I couldn't help noticing that Greuze seemed to be losing weight.
I wanted to point it out to Greuze but I figured it would be rude to tell him that I figured he was losing quite an unhealthy amount of weight for his age. 
mnli hypothesis: I wanted to point it out to Greuze but I figured it would be rude to tell him that I figured he was losing quite an unhealthy amount of weight for his age.  premise: I couldn't help noticing that Greuze seemed to be losing weight.