A Nutrition Intervention to Increase Whole Grain Intake in College Students

This study aimed to improve whole grain (WG) intake and coronary heart disease risk factors in 98 college students through an intervention in campus dining halls. The exploratory aim was to evaluate the impact of text messaging on diet and coronary heart disease risk. The 6-week intervention consisted of WG and low-fat dairy messages in campus dining halls and text messages to a subsample (n = 26). WG intake, high-density lipoprotein cholesterol, body weight, and body mass index significantly increased over time. Total dairy intake decreased over time. Overall, the intervention had a positive impact on WG consumption and on high-density lipoprotein cholesterol.

tion's 2020 Strategic Impact Goals 9 and in the National Heart, Lung and Blood Institute's 2012 Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents. 10 Despite this emphasis on the importance of early prevention efforts, little has been done to address heart disease risk in young adults who are unaware 11 and have not been screened for CHD risk. 12 The few cross-sectional studies that have assessed CHD risk in college students ages 18 to 24 demonstrate the need for increased screening, risk assessment, and disease prevention interventions in this age group. [13][14][15][16] Burke et al 17 reported that more than 50% of college students have elevated low-density lipoprotein cholesterol (LDL-C), as many as 27% have elevated total cholesterol, and 47% have hypertension. 17 Similar studies have found that 18% have elevated triacylglycerides (TAG), 20% have low high-density lipoprotein cholesterol (HDL-C), 16 and 13% have elevated glucose. 18 These risk factors are strongly A Nutrition Intervention in College Students 223 correlated with the extent of atherosclerotic lesions. 19 Some studies have found that college students' diets are high in saturated fat 7 and low in whole grains, 6 which negatively affect these risk factors, especially LDL-C; as many as 70% exceed total and saturated fat recommendations. 7 College students also fail to meet whole grain recommendations, 6,20 consuming only 12% (0.37 oz) of the recommended minimum of 3 oz. 6 LDL-C concentrations can be improved by decreasing saturated fat and increasing whole grain consumption. 21,22 Because 42% of US young adults attend college or universities, 23 these campuses provide an ideal opportunity to target young adults at a point in life when lifestyle choices are being made and before disease progression occurs. 24,25 Previous research has demonstrated that increased awareness of healthy options through point-of-selection (POS) signage and benefit-based messages has increased the selection of healthier options in university dining halls. [26][27][28][29] Recently, technology has been used to promote behavior change in college students. [30][31][32][33][34] To the best of our knowledge, this is the first study to utilize both POS and text messaging in a nutrition intervention on a college campus. The purpose of this study was to increase whole grain consumption through a nutrition intervention in campus dining halls. A secondary aim was to improve CHD risk factors. An exploratory aim was to analyze the impact of a text messaging intervention on whole grain and low-fat dairy intake and CHD risk factors in a subsample of participants.

Design
A single-group design was used to assess the impact of a whole grain and low-fat dairy intervention on CHD risk factors. Baseline and postintervention assessments were conducted in the fall semester immediately before and after the 6-week intervention. The follow-up assessment occurred in the spring semester 6 months after the baseline assessment. A subsample (n = 26) was recruited for additional measures. All measurements described were obtained at baseline, postintervention, and follow-up.

Sample
Classroom announcements were used to recruit students from large general education courses at a medium-sized northeastern university. Eligibility criteria were age (18-24 years), having a campus meal plan, and a body mass index (BMI) 18.5 kg/m 2 or more. Of the 1434 students who were invited to participate, 170 completed the initial screener but 13 of these were ineligible because of age and BMI. Other exclusion criteria included being pregnant or lactating, or self-report of one of the following conditions: eating disorder, liver disease, bleeding disorder, diabetes, cancer, or CHD; however, none of these were reported. Of the 157 eligible students, 59 failed to schedule or attend baseline assessment visits, resulting in a sample of 98 students who completed baseline assessments. A subsample was recruited for additional measures including 24-hour dietary recalls based on responses to the green eating stage of change question from the Green Eating Questionnaire. 35 Eligible participants were in the precontemplation, action or maintenance stages of change according to the Transtheoretical Model. Twenty-six students consented to participate in the exploratory subsample measures. All participants read and signed an informed consent approved by the University's Institutional Review Board.

Dietary intake
The National Health and Nutrition Examination Survey 2009 to 2010 National Cancer Institute Dietary Screener Questionnaire (NCI Screener) was used to assess intake of fruits and vegetables, dairy/calcium, whole grains/fiber, added sugars, red meat, and processed meat in all participants. 36

TOPICS IN CLINICAL NUTRITION/JULY-SEPTEMBER 2016
Purchasing records from dining services were used as a proxy for whole grain and lowfat dairy consumption. Purchasing records were obtained for bread and dairy products that offered a whole grain or low-fat dairy alternative (bread, rolls, breadsticks, English muffins, milk, and yogurt) to determine whether students selected the whole grain or low-fat dairy option. Purchasing records were a viable estimate for consumption as dining services indicated that because of the highly perishable nature of these items; what is ordered is what gets consumed. Purchasing records were obtained at baseline, throughout the intervention, postintervention, and 6-month follow-up. Average values were calculated for individual items at each time point and were used for the analyses.
Twenty-four-hour dietary recalls were collected and analyzed for the subsample of participants (n = 26) using the multiple-pass method in conjunction with the Nutrition Data System for Research (NDS-R) software (University of Minnesota, Minneapolis, Minnesota) version 2012. All participants completed three 24-hour dietary recalls: 1 in-person and 2 over the phone on 3 nonconsecutive days (including 2 weekdays and 1 weekend day). 37,38 Nasco food models (eNasco, Fort Atkinson, Wisconsin) and food amounts booklets were available during the initial in-person 24-hour recall to more accurately estimate portion size. 39 Participants were given the booklets after the initial recall for the phone recalls. The mean values of the 3 recalls provided dietary data for analysis. Healthy Eating Index 2010 scores were calculated from the mean values from the three 24-hour recalls to assess diet quality in the subsample of participants (n = 26).

Biochemical
After a 12-hour fast, finger sticks were performed on all participants to obtain blood samples for determination of blood lipid and glucose concentrations. Finger sticks were performed by trained study staff. Values for LDL-C, total cholesterol, TAG, HDL-C, and glucose were obtained using Cholestech LDX tabletop analyzers (Cholestech, Hayward, California).

Anthropometrics
Height was measured to the nearest 0.1 cm using a Seca 220 stadiometer (Seca Corporation, Hamburg, Germany). Weight was measured to the nearest 0.1 kg using a calibrated digital Seca 769 scale (Seca Corporation, Hamburg, Germany). Measurements were taken in duplicate and the average of the 2 values was used for the analysis. BMI was calculated using the following formula: weight in kilograms/height in square meters. Waist circumference was measured in duplicate at the top of the iliac crest upon exhalation to the nearest 0.1 cm using a Gulick fiberglass, nonstretchable tape measure with an attached tensometer (Patterson Medical, Mount Joy, Pennsylvania). The average of the 2 values was used for the analysis.

Blood pressure
Blood pressure was measured after a 5-minute seated rest period using an automatic blood pressure monitor with arm cuff (Omron HEI-711, Omron Health Care Products, Issaquah, Washington). Measurements were retaken 2 minutes apart until values were within 2 mm Hg. The average of the 2 values in agreement was used for the analysis.

Intervention
All 98 participants were exposed to a 6-week intervention, which consisted of benefit-based nutrition messages in the 2 student campus dining halls at the university. Students with meal plans were able to eat at either dining hall; all students who ate at the dining halls were exposed to the intervention. Sample messages included: "Make the switch to whole grain breads and wraps to stay full longer" and "Maintain a healthy weight . . . choose low fat dairy." Messages were displayed on television monitors and on POS signs at the deli and dairy stations in the 2 main dining halls. Messages were visible throughout the day and new messages were displayed each morning (Monday through Copyright © 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Friday). A total of 5 whole grain messages and 5 low-fat dairy messages were developed by a team of 6 registered dietitians. Messages were repeated after the initial Monday through Friday sequence for reinforcement.
Prompts to choose whole grain bread were also verbally provided by the deli station staff in both dining halls. These standard prompts were given to all students who visited the deli station. In addition, nutrition education booths to promote whole grain and low-fat dairy consumption were positioned in a high-traffic area outside dining hall 1 only (because of space constraints in dining hall 2). Message and booth content alternated between whole grains and low-fat dairy each week. Whole grains and low-fat dairy were promoted for a total of 3 weeks each for a total intervention period of 6 weeks.
Message and booth content addressed specific motivators of healthy eating (increased energy, healthy body weight, and staying full) from 9 previously conducted focus groups that addressed motivators and barriers to healthful eating in buffet-style dining halls. 40 In addition, the subsample of participants received the same nutrition message that was displayed on the television monitors in the dining halls each weekday via text message or e-mail, depending on their preference. Google Voice (Google, Mountain View, California), a web-based application, was used to deliver text messages. A postintervention online survey was administered to solicit feedback on the preferred method of message delivery.

Analysis
Descriptive statistics were performed and skewness and kurtosis were examined to determine data distribution. Nonnormally distributed data were transformed. BMI, LDL-C, total grains, low-fat dairy, and soluble fiber were log transformed. Triacylglycerides and sugar-sweetened beverages (SSBs) were square root transformed. Whole grains, semiwhole grains, total fiber, reduced fat dairy, glucose, and systolic blood pressure were analyzed using nonparametric tests. Continuous variables were expressed as mean ± stan-dard deviation and categorical variables were expressed as frequencies. Repeated-measures analysis of variance with post hoc tests using the Bonferroni adjustment were used to determine whether there were significant differences over time. The Friedman test with post hoc Wilcoxon signed rank tests using a Bonferroni-adjusted α value was used to assess differences over time for whole grains, semi-whole grains, fiber, and glucose. Mixed between-within analysis of variance assessed differences between groups over time. Chisquare tests were used to analyze categorical variables. Statistical significance was set at P < .05 for all tests.

Participants
Participant characteristics at baseline are presented in Table 1. The majority of the sample was female (78%) and white (81%). The mean age was 18.2 ± 0.6 years. At baseline, more than 50% of females and 36% of males had low HDL-C for gender (<40 male, <50 female mg/dL), 19% had elevated LDL-C (≥100 mg/dL), 14% had elevated TAG (≥150 mg/dL), and 13% had elevated systolic blood pressure (≥130 mm Hg). More than 80% of the sample had never or were unsure as to whether they ever had their cholesterol checked. Sixtythree participants completed all 3 assessment visits and 18 of these 63 completed additional measurements for subsample analyses. There were no differences in dietary variables or CHD risk factors by attrition status except for TAG (data not shown). Completers (n = 63) had higher TAG at baseline compared with noncompleters (n = 35).

Whole grain intake
As shown in the Figure, data from the NCI Screener indicated that whole grain intake increased over time (P = .005). Whole grain intake increased from baseline to follow-up (0.8 ± 1.1 oz to 1.1 ± 1.5 oz, P = .008) and from postintervention to follow-up (0.8 ± 0.8 oz to 1.1 ± 1.5 oz, P = .006). Purchasing record data (used as a proxy for consumption) indicated that percent whole grain con-sumption doubled (12.7%-23.9%) in dining hall 1 during the 6-week intervention (data not shown). In dining hall 1, baseline whole grain consumption was significantly lower than the intervention and follow-up period but not different from postintervention. In dining hall 2, whole grain consumption significantly increased across baseline, postintervention, and follow-up periods. Dining hall 2 had significantly higher whole grain consumption compared with dining hall 1 at all time points.

Dairy intake
There was no primary measure of low-fat dairy intake. However, purchasing records used as a proxy for dairy intake indicated  that nonfat dairy intake increased by 3% to 4% during the intervention and was significantly higher at follow-up compared with other time points in dining hall 1 (data not shown). Data from the NCI Screener showed that total dairy intake decreased over time (P = .003, η 2 = 0.15). SSB also significantly decreased over time (P = .005, η 2 = 0.14).
Twenty-four-hour recall data showed no changes in total grain, semi-whole grain, refined grain, fiber, total dairy, full-fat dairy, reduced-fat dairy, low-fat dairy, or saturated fat intake in subsample analyses (P > .05). Energy intake significantly decreased over time (P = .014, η 2 = 0.42). Decreases in energy intake occurred from baseline to postintervention (1896.4 ± 553.3 kcal to 1658.0 ± 491.1 kcal, P = .009). There were no significant changes over time in overall diet quality as measured by the Healthy Eating Index 2010 (P = .39).
Mixed between-within analysis of variances comparing the general sample and the subsample indicated that there was a significant effect of time for HDL-C (P = .004, η 2 = 0.17) and total dairy (P = .024, η 2 = 0.10) but no significant differences existed between groups. There was also a significant effect of time and group for weight (time: P < .001, η 2 = 0.28; group: P = .033, η 2 = 0.07) and BMI (time: P = .001, η 2 = 0.20; group: P = .031, η 2 = 0.02). The mean values for weight and BMI were significantly greater in the subsample compared with the general sample at 228 TOPICS IN CLINICAL NUTRITION/JULY-SEPTEMBER 2016 each time point. Because of data distribution, a mixed between-within analysis could not be performed for whole grains.
A postintervention survey revealed that nearly 80% of participants noticed the messages. Seventy percent reported that the messages prompted them to choose whole grains, whereas only 40% indicated that the messages prompted them to choose low-fat dairy. POS messaging was perceived to be the most effective messaging delivery method for both whole grains and low-fat dairy.

DISCUSSION
The results of this study demonstrate that nutrition POS messaging in campus dining halls is an effective strategy to increase whole grain intake in college students. Improvements in HDL-C were seen. Declines in total dairy intake over time suggest that the focus of interventions should shift from low-fat dairy to total dairy, as this age group is failing to meet total dairy recommendations.
Whole grain consumption (as measured by the NCI Screener) increased by nearly 40% from baseline to follow-up. This is supported by the purchasing records, which indicated that percent whole grain consumption doubled during the 6-week intervention. It is also consistent with the findings from pilot testing in the spring of 2012 that showed a 12% increase in whole grains when messages were displayed in dining halls for 1 week. Although increases in whole grain consumption were observed, mean intake at follow-up still fails to meet recommendations. This is consistent with findings by Ha and Caine-Bish 6 that reported a significant increase in whole grain consumption from 0.37 to 1.16 oz in college students after a whole grain intervention embedded in a semester-long nutrition course. Despite this increase, whole grain intake after the intervention was more than 50%, less than the minimum recommendation of 3 oz. Similarly, a 2014 review of dietary interventions in college students also indicated that dietary changes made by this group are often minimal and not maintained. 41 Exploratory analyses on Heart Start II participants who received the additional text messages indicated that this subgroup had nonsignificant increases in their whole grain intake. This may be attributed to the small sample size in this subgroup analysis (n = 18).
Baseline CHD risk factor prevalence data were similar to previous cross-sectional estimates of CHD risk factors in this age group. [14][15][16]42 Despite this documented presence of risk factors in college students, there is a lack of research assessing the impact of nutrition interventions on CHD risk factors in college students. Spinler et al 7 reported no changes in total fat, saturated fat, or plasma cholesterol concentrations over a 3-month period after a nutrition and cardiovascular disease education in pharmacy students. Although there were no changes in LDL-C in the present study, there were improvements in HDL-C, and low HDL-C was the most prevalent risk factor in this sample of college students. The significant increase in HDL-C over time may be explained by the dietary changes, as increases in whole grains have been associated with improvements in HDL-C. 43 Weight gain during the first year of college is well documented. [44][45][46][47][48][49] Our sample gained less weight than has been previously reported in this age group. 47,48 Although weight status was not a primary aim of the intervention, the weight gain observed in this population highlights the need for weight gain prevention efforts in this age group. However, interventions focusing on weight must be sensitive to the higher prevalence of disordered eating in this age group. 50,51 Purchasing records showed a slight increase in nonfat dairy over time, but the NCI Screener indicated that total dairy intake decreased over time. Because this screener did not allow for the analysis of components of total dairy (reduced fat, low-fat, nonfat), it cannot be determined whether there was a shift to low-fat dairy over time. A decrease in total dairy, however, is consistent with previous findings 52, 53 and provides evidence for the need for additional efforts in this age group to prevent further declines in dairy intake. A reduction in dairy intake typically coincides with an increase in SSB as a result of displacement. 54 In this sample, however, SSB consumption significantly decreased along with dairy consumption over time. Decreased consumption of dairy at follow-up may be a function of weight-conscious eating behaviors that occurred prespring break in anticipation of beaches, as dairy is perceived to be "fattening." 26,55 Similarly, purchasing records at follow-up showed an increase in whole grain consumption, which may be a function of prespring break healthier eating.
Feedback on the individual intervention components revealed that POS messaging was the preferred method of messaging. POS messaging has previously been shown to be an effective nutrition strategy to promote healthy choices in college dining halls. 56 In a dining hall intervention that utilized signs, table tents, flyers, and benefit-based messages, college students reported increased awareness of healthy options as the primary reason for selecting healthier choices. 26 A major strength of this study was the use of multiple measures to assess dietary intake. To the best of our knowledge, this was the first study to use purchasing records to quantify intake in campus dining halls. An additional strength was the use of multiple methods of message delivery. Although previous studies have used text messaging as an intervention delivery method in this age group, [30][31][32][33]57 this was the first to use text messages to target dietary choices known to have a positive impact on CHD risk. Participant replies to text messages suggest that text messaging is an effective way to engage this age group.

Limitations
Despite these strengths, there were some limitations. The majority of the sample was freshmen, female, and white, limiting the extent to which results can be generalized to other populations. The high percentage of white participants was, however, consistent with the ethnicity makeup at the university (21% nonwhite). The low response rate was another limitation. The use of purchasing records as a proxy for consumption also has limitations. Items were chosen that dining services reported as having minimal waste, but plate waste could not be accounted for. Another limitation was the lack of a primary measure for low-fat dairy. In addition, the use of finger sticks for lipid determination may have introduced more error than standard laboratory methods, but this error is greatly reduced when performed by experienced personnel. 58

CONCLUSION
College campuses provide an ideal setting to promote healthier dietary choices. Targeting young adults at a point in their lives when lifestyle choices are being made presents an opportunity to influence lifelong eating habits and improve CHD risk factors in this population. Overall, findings from this study indicate that a nutrition intervention was effective in increasing whole grain intake in college students. This study demonstrates that relatively small environmental changes such as POS messaging in campus dining halls can positively impact dietary intake and improve CHD risk factors in college students. A concerted effort from health professionals, policy makers, dining hall managers, and oncampus restaurant owners is needed to create an environment that promotes the adoption of lifelong healthy behaviors. Future research should focus on implementing nutrition approaches to promote healthy eating on college campuses as cost-effective ways to guide students in making better dietary choices.