When you have a cold or something and you go to the doctor, why do they weigh you first?

The weigh you first to keep a record of your weight.Usually to see if you are gaining or losing weight. Every one has a different body frame, there is certain weight to be sustained according to your frame and if you are a man or woman.If you are morbidly obese than he will tell you what foods to eat or not.Also exercising or swimming is good. Weighing any one is normal procedure in a hospital or clinic.Regardless of the symptoms.