8. Results of cohort studies: waist circumference.
|
Study ID; mean age at baseline; analysis |
Outcome | Outcome units | Time point (year) | Exposure | Exposure unit | Results of association (all reported values) |
Direction;a energy intake adjusted? (yes/no) |
Matched groups or adjusted for (or both) | |
| Waist circumference at > 1to 2 years: 1 cohort study; 1 analysis (n = 310) in boys and girls aged 13 years | |||||||||
|
Setayeshgar 2017 12.5 years; regression |
WC | cm | 2 | Total fat intake (single 24‐hour recall at baseline) | per 10 g | n overall = 310, regression result. B = 0.31 (95% CI 0.08 to 0.58), P ≤ 0.05. After 2 years, for every 10‐g increase in the total fat intake of children, WC will increase by 0.31 cm. |
+ No |
Age, gender, baseline BMI z‐score, baseline WC, moderate to vigorous physical activity, vegetables and fruit, fibre, milk, sodium and added sugar. | |
| Waist circumference at > 2to 5 years: 1 cohort study; 4 analyses (n = 2680) in boys and girls aged 14 years | |||||||||
|
Appannah 2015 14 years; regression and OR higher vs lower dietary pattern z‐score |
WC | WC ≥ 80 cm, odds | 3 | Energy‐dense, high‐fat and low‐fibre dietary patternb (single FFQ at baseline and 3 years) | z‐score | n boys = 697, regression result. OR = 1 (95% CI 0.82 to 1.22). After 3 years, the ratio of odds that WC is ≥ 80 cm is the same in boys with higher dietary pattern z‐scores compared to the odds in boys with lower dietary pattern z‐scores, during the period from 14 to 17 years of age. |
0 NA; exposure includes energy intake |
Age, dietary misreporting, physical fitness, smoking and BMI z‐score. | |
|
Appannah 2015 14 years; regression and OR higher vs lower dietary pattern z‐score |
WC | WC ≥ 80 cm, odds | 3 | Energy‐dense, high‐fat and low‐fibre dietary patternb (single FFQ at baseline and 3 years) | z‐score | n girls = 643, regression result. OR = 1.28 (95% CI 1.00 to 1.63). After 3 years, the ratio of odds that WC is ≥ 80 cm is 1.28 greater in girls with higher dietary pattern z‐scores compared to the odds in girls with lower dietary pattern z‐scores, during the period from 14 to 17 years of age. |
+ NA; exposure includes energy intake |
Age, dietary misreporting, physical fitness, smoking and BMI z‐score. | |
|
Appannah 2015 14 years; regression |
WC | z‐score | 3 | Energy‐dense, high‐fat and low‐fibre dietary patternb (single FFQ at baseline and 3 years) | z‐score | n boys = 697, regression result. β = 0.003 (95% CI ‐0.02 to 0.03). After 3 years, for every 1 unit increase in z‐score of the energy‐dense, high‐fat and low‐fibre dietary pattern of boys, WC will increase by 0.003 z‐scores. |
+ NA; exposure includes energy intake |
Age, dietary misreporting, physical fitness, smoking and BMI z‐score. | |
|
Appannah 2015 14 years; regression |
WC | z‐score | 3 | Energy‐dense, high‐fat and low‐fibre dietary patternb (single FFQ at baseline and 3 years) | z‐score | n girls = 643, regression result. β = 0.04 (95% CI 0.01 to 0.07). After 3 years, for every 1 unit increase in z‐score of the energy‐dense, high‐fat and low‐fibre dietary pattern of girls, WC will increase by 0.04 z‐scores. |
+ NA; exposure includes energy intake |
Age, dietary misreporting, physical fitness, smoking and BMI z‐score. | |
| Waist circumference at > 5to 10 years: 1 cohort study; 2 analyses (n = 512) in girls aged 10 years | |||||||||
|
Morrison 2008 10.1 years; regression |
WC | cm, 10‐years change |
10 | Total fat intake (single 3‐day dietary records at 1, 2, 3, 4, 5, 7, 8 and 10 years) × baseline IR | %TE | n white girls = 236. B = 0.053, SE 0.0065, P < 0.0001. After 10 years, for every 1% increase in energy intake from total fat in white girls, WC will increase by 0.053 cm. |
+ Yes |
Age, WC, IR, and maturation stage at baseline; change in IR over 10‐years follow‐up; percentage of calories from protein, fat, and CHO (mean of interviews) during 10‐years follow‐up; and interaction terms (nutrients × baseline IR). | |
|
Morrison 2008 10.1 years; regression |
WC | cm, 10‐years change |
10 | Total fat intake (single 3‐day dietary records at 1, 2, 3, 4, 5, 7, 8 and 10 years) × baseline IR | %TE | n black girls = 276. B = 0.028, SE 0.0056, P < 0.0001. After 10 years, for every 1% increase in energy intake from total fat in black girls, WC will increase by 0.028 cm. |
+ Yes |
"Age, waist circumference, IR, and maturation stage at baseline; change in IR over 10‐y follow‐up; percentage of calories from protein, fat, and CHO (mean of interviews) during 10‐y follow‐up; and interaction terms (nutrients baseline IR)." | |
aDirection refers to whether there was a positive (+: exposure and outcome moved in the same direction), inverse/negative (‐: exposure and outcome moved in opposite directions) or zero (0: no association) between total fat intake and the outcome.
b"Energy dense, high fat, low fibre" dietary pattern reflected high intakes of processed meat, chocolate and confectionery, low‐fibre bread, crisps and savoury snacks, fried and roasted potatoes, the high intake of these foods increase the individual’s dietary pattern z‐score.
%TE: percentage of total energy; B: unstandardised beta‐coefficient; β: standardised beta‐coefficient; BMI: body mass index; CHO: carbohydrate; CI: confidence interval; FFQ: Food Frequency Questionnaire; IR: insulin resistance; n: number of participants; NA: not applicable; OR: odds ratio; WC: waist circumference.