Dietary assessment

Definition

During a dietary assessment an individual's food intake is recorded and analyzed.

Purpose

A dietary assessment is done to help provide insight into the possible cause of symptoms, or to provide recommendations for better eating to improve health. Many disease and conditions have a dietary component. A dietary assessment can help the doctor diagnose or rule out the causes of certain problems. In some cases a dietary assessment is done to determine the general eating habits of an individual so that a nutrition professional can make recommendations for improved heath. A good diet is an integral part of the treatment plan of many diseases and conditions.

Precautions

A dietary assessment can be an extremely valuable tool for helping individuals improve health, and for diagnosing a variety of diseases and conditions. However, getting an accurate accounting of an individual 's food and beverage intake can be very difficult. Even when the intention to be completely honest exists, individuals who eat very little tend to over report their intake, while individuals who eat larger than average amounts tend to underreport their intake. For this reason dietary assessment tools that use objective measures, rather than relying on selfreporting, may be more accurate.

Dietary assessment can also be very challenging for special populations. Individuals who have Alzheimer 's, dementia, or other diseases and conditions that affect memory are difficult to perform an accurate dietary assessment for. However, these individuals are often in the greatest need of a complete assessment, as memory problems can cause problems with skipping meals or eating too frequently. This can lead to a variety of health and other problems which may be manageable with dietary intervention. The involvement of caregivers in the dietary assessment process can help improve the accuracy of the assessment, which in turn can lead to improved health outcomes.

Description

The goal of the dietary assessment is to determine the general eating habits of the individual. This can be done in a number of ways. A nutrition professional often must make tradeoffs between accuracy and time efficiency when performing a dietary assessment.

The most basic form of dietary assessment is a 24 hour food questionnaire or interview, during which the individual self-reports the food consumed in the previous 24 hours. One positive aspect of this type of dietary assessment is that it is usually very short, and can be completed in one appointment. A negative aspect of this type of assessment is that it tends not to be very accurate. What an individual ate in the previous 24 hours is not necessarily representative of the food eaten during an average 24 hour period. It also relies on self-reporting, with the individual having to guess the portion sizes consumed. Because reporting portion sizes larger or smaller than those actually consumed can have a drastic impact of the assessment, this can provide a fairly inaccurate result in some cases. This type of assessment can, however, provide basic insight into dietary habits overall.

In some cases a food frequency questionnaire is used instead of a 24 hour food questionnaire. A food frequency questionnaire asks the individual how many times in a certain time period he or she usually eats a certain food or class of foods. For example, the questionnaire might ask whether the individual usually eats eggs daily, two to four times a week, five to seven times a week, or less than once a week. This type of questionnaire can help the nutrition professional understand an individual's eating habits outside the context of a specific day. This type of questionnaire is often helpful at suggesting broad dietary changes that may be helpful, such as trying to cut back slightly on red meat, or eating more vegetables.

A more in-depth type of dietary assessment is the food record. During a specific assessment time period, such as a day or a week, the individual keeps a journal in which he or she writes down each item consumed, the time and place it was consumed, the quantity of food, how it was prepared, and any other information indicated by the nutrition professional. In some cases the individual is instructed to weigh all food, keeping a weighed food recorded. Food records help the nutrition professional get a more accurate picture of the individual's dietary habits. The record tends to be more accurate, as each food is written down before it is eaten, and the assessment does not rely on later recall. Weighed food records can be even more accurate because they do not rely on self-reporting of portion sizes.

Some nutrition professionals have begun to use photographic and video technologies to do dietary assessments. In these cases, the individual is instructed to take a photo of each food before it is consumed, and may be instructed to photograph the preparation of the food, and the setting in which it was eaten (for example, at a party, at the dinner table, in front of the television). When a video camera is used the individual might be instructed to videotape each food, or the camera may be set up in the kitchen or another location where the individual usually eats.

Preparation

No special preparation is required for a dietary assessment.

Aftercare

No aftercare is required after a dietary assessment.

Complications

No complications are expected from a dietary assessment.

QUESTIONS TO ASK YOUR DOCTOR

• What types of foods am I getting too much of?
• What types of foods am I getting too little of?
• Can you recommend a nutrition professional who can help me improve my dietary habits?

Results

Adietary assessment does not usually yield specific results. Instead, it gives the doctor or nutrition professional a general picture of the individual's dietary habits. In some cases, this can be used to help diagnose or rule out diseases. For example, a diet found to be extremely low in iron could be the cause of the most common type of anemia , iron deficiency anemia . If the individual had visited the doctor with symptoms such as fatigue, dizziness , weakness, and pale skin, all symptoms of anemia, increasing the amount of iron in the diet may relieve these symptoms.

The results of a dietary assessment can also help the doctor or nutrition professional make recommendations about dietary changes that can improve health. The suggestions may be intended to help promote weight loss or weight gain, improve general health, or be designed to help improve a specific disease or condition. There are many different diseases and conditions that dietary changes can help improve. For example, eating a diet that is low in salt can help improve high blood pressure .

Caregiver concerns

A dietary assessment can be done for many different reasons. If a doctor believes that there may be a dietary component to a problem, or if he or she believes dietary intake information will help in making a diagnosis, a doctor may order a dietary assessment. Although a doctor may do a basic dietary assessment, in most cases the individual is referred to a nutritionist , a registered dietician , or certified dietetic technician. The results of the assessment are then reported to the physician. The nutritionist, registered dietician, or certified dietetic technician works closely with the individual and the physician. He or she can also work closely with social workers, hospital or clinic staff, family members, and any other members of the individual's health care team. In this way the individual can have regular dietary assessments to chart progress, and he or she can receive the best nutrition possible for his or her health goals.

Resources

books

Bender, David A. Introduction to Nutrition and Metabolism, 4th ed. Boca Raton, FL: CRC Press, 2008.

Escott-Stump, Sylva. Nutrition and Diagnosis-Related Care, 6th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2008.

Moore, Mary Courtney. Pocket Guide to Nutritional Assessment and Care, 6th ed. St. Louis, MO: Mosby, 2009.

periodicals

Keller, Colleen, Julie Fleury, and Andriana Rivera. “Visual Methods in the Assessment of Diet Intake in Mexican American Women.” Western Journal of Nursing Research 29.6 (October 2007): 758-774.

Pennington, Jean A.T., et al. “Food Composition Data: The Foundation of Dietetic Practice and Research.” Journal of the American Dietetic Association 107.12(December 2007): 2105–2114.

Stumbo, Phyllis J. “Considerations for Selecting a Dietary Assessment System.” Journal of Food Composition and Analysis 21.1 (February 2008): S13–S19.

organizations

American Dietetic Association, 120 South Riverside Plaza, Suite 2000, Chicago, IL, 60606-6995, (800) 877-1600, www.eatright.org.

USDA Center for Nutrition Policy and Promotion, 3101 Park Center Drive, Room 1034, Alexandria, VA, 22302-1594, (888) 7-PYRAMID, www.mypyramid.gov.

Helen Davidson