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Long-term behavioral effects of parent involvement in nutrition education
Long-Term Behavioral Effects of Parent Involvement in Nutrition Education BARBARA A. KIRKS AND CHRISTINE HUGHES Department of Horne Economics, California State University, Chico, Chico, California 95929-0002 Consumption of nutritious foods is a well-founded objective of nutrition education programs (1). Since the passage of P.L. 95-66, millions of dollars have been spent informing elementary school children about the importance of nutrition in their lives. Many of the nutrition education programs have urged a parent education component (2-4), but parent education is rarely mandated and seldom included. In an earlier study (5) we showed that primary-grade children (ages 5-9 years old) whose parents concomitantly received nutrition education were consuming a better diet than those whose parents were not directly involved. The present study was done to determine whether these effects were long-lasting. The current ages (10-14 years old) ofthe original participants contributed some further questions in regard to eating behavior because compared to the food habits of younger children (6) teen and preteen food habits are subject to many other influences. BACKGROUND In 1979. three schools were matched and randomly assigned to one of three groups: one in which both students and parents received regular nutrition education (SPI), one in which only the students received nutrition education (SI). and one control school. In addition to classroom nutrition education for their children, parents of the children in the SPI group received biweekly newsletters with nutrition information, had family menus analyzed for nutrient content, and had access to a dietitian five days a week to answer questions regarding food, nutrition, and health. At the end of the instructional period, we contacted the parents of the children in all of the groups and requested that they submit food records for their children for a 24-hour period. To avoid a pretest effect, this measurement was not made prior to instruction. The data collection instrument for the home foodchoice behavior consisted of a single-page questionnaire sent to the home by mail (Note 1). The questionnaire instructed the parent to indicate the number of servings of each of several listed food categories and to specify any "other foods" that the child had conVOLUME 18
NUMBER 5
1986
a
sumed during 24-hour period. From these data, we calculated dietary diversity and dietary quality scores by methods devised by Caliendo and Sanjur (7). Our dietary diversity score equaled the number of food categories mentioned (excluding certain calorically dense categories such as rich desserts, salty snacks, soft drinks, concentrated sweets, and fats) plus the number of "other foods" (up to 5). The maximum diversity score was 20-15 specified food cate.gories plus 5 other foods. The dietary diversity score does not directly assess the nutritional value of a diet. However, we consider high scores to be associated indirectly with nutritious diets because high scores indicate that the child consumed a wide variety of foods. Our dietary quality scoring system awarded 1 point for each of the Four Food Groups for which the ques-tionnaire data indicated that the recommended number of servings had been consumed, plus 1 point each for consumption of good sources of vitamin C, and vitamin A/folic acid. We pilottested the instrument, and validity and reliability were confirmed as reported earlier (5). We telephoned 10% of nonrespondents in all groups to obtain their food records and found no differences in any groups between respondents and nonrespondents. To validate our findings we solicited a second day's intake from a random group of respondents; again, we found no differences. Results of the original analyses of the returned food records showed that the children in the SPI group had both higher dietary diversity and dietary quality scores than did students in the SI group. And the scores for this latter group were higher in both categories than the scores of the control group students (Table 1). Vegetables were the only individual food group to show a significant difference between the subject groups. We concluded that the parents of the SPI children were providing a wider selection of foods in the home, and this behavior could probably be attributed to the parent education variable. PROCEDURE AND FINDINGS For this study, we used the original class lists and contacted the school district office to locate the students JOURNAL OF NUTRITION EDUCATION
203
Table 1. Mean scores for reported food consumption scores at the conclusion of the nutrition education program (Study I)
Mean Scores 1
Category
Maximum Score
Dietary quality Dietary diversity Meats/poultrylfish Fruits Juices Vegetables Milk/milk products Cereals
6 20 6 7 5 7 5 5
Student and Parent Instruction (n
=
Student Instruction
51)
(n - 50)
5.35" 12 .29" 3.14 3.02 2.02 3.57" 2.55 2.26
4.71b 11 .08 b 2.47 2.89 1.76 3.08" 2.31 2.36
Control (n
=
50)
4.24c 1O.18c 2.58 2.66 1.62 2.46 b 2.24 2.22
lWithin each horizontal row, means bearing different superscript letters are significantly different (p :5 .05).
who still resided in the area. We mailed the same food questionnaire used in the first study, along with a letter of explanation, to the parents of 275 (78%) of the original sample of 352 students. The form was completed by the parent in consultation with the student (Note 2). In 1980 the response rate was 151 (43%); our response rate this time was 111 (41 %). We scored the returned food records for dietary diversity and dietary quality, and for total foods within six groups: meat, poultry, and fish; milk products; vegetables; fruits; juices; cereals. We used analysis of variance to identify differences between groups, and when differences occurred we used a Duncan multiple-range test to identify the locus of difference (8) . The analyses showed that after five years, in general, the participants in the SPI group were eating a higher quality diet than the participants in either of the other groups (see Table 2). The dietary diversity
score, which had shown a significant difference in the earlier study, did not prove to be significantly different among the three groups. The diversity mean scores did, however, tend to show a difference between groups when parent nutrition education had been conducted, and this tendency reached levels of significance when the number of foods within individual food groups was examined. In looking at the number of vegetables, milk, and milk products that each group was consuming, we found that compared to the other groups the SPI participants were consuming significantly (p :5 . . 01) greater quantities of these foods. Cereals were also reported to be consumed in greater variety by this group (p :5 .05). It is interesting to note that the values for meat/poultry/fish as well as juices approach significance similar to the aforementioned two groups. Because caloric requirements change during adolescence, we also analyzed the data for differences be-
Table 2. Mean scores for reported food consumption (Study II)
Mean Scores 1
Category
Maximum Score
Dietary quality· Dietary diversity Meats/poultry/fish Fruits Juices Vegetables· • Milk/milk products·· Cereals·
6 20 6 7 5 7 5 5
Student and Parent Instruction (n = 48)
4.54" 9.50 2.88 2.38 1.92 3.50" 2.77a 2.50"
Student Instruction (n = 30)
3.47 b 10.77 2.23 2.20 1.47 2.27b 1.93 b 1.70b
Control
F
(n = 33)
Probability
3.94 8.76 2. 33 2.09 1.45 2.24b 2.03 b 1.90b
.0034 .3200 .0657 .5630 .0618 .0005 .0009 .0196
lWithin each horizontal row, means bearing different superscript letters are significantly different . An "*,, indicates significant differences between groups at the .05 level, and ,, * *" indicates significant differences between groups at the .01 level.
204
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1986
tween ages and sex, but we found no significant differences. We found that in almost every case, for all groups, the mean number of foods within individual groups was higher than it was five years ago. This undoubtedly was a result of the total increase in calories being consumed as the children grew older, as well as the fact that the children were eating a greater number of foods. We made the general assumption that the serving sizes increased somewhat for all foods in all groups and thus did not affect the findings.
DISCUSSION AND IMPLICATIONS Inclusion of the parent nutrition education component was time consuming and required additional effort and money. But the effects have shown that this aspect was most valuable and worthwhile. Over the intervening years we have received numerous comments and compliments from parents who were part of the program, and we strongly believe parent education can be the most important contribution of a school nutrition program. Limitations. One of the most interesting and certainly most uncontrollable aspects of the present study is the ages of the participants. Although family control of available food is almost total in early school years, we know it diminishes as adolescence approaches and that as children grow older they consume more foods away from home (9-12). Still, we hope that the effects of early nutrition education in terms of selecting nutritious food will be sustained throughout the age of psychological separation from parents, and that peer pressure will develop in favor of nutrient-dense foods. The overall dietary diversity score for the 24-hour recall period was not significantly different among the three groups, but the food-group analyses showed that a wider variety of foods was probably available in the homes in which parents as well as children had received nutrition education. In this study, participants' reported food choices appear to reflect the effects of the early nutrition education only when the parents concomitantly received nutrition education. While the records received from the home represented only a one-day intake, the validity of one-day recalls has been documented (10); and Young (11) has reported on the acceptability of groups means. Still, we cannot deny that access to foods outside the home occurs frequently, and that good nutrition is not highly valued among this age group. As one mother rather succinctly noted on her questionnaire: "Her diet would be better if only she weren't 13."
VOLUME 18 NUMBER 5
1986
Nutrition knowledge. Many studies in nutrition education have shown that cognitive scores almost always increase as a result of nutrition education programs (3,13). However, until recently, there has been little or no evidence of a relationship between nutrition knowledge and food behavior; the evidence of such a relationship has been particularly lacking in the results of studies of older children (13, 14). However, since recent meta-analysis of nutrition education programs has shown positive relationships between knowledge and food intake (15), such an analysis would have been an interesting addition to this study. Unfortunately, we were unable to test the students because they had been dispersed into a multitude of other classrooms, including a rotating junior high school classroom. On the other hand, we are certain that after the termination of the initial study there was no further parent nutrition education of these groups. Since the first author has been the ongoing nutrition consultant for the school district in which our study was done, we are aware of the nutrition education activities within the district. And after the termination of the initial study, nutrition education efforts were directed toward an entirely different segment of the accessible population.
Conclusion. When the parents were involved in the nutrition education program, a number of things happened. Within these families, there was learning early in life as well as an increase in knowledge and development of positive attitudes toward nutrition. Evidently the parents integrated the nutrition information they received into family food purchasing and meal preparation practices. Not only were nutritious foods available, but proper preparation as well as parent modeling of consumption of nutritious foods were also demonstrated. Thus, good nutrition is probably valued more highly now by both these children and their families. On the other hand, when the parents were not involved in the nutrition education program, we could not discriminate between the food behavior of the students who had nutrition education and those who did not. Although our sample was small, the initial population sample after a five-year delay provided evidence that by itself early nutrition education in school will not provide enough motivation to dictate behavior that will result in a better quality diet in pre- and early adolescence. It appears that the effects of early nutrition education in terms of food behavior are better when parents also receive nutrition information, and that the effects will probably not be sustained unless this factor is included.
JOURNAL OF NUTRITION EDUCATION
205
Finally, we recommend more research in this area. Longer studies that include several strategies and correlate behavior with changes in knowledge and attitudes are necessary. 0 NOTES 1 The first author developed the food-frequency recall, which is available upon request. 2 The Human Subjects for Research Committee at California State University, Chico, approved this study.
UTERATURE CITED 1 Ullrich, H. Towards a national nutrition education policy. Journal of Nutrition Education 1:8-10, 1969. 2 American Dietetic Association. Position paper on child nutrition programs. Journal of the American Dietetic Association 64:520-21, 1974. 3 Smith, H. M., and C. L. Justice. Effects of nutrition programs on third grade students. Journal of Nutrition Education 11:92-95, 1979. 4 Yperman, A. M., and J. Vermeersch. Factors associated with children's food habits. Journal of Nutrition Education 11:72-76, 1979. 5 Kirks, B. A., D. H. Hendricks, and B. W. Wyse. Parent involvement in a nutrition education program for primary grade students. Journal of Nutrition Education 14:137-40, 1982.
6 Mahan, L. K., and J. M. Rees. Nutrition in adolescence, St. Louis: C. V. Mosby Co., 1984, pp. 24-33. 7 Caliendo, M. A., and D. Sanjur. The dietary status of preschool children: An ecological approach. Journal of Nutrition Education 10:69-72, 1978. 8 Nie, N. H., C. H. Hull, J. G. Jenkens, K. Steinbrenner, and D. H. Bent. Statistical packages for the social sciences, 2d ed. New York: McGraw-Hill Book Co., 1975, pp.409-24. 9 Schorr, B. C., D. Sanjur, and E. C. Erickson. Teenage food habits. Journal of the American Dietetic Association 61:415-20, 1972. 10 Gersovitz, M. J., P. Madden, and H. Smiciklas-Wright. Validity of the 24-hour recall and seven-day record for group comparison. Journal of the American Dietetic Association 73:48-55, 1978. 11 Young, C. M. et al. A comparison of dietary study methods. I. Dietary history vs. 24-hour recall. Journal of the American Dietetic Association 28:218-21, 1952. 12 Bass, M. A., L. Wakefield, and K. Kolasa. Community nutrition and individual food behavior. Minneapolis: Burgess Publishing Co., 1979, pp. 82-85. 13 Lindholm, V. W., J. Touliatos, and M. F. Wenberg. Predicting changes in nutrition knowledge and dietary quality in ten- to thirteen-year-olds following a nutrition education program. Adolescence 19:367-75, 1984. 14 Byrd-Bredbenner, C. et al. Junior high home economics curriculum: Its effect on students' knowledge, attitude, and behavior. Home Economics Research Journal 11:123-33, 1982. 15 Axelson, M. L., T. L. Federline, and D. Brinberg. A meta-analysis of food and nutrition-related research. Journal of Nutrition Education 17:51-54, 1985.
DAIRY PRODUcrS AND PLASMA UPOPROTEIN LEVELS IN VEGETARIANS Vegetarians who habitually consume a diet that is low in fat and high in carbohydrate exhibit lower low-density lipoprotein (LDL) levels than nonvegetarians. Sacks and his colleagues (Journal of the American Medical Association 254:1337-41,1985) set out to determine the influence of fat ingestion from dairy products on the lipoprotein levels of lactovegetarians. To do this, researchers compared the lipoprotein levels of lactovegetarians with lipoprotein levels of vegetarians who consume no animal products. Dairy products were the major sources of saturated fat and cholesterol in the diets of 75 adult lactovegetarians studied. Twenty-eight percent of their calories were derived from fat, with a polyunsaturated-to-saturated ratio (PIS) of 1.0. In spite of the fact that they attempted to abstain from consuming all types of animal products, the strict vegetarians consumed dairy products on an average of three times a month. Their diets averaged 15% of calories as total fat, with a PIS ratio of 2.5. Mean total cholesterol, LDL, and high-density lipoprotein (HDL) levels of the lactovegetarians were 21 %, 24%, and 7% higher, respectively, than those of the strict vegetarians. The LDLlHDL ratio was 18% higher in lactovegetarians than in strict vegetarians, reflecting perhaps a greater sensitivity of LDL levels than HDL levels to the ingestion of fat from dairy sources. Considering available data both from epidemiological studies and from clinical trials, the investigators conclude that current recommendations to lower saturated fat and cholesterol intake, while increasing consumption of carbohydrate, will produce a relatively selective lowering of the LDL level while producing little, if any, decrease of the HDL level. 206
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NUMBER 5
1986
NUMBER 5
1986
a
sumed during 24-hour period. From these data, we calculated dietary diversity and dietary quality scores by methods devised by Caliendo and Sanjur (7). Our dietary diversity score equaled the number of food categories mentioned (excluding certain calorically dense categories such as rich desserts, salty snacks, soft drinks, concentrated sweets, and fats) plus the number of "other foods" (up to 5). The maximum diversity score was 20-15 specified food cate.gories plus 5 other foods. The dietary diversity score does not directly assess the nutritional value of a diet. However, we consider high scores to be associated indirectly with nutritious diets because high scores indicate that the child consumed a wide variety of foods. Our dietary quality scoring system awarded 1 point for each of the Four Food Groups for which the ques-tionnaire data indicated that the recommended number of servings had been consumed, plus 1 point each for consumption of good sources of vitamin C, and vitamin A/folic acid. We pilottested the instrument, and validity and reliability were confirmed as reported earlier (5). We telephoned 10% of nonrespondents in all groups to obtain their food records and found no differences in any groups between respondents and nonrespondents. To validate our findings we solicited a second day's intake from a random group of respondents; again, we found no differences. Results of the original analyses of the returned food records showed that the children in the SPI group had both higher dietary diversity and dietary quality scores than did students in the SI group. And the scores for this latter group were higher in both categories than the scores of the control group students (Table 1). Vegetables were the only individual food group to show a significant difference between the subject groups. We concluded that the parents of the SPI children were providing a wider selection of foods in the home, and this behavior could probably be attributed to the parent education variable. PROCEDURE AND FINDINGS For this study, we used the original class lists and contacted the school district office to locate the students JOURNAL OF NUTRITION EDUCATION
203
Table 1. Mean scores for reported food consumption scores at the conclusion of the nutrition education program (Study I)
Mean Scores 1
Category
Maximum Score
Dietary quality Dietary diversity Meats/poultrylfish Fruits Juices Vegetables Milk/milk products Cereals
6 20 6 7 5 7 5 5
Student and Parent Instruction (n
=
Student Instruction
51)
(n - 50)
5.35" 12 .29" 3.14 3.02 2.02 3.57" 2.55 2.26
4.71b 11 .08 b 2.47 2.89 1.76 3.08" 2.31 2.36
Control (n
=
50)
4.24c 1O.18c 2.58 2.66 1.62 2.46 b 2.24 2.22
lWithin each horizontal row, means bearing different superscript letters are significantly different (p :5 .05).
who still resided in the area. We mailed the same food questionnaire used in the first study, along with a letter of explanation, to the parents of 275 (78%) of the original sample of 352 students. The form was completed by the parent in consultation with the student (Note 2). In 1980 the response rate was 151 (43%); our response rate this time was 111 (41 %). We scored the returned food records for dietary diversity and dietary quality, and for total foods within six groups: meat, poultry, and fish; milk products; vegetables; fruits; juices; cereals. We used analysis of variance to identify differences between groups, and when differences occurred we used a Duncan multiple-range test to identify the locus of difference (8) . The analyses showed that after five years, in general, the participants in the SPI group were eating a higher quality diet than the participants in either of the other groups (see Table 2). The dietary diversity
score, which had shown a significant difference in the earlier study, did not prove to be significantly different among the three groups. The diversity mean scores did, however, tend to show a difference between groups when parent nutrition education had been conducted, and this tendency reached levels of significance when the number of foods within individual food groups was examined. In looking at the number of vegetables, milk, and milk products that each group was consuming, we found that compared to the other groups the SPI participants were consuming significantly (p :5 . . 01) greater quantities of these foods. Cereals were also reported to be consumed in greater variety by this group (p :5 .05). It is interesting to note that the values for meat/poultry/fish as well as juices approach significance similar to the aforementioned two groups. Because caloric requirements change during adolescence, we also analyzed the data for differences be-
Table 2. Mean scores for reported food consumption (Study II)
Mean Scores 1
Category
Maximum Score
Dietary quality· Dietary diversity Meats/poultry/fish Fruits Juices Vegetables· • Milk/milk products·· Cereals·
6 20 6 7 5 7 5 5
Student and Parent Instruction (n = 48)
4.54" 9.50 2.88 2.38 1.92 3.50" 2.77a 2.50"
Student Instruction (n = 30)
3.47 b 10.77 2.23 2.20 1.47 2.27b 1.93 b 1.70b
Control
F
(n = 33)
Probability
3.94 8.76 2. 33 2.09 1.45 2.24b 2.03 b 1.90b
.0034 .3200 .0657 .5630 .0618 .0005 .0009 .0196
lWithin each horizontal row, means bearing different superscript letters are significantly different . An "*,, indicates significant differences between groups at the .05 level, and ,, * *" indicates significant differences between groups at the .01 level.
204
JOURNAL OF NUTRITION EDUCATION
VOLUME 18
NUMBER 5
1986
tween ages and sex, but we found no significant differences. We found that in almost every case, for all groups, the mean number of foods within individual groups was higher than it was five years ago. This undoubtedly was a result of the total increase in calories being consumed as the children grew older, as well as the fact that the children were eating a greater number of foods. We made the general assumption that the serving sizes increased somewhat for all foods in all groups and thus did not affect the findings.
DISCUSSION AND IMPLICATIONS Inclusion of the parent nutrition education component was time consuming and required additional effort and money. But the effects have shown that this aspect was most valuable and worthwhile. Over the intervening years we have received numerous comments and compliments from parents who were part of the program, and we strongly believe parent education can be the most important contribution of a school nutrition program. Limitations. One of the most interesting and certainly most uncontrollable aspects of the present study is the ages of the participants. Although family control of available food is almost total in early school years, we know it diminishes as adolescence approaches and that as children grow older they consume more foods away from home (9-12). Still, we hope that the effects of early nutrition education in terms of selecting nutritious food will be sustained throughout the age of psychological separation from parents, and that peer pressure will develop in favor of nutrient-dense foods. The overall dietary diversity score for the 24-hour recall period was not significantly different among the three groups, but the food-group analyses showed that a wider variety of foods was probably available in the homes in which parents as well as children had received nutrition education. In this study, participants' reported food choices appear to reflect the effects of the early nutrition education only when the parents concomitantly received nutrition education. While the records received from the home represented only a one-day intake, the validity of one-day recalls has been documented (10); and Young (11) has reported on the acceptability of groups means. Still, we cannot deny that access to foods outside the home occurs frequently, and that good nutrition is not highly valued among this age group. As one mother rather succinctly noted on her questionnaire: "Her diet would be better if only she weren't 13."
VOLUME 18 NUMBER 5
1986
Nutrition knowledge. Many studies in nutrition education have shown that cognitive scores almost always increase as a result of nutrition education programs (3,13). However, until recently, there has been little or no evidence of a relationship between nutrition knowledge and food behavior; the evidence of such a relationship has been particularly lacking in the results of studies of older children (13, 14). However, since recent meta-analysis of nutrition education programs has shown positive relationships between knowledge and food intake (15), such an analysis would have been an interesting addition to this study. Unfortunately, we were unable to test the students because they had been dispersed into a multitude of other classrooms, including a rotating junior high school classroom. On the other hand, we are certain that after the termination of the initial study there was no further parent nutrition education of these groups. Since the first author has been the ongoing nutrition consultant for the school district in which our study was done, we are aware of the nutrition education activities within the district. And after the termination of the initial study, nutrition education efforts were directed toward an entirely different segment of the accessible population.
Conclusion. When the parents were involved in the nutrition education program, a number of things happened. Within these families, there was learning early in life as well as an increase in knowledge and development of positive attitudes toward nutrition. Evidently the parents integrated the nutrition information they received into family food purchasing and meal preparation practices. Not only were nutritious foods available, but proper preparation as well as parent modeling of consumption of nutritious foods were also demonstrated. Thus, good nutrition is probably valued more highly now by both these children and their families. On the other hand, when the parents were not involved in the nutrition education program, we could not discriminate between the food behavior of the students who had nutrition education and those who did not. Although our sample was small, the initial population sample after a five-year delay provided evidence that by itself early nutrition education in school will not provide enough motivation to dictate behavior that will result in a better quality diet in pre- and early adolescence. It appears that the effects of early nutrition education in terms of food behavior are better when parents also receive nutrition information, and that the effects will probably not be sustained unless this factor is included.
JOURNAL OF NUTRITION EDUCATION
205
Finally, we recommend more research in this area. Longer studies that include several strategies and correlate behavior with changes in knowledge and attitudes are necessary. 0 NOTES 1 The first author developed the food-frequency recall, which is available upon request. 2 The Human Subjects for Research Committee at California State University, Chico, approved this study.
UTERATURE CITED 1 Ullrich, H. Towards a national nutrition education policy. Journal of Nutrition Education 1:8-10, 1969. 2 American Dietetic Association. Position paper on child nutrition programs. Journal of the American Dietetic Association 64:520-21, 1974. 3 Smith, H. M., and C. L. Justice. Effects of nutrition programs on third grade students. Journal of Nutrition Education 11:92-95, 1979. 4 Yperman, A. M., and J. Vermeersch. Factors associated with children's food habits. Journal of Nutrition Education 11:72-76, 1979. 5 Kirks, B. A., D. H. Hendricks, and B. W. Wyse. Parent involvement in a nutrition education program for primary grade students. Journal of Nutrition Education 14:137-40, 1982.
6 Mahan, L. K., and J. M. Rees. Nutrition in adolescence, St. Louis: C. V. Mosby Co., 1984, pp. 24-33. 7 Caliendo, M. A., and D. Sanjur. The dietary status of preschool children: An ecological approach. Journal of Nutrition Education 10:69-72, 1978. 8 Nie, N. H., C. H. Hull, J. G. Jenkens, K. Steinbrenner, and D. H. Bent. Statistical packages for the social sciences, 2d ed. New York: McGraw-Hill Book Co., 1975, pp.409-24. 9 Schorr, B. C., D. Sanjur, and E. C. Erickson. Teenage food habits. Journal of the American Dietetic Association 61:415-20, 1972. 10 Gersovitz, M. J., P. Madden, and H. Smiciklas-Wright. Validity of the 24-hour recall and seven-day record for group comparison. Journal of the American Dietetic Association 73:48-55, 1978. 11 Young, C. M. et al. A comparison of dietary study methods. I. Dietary history vs. 24-hour recall. Journal of the American Dietetic Association 28:218-21, 1952. 12 Bass, M. A., L. Wakefield, and K. Kolasa. Community nutrition and individual food behavior. Minneapolis: Burgess Publishing Co., 1979, pp. 82-85. 13 Lindholm, V. W., J. Touliatos, and M. F. Wenberg. Predicting changes in nutrition knowledge and dietary quality in ten- to thirteen-year-olds following a nutrition education program. Adolescence 19:367-75, 1984. 14 Byrd-Bredbenner, C. et al. Junior high home economics curriculum: Its effect on students' knowledge, attitude, and behavior. Home Economics Research Journal 11:123-33, 1982. 15 Axelson, M. L., T. L. Federline, and D. Brinberg. A meta-analysis of food and nutrition-related research. Journal of Nutrition Education 17:51-54, 1985.
DAIRY PRODUcrS AND PLASMA UPOPROTEIN LEVELS IN VEGETARIANS Vegetarians who habitually consume a diet that is low in fat and high in carbohydrate exhibit lower low-density lipoprotein (LDL) levels than nonvegetarians. Sacks and his colleagues (Journal of the American Medical Association 254:1337-41,1985) set out to determine the influence of fat ingestion from dairy products on the lipoprotein levels of lactovegetarians. To do this, researchers compared the lipoprotein levels of lactovegetarians with lipoprotein levels of vegetarians who consume no animal products. Dairy products were the major sources of saturated fat and cholesterol in the diets of 75 adult lactovegetarians studied. Twenty-eight percent of their calories were derived from fat, with a polyunsaturated-to-saturated ratio (PIS) of 1.0. In spite of the fact that they attempted to abstain from consuming all types of animal products, the strict vegetarians consumed dairy products on an average of three times a month. Their diets averaged 15% of calories as total fat, with a PIS ratio of 2.5. Mean total cholesterol, LDL, and high-density lipoprotein (HDL) levels of the lactovegetarians were 21 %, 24%, and 7% higher, respectively, than those of the strict vegetarians. The LDLlHDL ratio was 18% higher in lactovegetarians than in strict vegetarians, reflecting perhaps a greater sensitivity of LDL levels than HDL levels to the ingestion of fat from dairy sources. Considering available data both from epidemiological studies and from clinical trials, the investigators conclude that current recommendations to lower saturated fat and cholesterol intake, while increasing consumption of carbohydrate, will produce a relatively selective lowering of the LDL level while producing little, if any, decrease of the HDL level. 206
JOURNAL OF NUTRITION EDUCATION
VOLUME 18
NUMBER 5
1986