The association between adiposity and milk and alternative (milk and alt.) intakes in prepubescent children is unclear. This study assessed the impact of a family‐based lifestyle intervention on adiposity in overweight (n= 14) and obese (n=64) children (age 7.5 ± 0.78 y). Children were randomized to control (CTRL) [no intervention], standard (SInt) [2 milk and alt./d] or intensive (IInt) [4 milk and alt./d] interventions focused on meeting the Canadian food and activity guides. Measurements were height (Ht; m) and weight (Wt; kg) to compute body mass index for‐age‐ z‐scores (BAZ) using WHOAntroPlus Software (WHO 2007), waist circumference (WC; cm) and percentage body fat (%BF) assessed using dual‐energy X‐ray absorptiometry. Using mixed model ANOVAs, no differences were seen at baseline among groups for BAZ or %BF. At 6‐months, Ht increased compared to baseline (p=0.898) and was not different among groups. Compared to baseline, %BF (‐2.4±0.92%; p=0.0015) and BAZ (‐0.5±0.08; p<0.001) was reduced only in IInt whereas WC increased only in CTRL (+2.5±1.61 cm; p=0.007). These preliminary results demonstrate the short‐term benefits of participating in a lifestyle intervention focused on increased milk and alt and activity guidelines in the context of the family environment. Study funded by the Dairy Farmers of Canada Research Cluster Initiative (Agriculture and Agri‐Food Canada, Dairy Farmers of Canada and the Canadian Dairy Commission).Grant Funding Source: Dairy Farmers of Canada Research Cluster Initiative