
| Eating out and/or eating ready-made meals at home for dinner (almost never/1 to 2/3 to 4/5 or more times a week | 16 (38.1)/13 (31.0)/10 (23.8)/3 (7.1) | 16 (30.8)/28 (53.8)/4 (7.7)/4 (7.7) | 370 (57.9)/209 (32.7)/35 (5.5)/25 (3.9) | −4.56 | <0.001 |
| Excessive daytime sleepiness (yes) | 16 (38.1) | 18 (34.6) | 199 (31.2) | −1.02 | 0.31 |
| Estimated duration of diabetes (years) | 7.2±4.4 | 9.4±6.8 | 10.1±7.3 | 2.40 | 0.02 |
| Body mass index (kg/m2) | 26.6±4.6 | 25.9±5.0 | 24.4±3.9 | −4.13 | <0.001 |
| Diabetic retinopathy (number) (%) | 13 (31.0) | 21 (40.4) | 232 (36.8) | 0.43 | 0.67 |
| Diabetic nephropathy (number) (%) Normoalbuminuria/microalbuminuria/macroalbuminuria | 29 (70.7)/10 (24.4)/2 (4.9) | 36 (70.6)/12 (23.5)/3 (5.9) | 200 (31.5)/507 (80.6)/101 (16.1) | −2.03 | 0.04 |
| Diabetic neuropathy (number) (%) | 6 (14.3) | 11 (21.2) | 175 (27.6) | 2.07 | 0.04 |
| Antidiabetes drugs (yes) | 37 (88.1) | 44 (84.6) | 541 (85.3) | −0.37 | 0.71 |
| Insulin therapy (yes) | 3 (7.1) | 7 (13.5) | 69 (10.9) | 0.40 | 0.69 |
| Antihypertension drugs (yes) | 22 (52.4) | 23 (44.2) | 302 (47.6) | −0.31 | 0.75 |
| Antihyperlipidemia drugs (yes) | 25 (59.5) | 34 (65.4) | 384 (60.6) | −0.18 | 0.86 |
| Antiplatelet drugs (yes) | 0 (0.0) | 2 (3.8) | 22 (3.5) | 0.96 | 0.34 |
| Sleep apnea syndrome (yes) | 2 (4.8) | 0 (0.0) | 23 (3.6) | 0.25 | 0.80 |
Data are mean±SD or number (proportion) of patients. Est is the regression coefficient for linear trends across quintiles and is based on linear regression analysis for continuous variables or logistic regression analysis for categorical variables.