Table 3.
Associations between meal frequency and diet quality scores in 639 Japanese adults aged 20–81 years*
(Mean values and standard deviations; mean values with their standard errors; median values and ranges)
| Mean | sd | Meal frequency (participant identified)† | Meal frequency (time of day)‡ | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Categorical | Categorical | |||||||||||||||||||
| C1 (n 123) | C2 (n 516) | P | Continuous | C1 (n 220) | C2 (n 196) | C3 (n 223) | P for trend | Continuous | ||||||||||||
| Mean | se | Mean | se | β § | se | P | Mean | se | Mean | se | Mean | se | β § | se | P | |||||
| Meal frequency (times/d)‖ | 2·75 (1·5–2·75) | 3 (3) | 2·75 (0·5–3) | 3·5 (3·25–3·75) | 4·5 (4–6·75) | |||||||||||||||
| HEI-2015¶ | 52·1 | 7·4 | 50·7 | 0·6 | 52·5 | 0·3 | 0·01 | 3·6 | 1·5 | 0·01 | 50·8 | 0·5 | 52·6 | 0·5 | 53·0 | 0·4 | 0·001 | 1·3 | 0·3 | <0·0001 |
| Total fruits | 1·53 | 1·41 | 1·40 | 0·12 | 1·56 | 0·06 | 0·21 | 0·06 | 0·28 | 0·84 | 1·37 | 0·09 | 1·65 | 0·09 | 1·58 | 0·09 | 0·09 | 0·11 | 0·06 | 0·052 |
| Whole fruits | 2·33 | 1·90 | 2·02 | 0·16 | 2·40 | 0·07 | 0·03 | 0·55 | 0·37 | 0·14 | 2·08 | 0·11 | 2·54 | 0·12 | 2·39 | 0·11 | 0·06 | 0·18 | 0·07 | 0·02 |
| Total vegetables | 4·59 | 0·79 | 4·41 | 0·07 | 4·63 | 0·03 | 0·006 | 0·65 | 0·17 | 0·0001 | 4·47 | 0·05 | 4·62 | 0·05 | 4·68 | 0·05 | 0·005 | 0·13 | 0·03 | 0·0002 |
| Greens and beans | 3·43 | 1·74 | 3·26 | 0·15 | 3·47 | 0·07 | 0·23 | 1·02 | 0·36 | 0·005 | 3·09 | 0·11 | 3·69 | 0·12 | 3·53 | 0·11 | 0·006 | 0·24 | 0·07 | 0·0009 |
| Whole grains | 0·63 | 1·59 | 0·75 | 0·15 | 0·60 | 0·07 | 0·38 | –0·09 | 0·36 | 0·80 | 0·44 | 0·11 | 0·70 | 0·11 | 0·74 | 0·11 | 0·06 | 0·17 | 0·07 | 0·02 |
| Dairy products | 2·08 | 1·68 | 1·75 | 0·15 | 2·15 | 0·07 | 0·02 | 0·16 | 0·36 | 0·65 | 1·96 | 0·11 | 2·06 | 0·12 | 2·21 | 0·11 | 0·11 | 0·07 | 0·07 | 0·37 |
| Total protein foods | 4·75 | 0·57 | 4·67 | 0·05 | 4·77 | 0·02 | 0·11 | 0·36 | 0·12 | 0·004 | 4·69 | 0·04 | 4·80 | 0·04 | 4·76 | 0·04 | 0·19 | 0·06 | 0·03 | 0·02 |
| Seafood and plant proteins | 4·78 | 0·72 | 4·74 | 0·07 | 4·79 | 0·03 | 0·54 | 0·07 | 0·16 | 0·66 | 4·70 | 0·05 | 4·82 | 0·05 | 4·82 | 0·05 | 0·08 | 0·09 | 0·03 | 0·004 |
| Fatty acids** | 6·31 | 2·58 | 6·11 | 0·24 | 6·36 | 0·11 | 0·36 | 0·30 | 0·57 | 0·60 | 6·51 | 0·17 | 5·95 | 0·18 | 6·42 | 0·17 | 0·75 | 0·01 | 0·11 | 0·94 |
| Refined grains | 1·40 | 2·14 | 1·46 | 0·20 | 1·38 | 0·09 | 0·73 | –0·23 | 0·48 | 0·63 | 1·31 | 0·15 | 1·49 | 0·15 | 1·39 | 0·14 | 0·72 | 0·04 | 0·10 | 0·67 |
| Sodium | 1·96 | 2·60 | 2·08 | 0·23 | 1·93 | 0·11 | 0·59 | –0·51 | 0·56 | 0·36 | 1·87 | 0·17 | 1·99 | 0·18 | 2·03 | 0·17 | 0·50 | 0·09 | 0·11 | 0·41 |
| Added sugars | 9·42 | 1·13 | 9·17 | 0·10 | 9·48 | 0·05 | 0·009 | 1·06 | 0·24 | <0·0001 | 9·43 | 0·08 | 9·46 | 0·08 | 9·36 | 0·07 | 0·52 | 0·03 | 0·05 | 0·52 |
| Saturated fats | 8·93 | 1·65 | 8·85 | 0·15 | 8·95 | 0·07 | 0·57 | 0·20 | 0·35 | 0·57 | 8·93 | 0·11 | 8·78 | 0·11 | 9·06 | 0·11 | 0·38 | 0·08 | 0·07 | 0·28 |
| NRF9.3†† | 667 | 106 | 639 | 9 | 674 | 4 | 0·0006 | 118 | 21 | <0·0001 | 652 | 7 | 680 | 7 | 671 | 7 | 0·054 | 16·0 | 4·3 | 0·0002 |
| Protein | 100·0 | 0·4 | 99·9 | 0·0 | 100·0 | 0·0 | 0·16 | 0·1 | 0·1 | 0·20 | 99·9 | 0·0 | 100·0 | 0·0 | 100·0 | 0·0 | 0·04 | 0·0 | 0·0 | 0·16 |
| Dietary fibre | 77·5 | 16·7 | 75·0 | 1·5 | 78·1 | 0·7 | 0·06 | 8·8 | 3·5 | 0·01 | 75·2 | 1·1 | 79·6 | 1·1 | 77·9 | 1·1 | 0·09 | 1·7 | 0·7 | 0·02 |
| Vitamin A | 68·1 | 21·7 | 68·3 | 2·0 | 68·0 | 0·9 | 0·92 | 8·6 | 4·7 | 0·06 | 66·6 | 1·4 | 70·1 | 1·5 | 67·8 | 1·4 | 0·58 | 1·1 | 0·9 | 0·25 |
| Vitamin C | 89·9 | 16·6 | 88·7 | 1·5 | 90·2 | 0·7 | 0·40 | 11·4 | 3·6 | 0·001 | 87·8 | 1·1 | 91·3 | 1·1 | 90·8 | 1·1 | 0·06 | 2·0 | 0·7 | 0·005 |
| Vitamin D | 86·4 | 22·5 | 83·3 | 2·0 | 87·1 | 1·0 | 0·09 | 14·0 | 4·8 | 0·004 | 83·9 | 1·5 | 89·0 | 1·5 | 86·5 | 1·5 | 0·23 | 2·0 | 1·0 | 0·04 |
| Ca | 79·9 | 18·1 | 75·3 | 1·6 | 81·0 | 0·8 | 0·001 | 10·0 | 3·8 | 0·009 | 76·4 | 1·2 | 81·3 | 1·2 | 82·2 | 1·2 | 0·0006 | 3·1 | 0·8 | <0·0001 |
| Fe | 92·1 | 13·8 | 90·6 | 1·0 | 92·4 | 0·5 | 0·12 | 4·6 | 2·5 | 0·06 | 91·7 | 0·8 | 92·6 | 0·8 | 92·0 | 0·8 | 0·77 | 0·6 | 0·5 | 0·25 |
| K | 92·5 | 10·7 | 90·4 | 0·9 | 93·0 | 0·4 | 0·01 | 8·4 | 2·2 | 0·0002 | 90·2 | 0·7 | 93·8 | 0·7 | 93·7 | 0·7 | 0·0004 | 1·9 | 0·4 | <0·0001 |
| Mg | 90·4 | 11·9 | 87·9 | 1·0 | 91·0 | 0·5 | 0·008 | 8·5 | 2·5 | 0·0006 | 88·0 | 0·8 | 92·3 | 0·8 | 91·1 | 0·7 | 0·006 | 1·8 | 0·5 | 0·0003 |
| Added sugars | 36·9 | 52·4 | 47·5 | 4·8 | 34·4 | 2·2 | 0·02 | –46·4 | 11·2 | <0·0001 | 34·5 | 3·5 | 36·3 | 3·6 | 39·9 | 3·4 | 0·27 | –0·4 | 2·3 | 0·88 |
| Saturated fats | 20·5 | 23·3 | 21·7 | 2·1 | 20·2 | 1·0 | 0·53 | –3·0 | 5·0 | 0·55 | 20·6 | 1·5 | 23·0 | 1·6 | 18·3 | 1·5 | 0·27 | –1·3 | 1·0 | 0·19 |
| Na | 51·9 | 34·0 | 51·1 | 3·0 | 52·1 | 1·4 | 0·76 | 5·3 | 7·2 | 0·46 | 52·2 | 2·2 | 50·5 | 2·3 | 52·8 | 2·2 | 0·85 | –0·1 | 1·4 | 0·94 |
C, category; HEI-2015, Healthy Eating Index-2015; NRF9.3, Nutrient-Rich Food Index 9.3.
For analyses on the associations between meal frequency and diet quality scores, the meal frequency variable was treated as a categorical variable or a continuous variable based on the general linear model, with adjustment for sex, age group, weight status, dietary reporting status, survey year and snack frequency based on the same definition.
For the participant-identified definition, eating occasions recorded in the sections of breakfast, lunch and dinner in the food diary were considered meals, while eating occasions recorded in the snack section were considered snacks. For multiple entries of eating occasions into a section of breakfast, lunch or dinner (ten cases), however, the first eating occasion was considered a meal, and the following eating occasions were considered snacks.
For the time-of-day definition, meals were defined as eating occasions whose start time was within select time periods of the day (06.00–10.00, 12.00–15.00 and 18.00–21.00 hours), and any eating occasions starting outside of these time periods were considered snacks.
Regression coefficients mean the change of diet quality scores with one additional eating occasion per d.
Values are medians (ranges).
Calculated as the sum of all components scores. A maximum score is 100. A maximum score for each component is as follows: 5 for total fruits, whole fruits, total vegetables, greens and beans, total protein foods and seafood and plant proteins and 10 for whole grains, dairy products, fatty acids, refined grains, Na, added sugars and saturated fats. A higher score indicates a higher diet quality (i.e. a lower intake for refined grains, Na, added sugars and saturated fats components and a higher intake for other components).
Defined as the ratio of the sum of PUFA and MUFA to SFA.
Calculated as the sum of scores for nine nutrients to encourage (i.e. protein, dietary fibre, vitamins A, C and D, Ca, Fe, K and Mg) minus the sum of scores for three nutrients to limit (i.e. added sugars, saturated fats and Na). A maximum score is 900. For each component, a maximum score is 100, except for added sugars, saturated fats and Na components, for which a maximum score is infinite depending on the intake level. A higher score indicates a higher diet quality, except for added sugars, saturated fats and Na components, for which a higher score indicates an unfavourable dietary intake (i.e. higher intakes of added sugars, saturated fats and Na).