I can’t eat…like I don’t get hungry

So I’m in my early 20s. I noticed I struggle with eating…like I can’t. Yesterday, I had ramen noodles and a milkshake, and felt sick. The other day, I had chicken nuggets for dinner. Some days, I don’t remember to eat until later in the day. In the mornings, I’m sick and physically can’t eat. I’ve had people tell me that I need to eat more, but I just physically can’t at times. I haven’t lost any weight or anything. I’m at a healthy weight. So I figure it’s fine. I always feel a little awkward when people lecture me about my eating habits. Does anyone else deal with this?