Pros and cons
Pros
- Recorded at point of consumption so there is no reliance on an individual’s memory
- Portion size often well described so estimates are usually good and this reduces error associated with quantification
- Detailed description of foods consumed are provided which enhances the accuracy of diet coding
- All eating occasions are recorded in real time
- Surrogates can be used for those not able to complete a written record, such as parents/carers for young children and carers/adult children for the elderly
- Meals can be photographed to aid interpretation of portion size and details of food items consumed
- Recordings can be made away from home relatively easily and the method is flexible and suits people with erratic lifestyle habits
- It is suitable for the assessment of foods eaten regularly
- Provides good estimates of energy and most nutrients, foods and food groups
Cons
- It is time consuming and costly to turn the diaries into nutrient data
- The individual must be literate and be motivated as the method imposes a large burden, although much less than the weighed method
- The individual may alter his/her diet to make it easier to record, or to cover up poor eating habits
- Subjects may forget to record food items or even meals consumed
- The portion sizes of some foods may be difficult to estimate if the description given by the individual is inadequate
- The assessment of foods eaten less than once or twice a week may not be accurate
- Several days of recording are necessary because of daily variations in what people eat (minimum 3 days); seven days are commonly recorded but recording can become less accurate towards the end of the period because of study fatigue.
- For children foods eaten when not in the charge of parents may be missed or less accurately recorded