Am I concerned or just judgmental?

My best friend has become obese. She used to be tall, willowy and stunningly pretty. Since having her family, she prepares meals full of fat and eats as if there were no tomorrow. She has changed from the beautiful girl I went to college with into a dowdy, matronly fat lady. She knows she is too heavy, but she continues to brag about how much she and her family enjoy her homemade biscuits, desserts etc. I feel very concerned about her health, but I also feel irritated by her behavior. Is there anything a friend can or should do? I will continue to love her as my friend, either way. I simply wonder if I have a real prejudice against obesity or if health concerns are driving me. What do you think?