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. 2018 Jul 5;2018(7):CD012960. doi: 10.1002/14651858.CD012960.pub2
Total fat intake ≤ 30% of total energy compared to usual fat intake for bodyweight in children (RCTs)a
Patient or population: boys and girls aged 24 months to 18 years
Setting: paediatric practices, schools and health maintenance organisations in high‐income countries
Intervention: lower total fat intake ≤ 30%TE
Comparison: usual or modified fat intake
Outcomes
(at time point ranges where data were reported)
No of participants
(No of studies)
Illustrated comparative effect (95% CI) Quality What happens
Usual fat intake1 Effect difference with total fat ≤ 30% of total energy2
Weight‐for‐age z‐score
 Follow‐up: 6 months 149
(1 RCT)
The mean weight‐for‐age z‐score in control group was 0.26 MD 0.14 lower
 (0.46 lower to 0.18 higher) ⊕⊝⊝⊝
 Very low3,4,5,6 We were uncertain whether lower total fat intake (≤ 30%TE) had an effect on weight‐for‐age in children over a 12‐month period (1 study).
Follow‐up: range 6 to 12 months 151
(1 RCT)
The mean weight‐for‐age z‐score in control group was 0.29 MD 0.18 lower
 (0.51 lower to 0.15 higher) ⊕⊝⊝⊝
 Very low3,4,5,6
Weight (kg)
 Follow‐up: range 6 to 12 months 620
(1 RCT)
The mean weight (kg) in control group was 38.2 MD 0.5 lower
 (1.78 lower to 0.78 higher) ⊕⊕⊝⊝
 Low4,5,7,8 Lower total fat intake (≤ 30%TE) may have made little or no difference to weight in children over a 5‐year period (1 study).
Follow‐up: range 2 to 5 years 612
(1 RCT)
The mean weight (kg) in control group was 49.5 MD 0.6 lower
 (2.39 lower to 1.19 higher) ⊕⊕⊝⊝
 Low4,5,7,8
BMI (kg/m2)
 Follow‐up: range 6 to 12 months 620
(1 RCT)
The mean BMI (kg/m2) in control group was 18.5 MD 0.3 lower
 (0.75 lower to 0.15 higher) ⊕⊕⊝⊝
 Low4,5,7,8 Lower total fat intake (≤ 30%TE) may have made little or no difference to BMI in children over a 1‐year period (1 study).
Follow‐up: range 1 to 2 years 191
(1 RCT)
The mean BMI (kg/m2) in control group was 24.8 MD 1.5 lower
 (2.45 lower to 0.55 lower) ⊕⊕⊕⊝
 Moderate4,9,10 Lower total fat intake (≤ 30%TE) probably reduced BMI in children over a period of 1 to 2 years (1 study).
Follow‐up: range 2 to 5 years 541
(1 RCT)
The mean BMI (kg/m2) in control group was 21.7 MD 0 
 (0.63 lower to 0.63 higher) ⊕⊕⊝⊝
 Low4,5,7,8 Lower total fat intake (≤ 30%TE) may have made little or no difference to BMI in children over a 2 to 5‐year period (1 study).
Follow‐up: > 5 years 576
(1 RCT)
The mean BMI (kg/m2) in control group was 23.0 MD 0.1 lower
 (0.75 lower to 0.55 higher) ⊕⊕⊝⊝
 Low4,5,7,8
Total cholesterol (mmol/L)
 Follow‐up: range 6 to 12 months 618
(1 RCT)
The mean total cholesterol (mmol/L) in control group was 5.1 MD 0.15 lower
 (0.24 lower to 0.06 lower) ⊕⊕⊕⊝
 Moderate4,5,7,11 Total fat intake ≤ 30%TE probably slightly reduced total cholesterol in children over a 12‐month period (1 study).
Follow‐up: range 2 to 5 years 522
(1 RCT)
The mean total cholesterol (mmol/L) in control group was 4.6 MD 0.06 lower
 (0.17 lower to 0.05 higher) ⊕⊕⊝⊝
 Low4,5,7,8 Lower total fat intake (≤ 30%TE) may have made little or no difference to total cholesterol in children over a 2 to 5‐year period and a > 5‐year period (1 study).
Follow‐up: > 5 years 548
(1 RCT)
The mean total cholesterol (mmol/L) in control group was 4.66 MD 0.02 lower
 (0.13 lower to 0.09 higher) ⊕⊕⊝⊝
 Low4,5,7,8
LDL‐C (mmol/L)
 Follow‐up: range 6 to 12 months 618
(1 RCT)
The mean LDL‐C (mmol/L) in control group was 3.29 MD 0.12 lower
 (0.2 lower to 0.04 lower) ⊕⊕⊕⊝
 Moderate4,5,7,11 Lower total fat intake (≤ 30%TE) probably reduced LDL‐C in children over a 12‐month period (1 study) and over a 2 to 5‐year period (1 study).
Follow‐up: range 2 to 5 years 623
(1 RCT)
The mean LDL‐C (mmol/L) in control group was 3.07 MD 0.09 lower
 (0.17 lower to 0.01 lower) ⊕⊕⊕⊝
 Moderate4,5,7,11
Follow‐up: > 5 years 548
(1 RCT)
The mean LDL‐C (mmol/L) in control group was 3.00 MD 0.01 higher
 (0.01 lower to 0.03 higher) ⊕⊕⊕⊝
 Moderate4,5,7,12 Lower total fat intake (≤ 30%TE) probably made little or no difference to LDL‐C in children over a > 5‐year period (1 study).
HDL‐C (mmol/L)
 Follow‐up: range 6 to 12 months 618
(1 RCT)
The mean HDL‐C (mmol/L) in control group was 1.47 MD 0.03 lower
 (0.08 lower to 0.02 higher) ⊕⊕⊕⊝
 Moderate4,5,7,12 Lower total fat intake (≤ 30%TE) probably made little or no difference to HDL‐C in children over a period of up to and > 5 years (1 study).
Follow‐up: range 2 to 5 years 522
(1 RCT)
The mean HDL‐C (mmol/L) in control group was 1.32 MD 0.01 lower
 (0.06 lower to 0.04 higher) ⊕⊕⊕⊝
 Moderate4,5,7,12
Follow‐up: > 5 years 548
(1 RCT)
The mean HDL‐C (mmol/L) in control group was 1.27 MD 0.02 higher
 (0.03 lower to 0.07 higher) ⊕⊕⊕⊝
 Moderate4,5,7,12
Triglycerides (mmol/L)
 Follow‐up: range 6 to 12 months 618
(1 RCT)
The mean triglycerides (mmol/L) in control group was 0.98 MD 0.01 lower
 (0.08 lower to 0.06 higher) ⊕⊕⊕⊝
 Moderate4,5,7,12 Lower total fat intake (≤ 30%TE) probably made little or no difference to triglycerides in children over a period of 6 to 12 months (1 study).
Lower total fat intake (≤30%TE) may make little or no difference to triglycerides in children over a period > 2 years (1 study).
Follow‐up: range 2 to 5 years 522
(1 RCT)
The mean triglycerides (mmol/L) in control group was 1.07 MD 0.06 higher
 (0.04 lower to 0.16 higher) ⊕⊕⊝⊝
 Low4,5,7,8
Follow‐up: > 5 years 548
(1 RCT)
The mean triglycerides (mmol/L) in control group was 1.1 MD 0.03 higher
 (0.06 lower to 0.12 higher) ⊕⊕⊝⊝
 Low4,5,7,8
Height‐for‐age z‐score
 Follow‐up: 6 months 149
(1 RCT)
The mean height‐for‐age z‐score in control group was 0.03 MD 0.02 lower
 (0.06 lower to 0.02 higher) ⊕⊝⊝⊝
 Very low3,4,5,6 We were uncertain whether lower total fat intake (≤ 30%TE) reduced height‐for‐age in children over a 12‐month period (1 study).
Follow‐up: range 6 to 12 months 151
(1 RCT)
The mean height‐for‐age z‐score in control group was 0.05 MD 0.05 lower
 (0.08 lower to 0.02 lower) ⊕⊝⊝⊝
 Very low3,4,5,13
Height (cm)
 Follow‐up: range 6 to 12 months 642
(1 RCT)
The mean height (cm) in control group was 143.1 MD 0
 (1.11 lower to 1.11 higher) ⊕⊕⊝⊝
 Low4,5,7,8 Lower total fat intake (≤ 30%TE) may have made little or no difference to height in children over a period of 5 years (1 study).
Follow‐up: range 2 to 5 years 540
(1 RCT)
The mean height (cm) in control group was 167.4 MD 0.10 lower
 (1.54 lower to 1.34 higher) ⊕⊕⊝⊝
 Low4,5,7,8
Follow‐up: > 5 years 577
(1 RCT)
The mean height (cm) in control group was 171.4 MD 0.60 lower
 (2.06 lower to 0.86 higher) ⊕⊕⊝⊝
 Low4,5,7,8
%TE: percentage of total energy; BMI: body mass index; CI: confidence interval; HDL‐C: high‐density lipoprotein cholesterol; LDL‐C: low‐density lipoprotein cholesterol; MD: mean difference; RCT: randomised controlled trial.
aNotes: For all outcomes, there were too few studies to assess publication bias.
No studies looked at weight‐for‐age at > 12 months, weight at 1 to 2 years and > 5 years, BMI at 6 months, total cholesterol at 6 months and 1 to 2 years, LDL‐C at 6 months and 1 to 2 years, HDL‐C at 6 months and 1 to 2 years, triglycerides at 6 months and 1 to 2 years, height‐for‐age z‐score at > 12 months, and height at 1 to 2 years.
GRADE Working Group grades of evidenceHigh quality: we are very confident that the true effect lies close to that of the estimate of the effect.
 Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
 Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
 Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.