Hamster weight loss??

[Rqven]

I have noticed a significant decrease of weight in my hamster, Prim. She has been exercising on her wheel and seems to be eating normally. She's only 9 months old so I doubt she is starting to lose weight due to old age. She gained a few grams before but has been losing weight for the past few months, is this normal? I'm starting to get worried

148g 6/24/21
146g 6/28/21
138g 7/10/21
118g 7/25/21