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Table 5 BMI, BMI standard deviation score (SDS)a and changes during childhood/adolescence according to weight classb

From: Tracking of overweight and obesity from early childhood to adolescence in a population-based cohort – the Tromsø Study, Fit Futures

Age/ age interval

Thin/normal weight at 2–4 years of age  (n = 471)

Overweight/obese at 2–4 years of age  (n = 61)

 

Thin/normal weight at 5–7 years of age  (n = 459)

Overweight/obese at 5–7 years of age  (n = 73)

 

Mean

(SD)

Mean

(SD)

p-value

Mean

(SD)

Mean

(SD)

p-value

BMI kg/m2

2–4 years

15.94

(1.06)

18.71

(0.89)

<0.001

 

5–7 years

15.54

(1.50)

18.32

(2.92)

<0.001

15.27

(1.01)

19.53

(2.29)

<0.001

15–17 years

21.80

(3.82)

25.09

(5.74)

<0.001

21.31

(3.08)

27.63

(5.95)

<0.001

Change in BMI kg/m2

to 5–7 years

−0.40

(1.29)

−0.39

(2.74)

0.051

 

to 15–17 years

5.85

(3.66)

6.38

(5.73)

0.66

6.03

(2.76)

8.10

(4.84)

0.001

BMI SDS

2–4 years

−0.17

(0.84)

1.73

(0.47)

<0.001

 

5–7 years

0.07

(0.88)

1.45

(1.10)

<0.001

−0.06

(0.70)

2.03

(0.72)

<0.001

15–17 years

0.35

(1.04)

1.13

(1.12)

<0.001

0.25

(0.95)

1.69

(1.01)

<0.001

Change in BMI SDS

to 5–7 years

0.24

(0.78)

−0.29

(1.02)

<0.001

 

to 15–17 years

0.53

(1.11)

−0.60

(1.14)

<0.001

0.30

(0.85)

−0.34

(0.84)

<0.001

  1. A sub study of The Tromsø Study: Fit Futures N = 532: 279 boys, 253 girls
  2. aBMI SDS is calculated using LMS values based on an international reference population of children [28]
  3. bWeight classes are based on BMI according to the International Obesity Taskforce’s age- and sex-specific cut-off values in children 2–18 years: thinness: adult BMI <18.5 kg/m2, normal weight: adult BMI ≥18.5- < 25 kg/m2, overweight: adult BMI ≥25- < 30 kg/m2, obesity: adult BMI ≥30 kg/m2 [28]
  4. Mann–Whitney U test for comparing groups. Monte Carlo sig. (2.tailed) confidence level 99 %
  5. CI for mean change in the two groups: −0.40 (CI: −0.58 - -0.23) -0.39 (CI: −1.46 - 0.68)
  6. BMI body mass index, LMS LMS curves/ LMS method: median (M), coefficient of variation (S) and skewness (L), SD standard deviation, SDS standard deviation score