Historically, it has been thought that the patient with cystic fibrosis (CF) has a voracious appetite. It is now becoming apparent that many patients do not have caloric intakes which meet their full energy requirements. Our study of CF patient, utilizing, a five-day written record of food consumptions and direct observation, supports this finding and points out the need for further nutritional counseling in providing optimal care for these patients. The cause of increased nutrient requirements and considerations for individualization of counseling are briefly discussed.