Aww sis, normal lang yan sa second pregnancy, maraming moms I know experienced the same thing, parang ang body mo na lang eh alam na what to expect kaya hindi na sya ganong eager to eat hehe. But honestly, it could also be hormones, stress, or even kung busy ka na with your first baby kaya you're forgetting to eat properly, I did that din, nakadiscover lang ako when I felt super lightheaded one afternoon! I'd suggest checking with your OB about it since you're pregnant, para ma-rule out any issues at ma-ensure baby's getting enough nutrition. In the meantime, try small frequent meals instead ng malalaking servings, and eat whatever you're craving (guilt-free!) to keep your strength up.