Expectations May be Too High for Changing Diets of Pregnant Teens

Expecting to change the diets of low income pregnant teenagers through less than nine months of nutrition education may be as unrealistic as it is desirable. Instead, we may need to look at other positive changes resulting from nutrition education and hope for dietary changes to follow in the future.

That dietary improvement is desirable for pregnant teens is well documented. Infants born to teenage mothers have a lower chance of survival than infants born to older women, probably due to the high incidence of low birthweight babies born to teens. Maternal weight gain necessary for optimal infant birth weight is greater for teens than for older women (Frisancho, Matos & Flegel, 1983). Yet teens are less likely to gain needed weight during pregnancy. Thus, helping a teen gain more weight may improve chances for infant survival by decreasing incidence of low birthweight infants (American Dietetic Association, 1989).

The University of Georgia Cooperative Extension Service has operated in selected counties a TeenAge Mothers (TAMS) project funded by the Expanded Food and Nutrition Education Program (EFNEP). The main objectives were to improve the chance of infant survival by:

1. increasing the mother's knowledge of nutrition,

2. leading to an improved maternal diet,

3. thereby increasing weight gain during pregnancy, and

4. decreasing the percentage of low birthweight babies born to teens.

Results from an evaluation of TAMS showed there was a significant increase in knowledge of nutrition. However, this did not lead to a measurable improvement in maternal diet. Should we have expected to see a change in diet or were our expectations for diet improvement too high for this population? Examining the TAMS evaluation provided insights into answering these two questions.

Methods and Results

EFNEP paraprofessionals were trained to recruit and teach groups of pregnant teens using a nine-month curriculum developed for this project. One hundred thirty-four pregnant teens were evaluated the first year (1991) and 304 pregnant teens were evaluated the second year (1992). More than 80% of the teens were African-American and the remaining were white. The median age was 16 years old, with a range from 9 to 21 years old.

A significant improvement was seen in knowledge of nutrition as evidenced by change in pre and post "knowledge" tests (p<.001 using a student's t-test for paired samples). Unfortunately, results from both pre- and post-24 hour diet recalls and pre- and post-food frequencies (used to show improvement in behavior) did not show significant improvements in diet. This indicates that knowledge did not transfer into improved diet behavior or that diet recalls and food frequencies did not capture the diet improvement that was made. Weight gain occurred in spite of the fact that diet recalls did not show improvement in diet, and we were able to verify the importance of weight gain during pregnancy. As expected, the total weight gain of the TAMS teens was positively correlated with birthweight (r = .3, p = .003 for the first year and r = .25, p = .001 for the second year).

Both years TAMS participants had fewer low birthweight babies than expected in all age categories except for the 18 to 19 and 20 to 24 year old categories the second year (see Table 1). The number in the 20 to 24 age category was too small to be representative.

It should not be surprising that increased knowledge of nutrition does not necessarily lead to improvement in diet. Even dietitians (who have studied nutrition more than most) do not always put their knowledge into practice (Vandergraff, Evers & Mayfield, 1992). On the other hand, EFNEP has been successful in improving diet of homemakers in general as evidenced by improved 24 hour diet recalls (Del Tredici, Joy, Omelich & Laughlin, 1988). What is different about pregnant teens? There may be several explanations.

One possibility is that nine months or less of TAMS classes has only accomplished the first step of many steps leading to diet change. Prochaska, Velicer, DiClemente, Guadagnoli, and Rossi (1990) proposed that behavior change progresses through four stages--precontemplation, contemplation, action, and maintenance. It may be that low-income pregnant teens take longer than nine months to move through these stages. As with other Extension programs for youth, the TAMS classes may need to last throughout the teen years to make a difference.

Another possibility is that teens may not have control over what they eat (Schneck, Sideras, Rox & Dupuis, 1990). Parents or other family members may make all the decisions concerning food for the family. Diet changes may not occur until the teen actually shops and prepares her own food.

In addition, diet changes may not occur because the teen does not feel in control, even if she buys and prepares the food. Focus groups with teens have indicated that teens have an external locus of control--they feel that other people are responsible for their eating behavior. Usually the mother or boyfriend plays the monitoring role. This could mean that significant others may need to be involved in a program to facilitate diet changes (Brown, Tharp, McKay, Richardson, Hall, Finnegan & Splett, 1992). To be successful, the TAMS classes may need to include significant others. In addition, the teens may need education in areas such as self-esteem, which may help them make decisions for themselves.

TAMS classes have been able to reach and keep teens as participants, indicating that the material is of interest to this population. As other research has indicated, the benefits of nutrition education might be seen in the long term rather than in an individual pregnancy (Brown, Tharp, McKay, Richardson, Hall, Finnegan & Splett, 1992). Perhaps with TAMS as a drawing card, these teens can continue to be involved in nutrition activities which will eventually lead to improved eating habits for them and their children.

American Dietetic Association. (1989). Nutrition management of adolescent pregnancy. Journal of the American Dietetic Association, 89, 104-109.

Brown, J. E., Tharp, T. M., McKay, C., Richardson, S. L., Hall, N. J., Finnegan, Jr., J. R., & Splett, S. L. (1992). Development of a prenatal weight gain intervention program using social marketing methods. Journal of Nutrition Education, 24, 21-28.

Del Tredici, A. M., Joy, A. B., Omelich, C. L., & Laughlin, S. G. (1988). Evaluation study of the California expanded food and nutrition education program: 24-hour food recall data. Journal of the American Dietetic Association, 88(2), 185-190.

Frisancho, A. R., Matos, J., & Flegel, P. (1983). Maternal nutrition status and adolescent pregnancy outcome. American Journal of Clinical Nutrition, 38, 739.

Health Assessment Services Unit. (1993). In-house planning data (1988-1992). Atlanta: Georgia Division of Public Health, Georgia Center for Health Statistics.

Prochaska, J. O., Velicer, W. F., DiClemente, C. C., Guadagnoli, E., & Rossi, J. S. (1990). Patterns of change: Dynamic typology applied to smoking cessation. Behavioral Research 26, 83-107.

Schneck, M. E., Sideras, K. S., Rox, R. A., & Dupuis, L. (1990). Low-income pregnant adolescents and their infants: Dietary findings and health outcomes. Journal of the American Dietetic Association, 90, 555-558.

Vandergraff, D. J., Evers, W. D., & Mayfield, B. J. (1992). Effect of a state dietetic association's weight management program on its members. Journal of the American Dietetic Association. 92(92), 865-866.