Changes in visceral adiposity, body composition, and cardiometabolic profiles following a supervised mixed exercise program in women with normal-weight obesity and obesity

Objective Normal-weight obesity (NWO) describes individuals with a normal body mass index (BMI) but elevated adiposity, potentially underestimating cardiometabolic risk. Mixed exercise may be particularly relevant for NWO, as it targets body composition, visceral adiposity, and cardiorespiratory fitness rather than weight loss alone. This study examined 12-week changes in DXA-derived body composition, regional adiposity, cardiorespiratory fitness, and cardiometabolic biomarkers in women with NWO and obesity (OB). Methods Sixty-seven women aged 22–45 years who completed baseline and post-intervention assessments were included in the per-protocol analysis (NWO n = 32; OB n = 35). Participants were classified using predefined BMI and DXA-derived body fat criteria. Changes in outcomes were evaluated using 2 × 2 mixed-model repeated-measures ANOVA, with false discovery rate correction applied to within-group contrasts. Results After 12 weeks, body weight and BMI decreased in the OB group but remained unchanged in the NWO group. Both groups demonstrated favorable changes in body composition. Total fat mass decreased from 24.68 ± 4.76 to 22.75 ± 3.84 kg in NWO and from 31.31 ± 3.91 to 29.46 ± 4.29 kg in OB, while total lean mass increased from 33.38 ± 4.00 to 34.70 ± 4.97 kg in NWO and from 39.04 ± 5.87 to 39.53 ± 5.90 kg in OB. Reductions were also observed across regional fat depots, including visceral adipose tissue (VAT), android fat, and gynoid fat. VAT decreased by − 58.2 g (95% CI, − 95.3 to − 21.1) in NWO and − 77.1 g (95% CI, − 109.4 to − 44.8) in OB, with parallel reductions in android and gynoid fat mass. The android-to-gynoid ratio showed minimal change. Cardiorespiratory fitness improved in both groups, with VO₂max increasing by 3.73 mL·kg − 1 ·min − 1 (95% CI, 0.75 to 6.72) in NWO and 3.03 mL·kg − 1 ·min − 1 (95% CI, 1.45 to 4.61) in OB. No significant group×time interactions were observed. Routine fasting cardiometabolic biomarkers showed limited or inconsistent changes after correction. Conclusions A 12-week supervised mixed-exercise program improved adiposity and cardiorespiratory fitness in women with NWO and OB, independent of weight loss in NWO. No phenotype-specific differences were detected. These findings highlight the importance of assessing body composition beyond BMI, although causal inference is limited by the single-arm design. Trial registration ChiCTR2100047173, registered on 9 June 2021, retrospectively registered.