What Causes Nausea And Sweating After Eating?

I have a 20 year old daughter, who over the last week or so, right after she eats she has nausea, and breaks out in a sweat, she does not throw up a lot just a little. She is a college athlete, she has 2-3 work outs a day. She has lost 15lbs in last 3 months (she was trying to and with all the work outs it comes off easy). She is not pregnant any other suggestions?