From my understanding, only the ArA supplementing group had the hypercaloric diet. Both groups seemed to gain around 1 kg (2.2 lbs I think that is?) at the end of the 50 days. So lean body mass gains wasn't different but what's interesting is the fat gain. 50 days on that hypercaloric diet for the ArA group and with only .5 kg (roughly 1 lbs) of fat gain, that's pretty good IMO. If anything, the study may have short changed the body compositional effects of ArA supplementation by not giving the placebo group a hypercaloric diet as well.
Let's just say this, the ArA group had a diet which was around 550 calories more per day than the placebo group. That should net you a weight gain of 1 lbs per week with obviously a good amount of fat gain per lbs. The fact that after 50 days, the ArA group only gained around 1 lbs of fat mass, that's pretty good. If anything, it would appear that the ArA supplementation kept the fat mass gain at bay which one could look at as a positive factor towards body composition changes.