Resistance training as a key strategy for high-quality weight loss in men and women.

Total weight loss was similar across exercise groups in men despite differences in body composition outcomes.

• Men's total weight loss: NO: -8.5 kg ± 3.2 kg; AR: -9.0 kg ± 4.2 kg; RT: -7.7 kg ± 4.2 kg
• Study included 183 men and 121 women aged 20-74 years with BMI 18.5-45 kg/m²
• Mean follow-up was 5.1 months ± 0.42 months
• Diet was designed to provide an individualized energy deficit of approximately 500 kcal/day calculated relative to each participant's measured RMR and total estimated daily energy expenditure
• Body composition was assessed using dual-energy X-ray absorptiometry (DXA)

In men, resistance training produced the greatest fat mass reduction and was the only modality associated with an increase in fat-free mass.

• Fat mass reduction in men: RT: -8.9 kg ± 4.1 kg; AR: -7.8 kg ± 3.2 kg; NO: -5.8 kg ± 2.5 kg
• Fat-free mass change in men: RT: +0.8 kg ± 5.0 kg; AR: -1.1 kg ± 2.0 kg; NO: -2.8 kg ± 1.4 kg
• RT was the only modality associated with an increase in fat-free mass in men
• Both aerobic exercise and no exercise groups lost fat-free mass in men

In men, abdominal circumference declined in all groups but with larger reductions in resistance training and aerobic exercise compared to no exercise.

• ABC reductions in men: RT: -9.0 cm ± 3.7 cm; AR: -8.0 cm ± 3.2 cm; NO: -6.1 cm ± 2.4 cm
• All three groups showed significant reductions in abdominal circumference
• RT and AR both produced larger ABC reductions compared with NO

In women, resistance training produced the greatest fat mass reduction and was the only modality that increased fat-free mass.

• Total weight loss in women: NO: -7.13 kg ± 3.27 kg; AR: -6.43 kg ± 3.53 kg; RT: -5.42 kg ± 3.76 kg
• Fat mass reduction in women: RT: -6.36 kg ± 3.82 kg; NO: -5.47 kg ± 2.64 kg; AR: -4.10 kg ± 3.17 kg
• Fat-free mass change in women: RT: +0.90 kg ± 1.24 kg; NO: -2.94 kg ± 1.40 kg; AR: -0.37 kg ± 1.45 kg
• RT was the only modality that increased FFM in women; both NO and AR experienced FFM loss

The fat mass-to-weight loss ratio was highest in the resistance training group, indicating superior weight loss quality.

• FM-to-weight loss ratio: NO: 0.7 ± 0.2; AR: 0.86 ± 0.2; RT: 1.1 ± 0.7
• RT ratio was significantly higher than NO (p = 0.0002) and AR (p = 0.0051)
• A ratio exceeding 1.0 in the RT group indicates that fat mass loss exceeded total weight loss, consistent with simultaneous FFM gain
• This ratio was described as a measure of 'high-quality weight loss'

Abdominal circumference reduction correlated strongly with fat mass loss across participants.

• Pearson correlation between ABC reduction and FM loss: r = 0.84; p = 0.0001
• This correlation highlighted ABC's utility as a marker of high-quality weight loss
• ABC was measured as a marker of central obesity

The study design was a retrospective cohort in which participants self-selected their exercise modality.

• Total sample: 304 adults (183 men, 121 women)
• Participants self-selected RT, AR, or NO exercise while following a hypocaloric diet
• Age range: 20-74 years; BMI range: 18.5-45 kg/m²
• The retrospective and self-selected design is a methodological limitation noted in the study