Using encoding and retrieval strategies to improve 24-hour dietary recalls among older adults

Objective To examine whether using an encoding strategy and/or providing more support at the time of retrieval improves the accuracy of 24-hour dietary recalls among the elderly. Design Posttest-only control group design. Setting The sample was recruited through advertisements and at senior centers and a low-income apartment building in rural central Pennsylvania. Subjects Study participants were 21 men and 73 women aged 58 years old and older. Everyone completed the study. Intervention The treatment group was unobtrusively guided in use of an encoding strategy before consuming the prepared meal. Main outcome measures A 24-hour dietary recall and recognition tests were administered the next day for the foods consumed at the meal and for serving sizes of 5 of the foods. Memory tests were also administered. Statistical analyses performed Linear regression was used to examine differences between the treatment and control groups and to identify variables that explained variation in the number of foods correctly recalled or recognized. The chi(2) test was used to examine correct vs incorrect recall or recognition of the serving sizes of the 5 foods between the groups and to identify explanatory variables for this task. Results Subjects remembered more foods when they used an encoding strategy and when recognition replaced free recall; they performed best when both strategies were used. Use of this encoding strategy did not improve accurate recall or recognition of serving sizes of 5 foods; however, performances did improve when recognition replaced free recall. Conclusions Among older adults, use of an encoding strategy and provision of support at the time of retrieval enhances memory of foods consumed but not of amounts consumed. To strengthen memory of foods consumed, older adults need to perform effortful memory tasks when they are eating.