"Dietary methods of assessment include looking at past or current intakes of nutrients from food by individuals or a group to determine their nutritional status. There are several methods used to do this.\n\nFor a 24 hour recall, a trained professional asks the subject to recall all food and drink consumed in the previous 24 hours. This is a quick and easy method. However, it is dependent upon the subject’s short-term memory and may not be very accurate.\n\nWith a food frequency questionnaire, the subject is given a list of foods and asked to indicate intake per day, per week, and per month. This method is inexpensive and easy to administer. It is more accurate than the 24 hour recall.\n\nFood intake is recorded by the subject at the time of eating in a food diary. This method is reliable but difficult to maintain. It is also known as a food journal or food record.\n\nObserved food consumption requires food to be weighed and exactly calculated. It is very accurate but rarely used because it is time-consuming and expensive."