I'm with Deborah and Slaw. The 10-15% "rule" applies to hatchlings and juveniles up to ~500g. I feed anything over that weight a small or medium (less likely) rat, once a week. Since I feed F/T, I sometimes have uneaten prey in the first round and then a big female will get seconds. My girls regain their prelay weights with no issue and have had zero issues with laying healthy eggs, and my males go off feed during a small part of breeding season but don't lose any weight. As the OP stated, his opinion was stated, not scientific fact.