Effects of BodyPump and resistance training with and without a personal trainer on muscle strength and body composition in overweight and obese wom... - PubMed - NCBIwww.ncbi.nlm.nih.gov
Twelve weeks of BodyPump did not improve muscle strength in overweight women, but a personal trainer amplified the effects of individual resistance training on maximal strength in squat. None of the intervention groups showed effect in body composition."
I would add that this is another proof that exercise alone hardly makes you lose fat. To lose fat, change your diet.