Bone Health is Maintained, While Fat Mass is Reduced in Pre-pubertal Children with Obesity Participating in a 1-Year Family-Centered Lifestyle Intervention

Abstract

Diet and physical activity (PA) influence bone health in children. This study tested whether increasing milk and milk products and weight-bearing types of PA favorably changed bone outcomes assessed by dual-energy X-ray absorptiometry (DXA) and bone biomarkers in children with obesity participating in a 1-year family-centered lifestyle intervention. Children were randomized to one of three groups: Control (Ctrl; no intervention), Standard treatment (StnTx: two servings milk and milk products/day; meet PA guidelines plus weight-bearing PA three times/week), or Modified treatment (ModTx: four servings milk and milk products/day; meet PA guidelines plus daily weight-bearing PA). Baseline and 12-month measurements included DXA scans for whole body (WB), lumbar spine (LS), lumbar lateral spine (LLS), and ultra-distal (UD) ulna + radius for bone mineral content (BMC), areal bone mineral density (aBMD) and BMD z-scores. Fat mass index (FMI), fat-free mass index (FFMI), and biomarkers of bone metabolism were assessed. Seventy-eight children 6-8 years old were recruited (mean body mass index for-age z-score: 3.3 ± 1.2). Compared to baseline, all groups increased BMC of WB, LS, and LLS (p < 0.001), whereas only StnTx increased UD ulna + radius BMC at 12 months (p < 0.05). At 12 months, WB-BMD z-scores were significantly lower in Ctrl (p < 0.05), whereas WB and LLS aBMD increased in StnTx and ModTx (p < 0.001) but not in Ctrl. All groups increased FFMI (p < 0.001), while only Ctrl increased FMI (p < 0.001). Bone biomarkers did not change over time. Participating in a family-centered lifestyle intervention based on Canadian diet and PA guidelines maintained bone health in obese children.

The Effects of Dairy Product Supplementation on Bone Health Indices in Children Aged 3 to 18 Years: A Meta-Analysis of Randomized Controlled Trials

“…The full-text review excluded 17 publications for various reasons ( Supplemental Appendix ). Finally, 21 [ [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] ] publications were included in the present meta-analysis.…”

“…The characteristics of the included RCTs are reported in Supplemental Table 1 . BMC and aBMD were measured by Lunar [ 8 , 10 , 12 , 15 ], Hologic [ 9 , 14 , 23 , 25 ], or Norland [ 13 , 18 , 27 ] DXA. Nine [ [8] , [9] , [10] , 13 , 15 , 17 , 18 , 24 , 25 ] RCTs enrolled only girls, 1 [ 12 ] enrolled only boys, and 11 [ 7 , 11 , 14 , 16 , [19] , [20] , [21] , [22] , [23] , 26 , 27 ] enrolled boys and girls (but sex-specific analysis was not performed).…”

“…BMC and aBMD were measured by Lunar [ 8 , 10 , 12 , 15 ], Hologic [ 9 , 14 , 23 , 25 ], or Norland [ 13 , 18 , 27 ] DXA. Nine [ [8] , [9] , [10] , 13 , 15 , 17 , 18 , 24 , 25 ] RCTs enrolled only girls, 1 [ 12 ] enrolled only boys, and 11 [ 7 , 11 , 14 , 16 , [19] , [20] , [21] , [22] , [23] , 26 , 27 ] enrolled boys and girls (but sex-specific analysis was not performed). Only one trial enrolled children at preschool ages (3–5 y) [ 16 ], whereas the remaining enrolled children at elementary to high school ages (≥7–18 y) [ [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] ].…”

“…Over the past few decades, the effects of dairy supplementation on bone mass parameters (BMC and areal bone mineral density [aBMD]), bone turnover markers, hormones related to bone metabolism (PTH, 25(OH)D, and IGF-I), and longitudinal bone growth (height) in children and adolescents have been examined in multiple randomized controlled trials (RCTs) [ [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] ] with small sample sizes and inconsistent findings. Based on the understanding acquired from the available qualitative (systematic) and narrative reviews [ 6 , [28] , [29] , [30] , [31] , [32] , [33] , [34] ] appraising some of those RCTs, dairy products appear to have the potential to improve bone health, mainly by increasing BMC and aBMD.…”

Effects of Milk and Milk-Product Consumption on Growth among Children and Adolescents Aged 6–18 Years: A Meta-Analysis of Randomized Controlled Trials

“…Studies investigating the association between milk and milk-product consumption and body growth, such as height, weight, and body composition, during childhood and puberty have reported inconsistent results (7)(8)(9)(10)(11). Evidence from a 1-y family-centered lifestyle intervention study investigating the impact of milk and milk-product consumption on prepubertal children with obesity reported that fat mass percentage was significantly decreased among children who consumed 4 servings milk and milk products/d compared with a control group (10). However, a longitudinal cohort study in children from ages 10 to 13 y reported lessfavorable changes in body weight and body fat for normal or overweight children consuming flavored milk compared with nonconsumers over a 2-y period (11).…”