The effect of a worksite nutrition education program on eating behaviors and blood lipids

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The purpose of the program was to determine if a 4-week group nutrition education series held at the worksite, focusing on eating behaviors can positively affect dietary behaviors that are associated with risk of chronic disease(s) related blood lipid parameters. Thirty-five employees (21 female, 14 male) participated. Before and after the program all participants completed fasting bloodwork (total cholesterol, TC; low-density lipoprotein cholesterol, LDL-C; high density lipoprotein cholesterol, HDL-C; triglycerides, TG) and diet records. The nutrition education program consisted for four 50-minute sessions given weekly during the lunch hour. Each class contained an activity to assess application of information presented. Class topics included cardiovascular disease risk factors, balanced diet, eating out, and label reading. The results showed non-significant decreases in lipid values and dietary cholesterol and fat intake along with increased intake in fruits and vegetables for the group. Males were observed to decrease (p<.05) TC and TC/HDL-C values along with servings of fat per day. The increase in HDL-C, and fruit and vegetable consumption was also significant for the males. Females significantly increased vegetable and fruit consumption. The results of this short-term worksite nutrition education program suggest that positive changes in eating behaviors and blood lipid levels can be achieved by focusing on dietary behavior changes independent of prescribed, stringent diets.
Program Rationale

In recent years, the public has been confronted with much information on diet and its association with chronic disease(s). The evidence is very strong for atherosclerotic cardiovascular diseases and hypertension and is highly suggestive for certain forms of cancer (National Research Council, 1989).

The worksite provides an opportunity to teach individuals about the relationship between diet and health. Nutrition programs conducted at the worksite have primarily addressed weight control and cholesterol reduction (Glanz & Sewald-Klein, 1986) with outcome measures limited to improvements in blood lipid levels and increased knowledge and awareness (Spilman, Goetz, Shults, Bellingham, & Johnson, 1986; Rose, Heller, Pedoe, & Christie, 1980; Quigley, 1986; Masur-Levy, Tavris, & Elsey-Pica, 1990; Bruno, Arnold, Jacobsen, Winick, & Wynder, 1990). While the reports of nutrition education programs that focus on eating behaviors are limited (Baer, 1993; Hartman, McCarthy, & Himes 1993), the existing information does suggest that nutrition education programs that focus on eating behaviors and specific food choices are related to improvements in blood lipid profiles.

The purpose of the present program was to determine if a 4-week group nutrition education series held at the worksite, focusing on eating behaviors, can positively affect dietary behaviors that are associated with risk of chronic disease(s) and lipid parameters.
Methods
Subjects

The nutrition education program was held on site at a large (> 800 employees) company in Cincinnati, OH. The program was sponsored by the Employee Health Division of the company. While the program was open to all employees, enrollment was limited to the first 35 participants who met the criteria for participation. Criteria for participation excluded individuals who were on prescribed lipid-altering medication, hormone therapy, or had fasting triglycerides above 200 mg/dl.

Of the 60 participants who expressed interest in the program, 35 employees (21 females, 14 males) were selected. The ages of the group ranged from 26 to 62 years (males=26-56 yrs, mean age 40.7+2.8 yrs; females=26-62 yrs, mean age 43.9+2.6 yrs).
Procedures

Before and after the nutrition education program all subjects participated in fasting blood work and completed diet records.
Bloodwork

All blood was drawn on site by a consulting laboratory phlebotomist. Participants were instructed to fast (including omission of all types of coffee) the 12 hours prior to blood draw and to refrain from consuming alcohol 24 hrs before blood draw. The blood was drawn twice within 14 days prior to the onset of the program, and 1 week after the last class of the program. Blood draw was conducted at the same time for each individual pre and post program.

The blood was enzymatically analyzed for total serum cholesterol and triglyceride (Alliance 580). High-density lipoprotein cholesterol (HDL-C) was measured using the heparin-manganese precipitation method as described by Warnick and Albers (1978). Low-density lipoprotein cholesterol (LDL-C) was estimated according to the formula of Friedewald, Levy, and Fredrickson (1972) in which LDL-C is equal to total cholesterol minus HDL-C and one-fifth of the total triglyceride value. The average of the two initial samples was used as participant's representative value.
Dietary Analysis

A 3-day diet record was completed prior to each blood draw. Instructions were provided on how to complete the diet record. Subjects were asked to write down all foodstuffs and beverages consumed for 3 consecutive days prior to blood draw. Food models and a food proportion handout sheet were used to illustrate serving sizes. The diet records were analyzed using the Nutritionist III software package (version 5.0, 1989, N-Squared Computing, Silverton, OR). The pre-program diet records were analyzed together. Foods were entered in their constituent parts. For example, scrambled eggs were not entered as such; rather, 2 eggs, 1 Tbsp 2% milk, and 1 Tbsp. butter were entered to obtain specific amounts and types of fatty acids consumed. Diet records were analyzed and averaged for daily total calories, dietary cholesterol, fat, dietary fiber, and percent of calories from protein, carbohydrate, and fat, respectively. Foods were also analyzed according to the Exchange Lists by Franz et al. (1986) to provide information on average number of servings from the food groups.

Program DesignThe development of the program was based on the assumption that most people in the intervention have been exposed to some of the dietary information on reducing risk of chronic diseases, specifically cardiovascular disease, but were lacking the knowledge to apply such information. The learning objectives for the program were to increase knowledge and apply recommendations. A limitation to the program is that level of diet and health related knowledge was not determined before the intervention.

The nutrition education program consisted of four 50 minute sessions given weekly during the lunch hour. The classes were taught by graduate students in Nutrition Education. Each class contained an activity to assess whether participants could apply the information presented. During the activity time, participants were encouraged to speak to the program leaders individually for further clarification and personalization of the information presented. Thus, the format of the sessions allowed for knowledge, self-monitoring, support, and self-efficacy. These attributes are among those listed by McCann, Retzlaff, Dowdy, Walden, and Knopp (1990) as being necessary to promote dietary behavior changes. The four classes were as follows:

Class 1: Risk factors associated with cardiovascular disease. Definition and description of blood lipid parameters and their role in cardiovascular disease. Desirable dietary distribution of macronutrient intake (fat, carbohydrate, and protein) and dietary cholesterol intake.

Activity: Cholesterol/Cardiovascular Disease Crossword Puzzle.

Class 2: Balancing the diet. Using their own dietary exchange pattern, participants were instructed on how to modify their eating patterns to be in accord with the Dietary Guidelines using the American Dietetic Association's A Guide to Variety (1988) and Food Pyramid (USDA, 1993) Handout(s). Participants were also instructed to list suggestions as to how they could incorporate such changes into their regular eating pattern, e.g., keep fruits and vegetables in the house, write a menu, pack lunch, etc.

Activity: Draw your pyramid. Participants were asked to draw a pyramid which reflected their current food group(s) intake, and one reflecting their dietary changes.

The Lunch Bag Game. Participants were provided with different lunch bags which contained an assortment of foods (food models) often consumed at lunch. Participants were asked to evaluate the meal(s) based on recommended food group intake.

Class 3: Balanced diet in a busy life. How to incorporate eating out and fast food menus into a balanced diet. Quick meal ideas. Tips for reducing fat intake. Examples of how to be a low fat eater in a high fat world. Local restaurants and fast food chain menus were used as examples.

Activity: Menu modification. Participants were provided with a variety of fast food menus and asked to make selections based on food group variety and fat content of foods. Participants were asked to suggest substitutions/changes in preparation to decrease total fat intake.

Class 4: Label reading and nutrient density. The new food label was explained along with the concept of nutrient density relative to fiber, mineral, and vitamin content of foods. The concept of counting fat grams was introduced.

Activity: Evaluating a food label for content of macro- and micronutrients, including fiber. Evaluating claims on food labels based on nutrient information. Calculating the percent of total calories and grams of macronutrients (protein, carbohydrate, and fat).

Statistical Analysis and Evaluation The nutrition education program served as the independent variable. Dependent variables included the lipid evaluations and dietary evaluations conducted before and after the nutrition education program. There was no control group. Subjects served as their own control. An evaluation was completed at the end of each session and an overall program evaluation was completed at the follow-up blood draw.

Data were analyzed by a two-tailed t-test to determine the differences between pre- and post- intervention values for blood lipid parameters and eating patterns. Data were analyzed by group and by gender. The level of significance was set at p<.05.
Results

Attendance at the nutrition education sessions averaged 95%. Evaluations from each session indicated that all participants at the session believed the information presented to be accurate and relevant. However, it was the related activities that were reported to be most useful by the majority of the participants. The average score on the activities was 100%, indicating that participants could accurately apply the information that was presented.

Overall group results showed non-significant decreases in blood lipid values (TC, LDL-C, TG, TC/HDL-C) and dietary intake of cholesterol and total fat (Table 1). Dietary intake of fiber increased along with number of servings of fruits and vegetables.

The females (Table 2) showed a significant increase in vegetable and dietary fiber consumption. The increase in fruit consumption approached significance. The males (Table 3) showed a significant decrease in TC and TC/HDL-C. The increase in HDL-C was significant. Number of servings of fat/day significantly decreased while servings of vegetables and fruit/day increased.
Table 1
Results for the Group

Variable Pre-test Post-test

Weight (lbs.) 176.9+7.1 176.9+7.0
TC (mg/dl) 250.2+5.24 245.7+5.19
LDL (mg/dl) 167.3+4.43 164.7+4.31
TG (mg/dl) 168.7+15.17 154.5+15.39
HDL (mg/dl) 49.9+2.06 50.2+2.00
Ratio
(TC/HDL-C) 5.24+0.23 5.24+0.20
Calories (kcal/d) 1790.5+108.0 1655.9+79.4
D.Cholesterol (mg/dl) 214.9+28.8 203.8+26.1
Fat (g/d) 60.8+4.4 54.4+3.8
Dietary Fiber (g/d) 12.7+1.2 15.3+1.5
Fat (%) 30.4+0.01 29.2+0.01
Protein (%) 17.0+0.01 19.3+0.01
Carbohydrate (%) 52.9+0.1 53.2+0.02

Dietary Exchange List Values

Milk 0.95+0.21 0.86+0.16
Vegetable 1.5+0.18 2.5+0.63
Fruit 2.2+0.40 2.4+0.43
Bread 8.9+0.56 9.1+0.57
Meat 5.7+0.59 6.0+0.47
Fat 9.6+0.78 8.3+0.65

Discussion

The results of the 4-week nutrition education program suggest that a short-term worksite nutrition education program unaided byprescribed dietary restrictions can positively influence dietary behaviors and blood lipids in a mixed gender group.

Statistical significance may not have been achieved for the group due to the short length of time between pre- and post- intervention bloodwork and differences in eating behavior changes among gender groups. Participation in the 4-week Heart Tune Program (Groth, Kirk, & Alvin, 1991) were able to achieve a significant decrease in blood lipid levels with 4 weeks of intervention. However, each session was 2 1/2 hours each week and the time between pre- and post- bloodwork was unknown and varied for each participant. Also, the participants were asked to follow the American Heart Association Step 3 Diet for 2 weeks prior to the last blood draw which made it impossible to tell if the changes in blood lipids were due to the educational intervention or a very restrictive diet.
Table 2
Results for Females

Variable Pre-test Post-test

Weight (lbs.) 171.6+10.3 172.0+10.1
TC (mg/dl) 258.8+7.42 258.1+7.01
LDL (mg/dl) 168.5+7.10 167.7+6.56
TG (mg/dl) 187.5+25.03 183.6+24.8
HDL (mg/dl) 54.1+3.11 53.6+3.15
Ratio
(TC/HDL-C) 5.07+0.39 5.04+0.34
Calories (kcal/d) 1567.4+91.0 1499.4+84.7
D.Cholesterol (mg/dl) 175.8+26.1 177.4+32.6
Fat (g/d) 57.3+4.9 52.9+5.0
Dietary Fiber (g/d) 10.1+1.0 13.7+1.4*
Fat (%) 32.2+0.01 30.8+0.02
Protein (%) 17.6+0.01 19.7+0.01
Carbohydrate (%) 50.4+0.02 51.6+0.02

Dietary Exchange List Values

Milk 0.76+0.17 0.59+0.20
Vegetable 1.3+0.19 2.1+0.35*
Fruit 1.7+0.19 2.1+0.35
Bread 7.5+0.52 8.2+0.53
Meat 5.4+0.67 5.7+0.45
Fat 9.0+0.91 8.1+0.91

*p<.05

When data were analyzed by gender, the males in the present study were, however, observed to significantly decrease serum cholesterol levels and TC/HDL-C ratios. This may be due to the significant changes in fat consumption observed. The males decreased fat consumption by 9.5 g/d (approximately two times more than the women) and decreased dietary cholesterol intake by 60.3 mg/d. The males achieved their reduction in dietary fat and cholesterol intake by decreasing intake of butter (using less or substituting Molly McButter), switching to fat free dressings, eating smaller portions of beef, choosing leaner cuts of meat, substituting skinless chicken for beef, decreasing the number of eggs consumed. Such dietary factors have been identified as being important in decreasing cholesterol levels in men (Sharlin, Posner, Gershoff, Zeitlin, & Berger, 1992).
Table 3
Results for Males

Variable Pre-test Post-test

Weight (lbs.) 183.0+19.7 183.3+9.4
TC (mg/dl) 240.3+6.53 231.3+9.4*
LDL (mg/dl) 165.9+5.17 161.6+5.46
TG (mg/dl) 146.6+13.70 120.5+11.08
HDL (mg/dl) 45.0+1.89 46.2+1.75*
Ratio
(TC/HDL-C) 5.44+0.22 5.07+0.18**
Calories (kcal/d) 2125.2+201.9 1890.6+128.7
D.Cholesterol (mg/dl) 273.7+57.9 213.4+45.0
Fat (g/d) 66.1+8.2 56.6+5.9
Dietary Fiber (g/d) 16.7+2.3 18.7+0.01
Fat (%) 27.7+0.02 26.7+0.02
Protein (%) 16.0+0.01 18.7+0.01
Carbohydrate (%) 56.7+0.02 55.5+0.03

Dietary Exchange List Values

Milk 1.25+0.45 1.26+0.21
Vegetable 1.7+0.29 3.0+1.52*
Fruit 3.0+0.84 4.8+1.03*
Bread 11.0+0.98 10.3+1.11
Meat 6.1+1.01 6.3+0.97
Fat 10.5+1.41 8.6+0.90*

*p<.05
**p,.01

Changes in dietary behaviors observed for the females included the addition of fruit to the diet and increasing number of salads (vegetables) consumed. While meat intake remained about the same, leaner meats were consumed.

The differences in dietary changes made between the males and females may in part be explained by the cognitive learning theories which suggest that an individual's prior knowledge is a major factor in determining what can be learned (Auld et al. 1991). They reported that females had more misconceptions than men about fat and cholesterol. This could attribute to the males and females applying the information differently, i.e, different dietary behavior changes. An activity at the onset of the program that addressed nutrition myths or misconceptions, or a similar activity for each class topic is suggested as a way to facilitate discussion and dispel erroneous information.

The majority of the participants rated the last two classes higher than the first two classes, supporting their preference for skill acquisition. The first two classes were more informational relative to diet and disease prevention and addressed general dietary guidelines. Comparatively, the last two session addressed foods specifically.

Participants also expressed a desire for more classes. Some recent studies have shown that follow-up counseling can be effective in helping to decrease dietary risk factors associated with cardiovascular disease (Shenberger et al. 1992, Milkereit & Graves, 1992). Shenberger et al. further reported that dietary compliance is maximized by maintaining feedback and rapport. The classes of the program were designed such that they could be repeated independently of each other to reinforce eating behavior changes. Repeating classes, with varying activities, would allow for continued group discussion as well as individual attention and intervention.
Conclusions

Overall, the results of this short-term worksite nutrition education program suggest that positive changes in eating behaviors and blood lipid levels can be achieved by focusing on dietary behaviors independent of prescribed, stringent diets in individuals who are interested in modifying their dietary intake. The format of the program facilitated group and individual intervention in a very cost-efficient manner. To maximize application of information to support desirable dietary behaviors, it is recommended that the educational sessions also address misconceptions related to the topic(s) being presented.
References

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Bruno, R., Arnold, C., Jacobson, L., Winick, M., & Wynder, E. (1983). Randomized controlled trial of a nonpharmacologic cholesterol reduction program at the worksite. Preventive Medicine, 12, 523-532.

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Masur-Levy, P., Tavris, D.R., & Elsey-Pica, L. (1990). Cardiovascular risk changes in a work-site health promotion program. Journal of the American Dietetic Association, 90, 1427-1428.

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National Research Council, Committee on Diet and Health, Food and Nutrition Board, Commission on Life Sciences. (1989). Diet and health: Implications for reducing chronic disease risk. Washington, DC: National Academy Press.

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Sharlin, J., Posner, B.M., Gershoff, S.N., Zeitlin, M.F., & Berger, P.D. (1992). Nutrition and behavioral characteristics and determinants of plasma cholesterol levels in men and women. Journal of the American Dietetic Association, 92, 434-440.

Shenberger, D.M., Helgren, R.J., Peters, J.R., Quiter, E., Johnston, E.A., & Hunninghake, D.B. (1992). Intense dietary counseling lowers LDL cholesterol in the recruitment phase of a clinical trial of men who had coronary artery bypass grafts. Journal of the American Dietetic Association, 92, 441-445.

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Warnick, G.R., & Albers, J.J. (1978). A comprehensive evaluation of the heparin-manganese precipitation procedure for estimating high density lipoprotein cholesterol. Journal of Lipid Research, 19, 65-76.

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By Janine T. Baer, Brett Kugler, Carolyn Bachman-Wolff, The University of Cincinnati

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