Unfortunately, many senior foods are formulated with lower protein levels and may contribute to loss of lean body mass in older pets. (1800petmeds.com)
You can push it faster, but it will come with a greater loss of lean body mass...» (completehumanperformance.com)
Despite this level of protein intake, lean tissue losses occurred promptly and persisted for 2 weeks, after which «nitrogen balance» (ie, no further loss of lean body mass) was re-established. (blog.virtahealth.com)