A technique is disclosed by which a weight scale, having electronic output, is couplable to a processing device such as a computer, and preferably, a hand-held computer, PDA, cell phone or the like. The processing device is configured to receive weight inputs from the weight scale and identification information of the food or food ingredients being weighed, and then convert the gram weight of the food into grams of carbohydrate and protein for that food. For diabetes applications, the process also converts the carbohydrate and protein information into rapid-acting insulin dosages which can then be used to determine manually the amount of insulin to be dosed to the person with diabetes. In a preferred embodiment, the calculated insulin dosages information is automatically provided to a insulin pump or other automatic means of dosing insulin to a patient to thereby automatically dose the patient properly.