The two male athletes that had the best lift progression (Jason and Felix) gained about 7-8lbs in the process but both are very lean (Jay is a true 6% maybe even a tad less).
Both are 6'1" and started out at 205 and ended up at 212 and 214. One weird thing is that they actually gained more muscle at first but lost some in the last phase which is basically only doing the competitive lifts and squats. At one point both were 218.
Also note that Jay was doing Crossfit in the afternoon which obviously limited the size gains he made.
Strength wise Jay went from 235 in the snatch to 285 (actually even tried 300 at a crossit competition. held it overhead but lost it) and his clean & jerk went from 335 to 375 (he also cleaned 380). NOTE: his technique was REALLY hit or miss prior to this training cycle. He was very strong but his Olympic lifts didn't follow. So his improvement on the Olympic lifts are super impressive but are also due to a great technical improvement. His back squat went from 465 to 500 (the program doesn't have much back squat) and his front squat went from 385 to 425. He also deadlifted 600 at a crossfit competition even though we didn't train the powerlifting deadlift.
Felix went from a 235 snatch to 265, almost making 275 (had it overhead, failed to stabilize it). His clean improved from 315 to 345 but at the end of the cycle his jerk suffered a major technique breakdown that has been fixed now, but he is just starting lifting heavy again. Felix was a much better technician at the beginning, explaining why the improvements are not as steep. His front squat went from 335 to 375 and we didn't test the back squat because of a slight knee issue.