In his statement, Prof. Dr. Birkenfeld emphasizes that a decrease in muscle mass in the context of successful weight loss is usually a physiological adaptation:
"Greater weight loss is usually accompanied by an adjustment in muscle mass [...]. Overall, the evidence – including evidence from imaging and animal studies - suggests that muscle changes under incretin RA therapy are primarily adaptive: the lower muscle volume is in line with expectations depending on age, disease burden, and extent of weight loss - and is comparable to the effects of diets or bariatric surgery."
At the same time, Prof. Dr. Birkenfeld emphasizes that sufficient protein intake and regular physical activity remain essential. Combination therapies with anabolic substances should be reserved for special situations and remain the exception.
You can read the full article from Deutsches Ärzteblatt here.