TABLE 1

Trends in the Means of WC and WHtR Among US Youth Aged 2 to 19 Years: NHANES III (1988–1994) to NHANES 1999–2004

Age, yNHANES III (1988–1994)NHANES 1999–2000NHANES 2001–2002NHANES 2003–2004NHANES 1999–2004Relative Change, %aChange, PbTrends, Pc
NMeanSENMeanSENMeanSENMeanSENMeanSE
WC, cm
    Boys
        2–19516866.10.3204568.30.7214670.00.4195970.50.7615069.70.45.5<.0001<.0001
        2–5208450.70.135851.30.439651.80.438752.60.5114151.90.32.4<.0001.0006
        6–11162861.90.553962.90.858165.30.745364.80.7157364.50.54.1.0001.0002
        12–17113176.80.689178.70.787879.80.586180.60.6263079.80.44.0.0001<.0001
        18–1932581.31.225786.01.229185.21.025888.71.680686.60.86.6.0002.0007
    Girls
        2–19534265.10.4191067.80.5213268.60.7191669.70.6595868.80.45.7<.0001<.0001
        2–5217451.00.233751.60.540851.80.440852.00.3115351.80.21.6.0130.0153
        6–11158161.70.549863.10.558564.30.950866.60.6159164.70.55.0<.0001<.0001
        12–17125275.00.683378.40.891678.70.875679.31.1250578.90.55.2<.0001.001
        18–1933577.70.924283.41.122383.81.224484.31.470983.90.78.0<.0001.0002
WHtR
    Boys
        6–1930830.460.00216870.470.00417490.480.00215720.480.00450080.480.0024.3<.0001<.0001
        2–520810.500.0023550.500.0043920.500.0043810.510.00311280.500.0021.7.0028.0276
        6–1116270.460.0025390.470.0055810.480.0044530.480.00415730.480.0033.7<.0001.0001
        12–1711310.460.0048910.470.0048770.470.0038610.480.00426290.470.0024.1<.0001.0001
        18–193250.460.0062570.490.0082910.480.0062580.500.0098060.490.0056.4.0002.0012
    Girls
        6–1931680.460.00215720.480.00317230.490.00415080.490.00448030.490.0025.6<.0001<.0001
        2–521710.500.0023330.500.0034020.510.0033990.510.00311340.510.0020.9.0751.0777
        6–1115810.460.0034980.470.0055850.480.0045080.490.00415910.480.0024.7<.0001<.0001
        12–1712520.470.0038320.490.0059150.490.0047560.490.00725030.490.0035.6<.0001.0004
    3350.480.0062420.510.0062230.510.0082440.520.0097090.510.0048.1<.0001.0002
  • a Relative change between NHANES III (1988–1994) and NHANES 1999–2004.

  • b Pooled t test for H0: population differences in mean WC or WHtR between NHANES III and NHANES 1999–2004 = 0; degree of freedom = 93 (49 for NHANES III + 44 for NHANES 1999–2004).

  • c Tests for linear trends in the mean WC and WHtR were conducted in linear regression models for concatenated data of the 4 surveys (ie, NHANES III, NHANES 1999–2000, NHANES 2001–2002, and NHANES 2003–2004).