Abstract
BACKGROUND:
Worksite wellness programs have the ability to activate health promotion and stimulate behavior change.
OBJECTIVE:
To measure longitudinal associations between visits with a Registered Dietitian Nutritionist (RDN), as part of worksite wellness programs, on dietary and lifestyle behavior changes.
METHODS:
The study sample included 1,123 employees with 77 different worksite wellness programs across the United States from March to December 2017. Hierarchical linear modeling was used to evaluate the associations of RDN visits with behavior changes.
RESULTS:
The mean BMI at baseline was 33.48, indicating over half of all employees are considered obese. Employees who attended more than one visit showed an increase in whole grain consumption and corresponding weight loss (t-ratio = 2.41, p = 0.02). Age played a significant factor in the rise of systolic blood pressure; employees who attended more visits showed an increase in whole grain consumption and corresponding blood pressure (t-ratio = –2.11, p = 0.04).
CONCLUSIONS:
RDNs as part of worksite wellness programs, can contribute to improvements in lifestyle behavior changes. These data highlight the need for nutrition intervention at the workplace. Research on nutrition-focused worksite wellness programs is needed to assess the long-term health outcomes related to dietary and lifestyle behavior changes.
Background
Obesity is a major and costly public health epidemic, which affects more than 78 million American adults [1, 2]. Obesity results in a significant increase in medical disbursements and truancy among full-time employees [3]. U.S. companies lose an estimated $4.3 billion each year due to obesity-related absenteeism and loss of productivity [4, 5]. Obesity increased work productivity impairment in twelve different occupations between 7.3%to 19.3%when using the Work Productivity and Activity Impairment-General Health questionnaire. As such, indirect costs due to obesity were between $860 to $5,622 per year [6]. It is estimated that 16%to 18%of total U.S. healthcare costs will be directly ascribed to the overweight and obese by the year 2030, for a value of $860.7 to $956.9 billion [7]. Cawley et al. reported that adult obesity raised the annual medical care costs by $3,508 per obese individual, an estimated cost to the United States of $315.8 billion [4]. Furthermore, for every one unit increase in BMI medical and pharmaceutical costs rise by 4%and 7%[8]. Due to these extreme costs, employers are finding it imperative to their business success to improve the health of their employees.
Employer-sponsored wellness programs are one strategy for addressing employees’ chronic disease risk factors, promoting healthy lifestyles, and reducing employers’ healthcare costs. In 2013, 16%of employees reported having mandatory participation in employer wellness programs [9]. These worksite wellness programs are expected to improve employee health, therefore curb employer costs. However, the efficacy of said programs is still up for debate. A systematic review by Lerner et al., found that the economic impact of worksite wellness programs to be limited and inconsistent [10]. Similarly, van Dongen and colleagues examined net benefits, benefit-cost-ratio and return on investments in worksite wellness programs and reported that evidence on profitability to be inconclusive. The authors, however, noted that financial savings in terms of reduced absenteeism and medical costs were evident in the review of non-randomized control studies [11]. It’s been reported that lower average medical claim costs among participants enrolled in a worksite wellness program compared to non- participants [12]. Despite the inconsistency in the effectiveness of these programs, the prevalence of employer-sponsored wellness programs that target weight or BMI is expected to increase [13, 14].
The approach of the worksite wellness program has a great impact on the success of the program. There are various types of worksite wellness programs. A comprehensive worksite wellness program, focused on nutrition, physical activity and stress has been shown to have significant long-term impact on weight loss and weight maintenance in overweight and obese individuals [15]. Delivery of worksite wellness programs by trained professionals, including Registered Dietitian Nutritionists (RDN) has strong implications on the success of the program. For example, worksite wellness programs that included a dietitian, resulted in significant changes in biochemical, anthropometrics, fruit and vegetable intakes and improvements in other cardiometabolic risk factors [16–18]. RDNs are trained professionals in evidence-based nutrition interventions. Most worksite wellness initiatives include the use of nutrition to improve health. As such, RDNs provide a needed resource for many worksite wellness programs [19, 20]. Medical Nutrition Therapy delivered by RDNs is an effective tool for the management, prevention, or reversal of common metabolic conditions including prediabetes and type II diabetes, obesity, and other metabolic conditions associated with weight [21–23]. Although shown as effective treatment, few worksite wellness programs, and only in localized one-facility programs, utilized nutrition counseling from RDNs in their approach.
This study contributes to the literature by using hierarchical linear modeling to discover the associations between visits with an RDN with dietary and lifestyle behavior modification. This study is the first of its kind to analyze data from multiple companies across the country to describe the valuable impact from RDN-led worksite wellness programs.
Methods
Aim and objective
The primary aim of this study was to determine changes in dietary and lifestyle related factors after face-to-face counseling intervention(s) by a Registered Dietitian Nutritionist (RDN) as part of multi-site worksite wellness programs. It was hypothesized that the participants who returned for more than one counseling session would exhibit a statistically significant improvement in anthropometrics and dietary intake compared to baseline measurements.
Data
This study examined the retrospective association between dietitian visits, as part of worksite wellness programs, and self-reported behaviors from March 2017 to December 2017. De-identified individual-level employee data was obtained, and then cleaned by an investigator on the study team. The study population was limited to a cohort of 2,705 employees, of which only 1,123 had follow up visits, who were employed by one of the participating worksite wellness locations. Each company had a varied composition of their respective worksite wellness programs, some including a range of opportunities beyond consultations with a registered dietitian nutritionist (e.g. body composition testing, annual physical, smoking cessation programs, online health databases). Participants were unequally distributed across 77 employers from various industries and locations across the United States. Participation was voluntary and participants could engage in one or more sessions, depending on their needs and/or goals. Incentives for participation in worksite wellness varied per company, of which all visits required no out-of-pocket expenses or monetary compensation for the employee.
Each visit documented was an individual face-to-face interaction between an employee and a Registered Dietitian Nutritionist (RDN). RDN’s have been trained on basic motivational interviewing and counseling skills which were used during each employee session. Nutrition coaching and Medical Nutrition Therapy was based on personalized instruction, involving participants’ health goals and associated nutrition and lifestyle activity. Each participant received a counseling session ranging from 15–60 minutes, depending on the needs of the participant. Data were collected from March to December 2017. Analyses were conducted in 2018.
Measures
Participation in worksite wellness was defined as participating in at least one counseling session with an RDN at the work location. For each session, the RDN recorded assessment and treatment notes via an internal medical charting software. No details on individual nutrition assessment were provided to the researcher team nor analyzed in this study.
Data collected from each employee at each visit included: Self-reported anthropometrics (height, weight, calculated BMI) RDN measured anthropometrics (systolic blood pressure, diastolic blood pressure, waist circumference, neck circumference) Self-reported dietary intake (daily servings of whole grains, vegetables, fruit, dairy, fish and water) Self-reported physical activity measures Nutrition, physical activity and social goals (set between RDN and employee and monitored progress at each session)
This study was deemed exempt by the Texas A&M University Institutional Review Board. This study was deemed exempt under federal regulation 45 46.101 (IRB2016–0674).
Statistical analysis
SPSS syntax was created to create two databases, one for level-1 (appointment-level) data and one for level-2 (patient-level) data. Level-1 data contained 2,180 appointments with patient ID numbers repeated for each appointment reported by that particular patient (i.e., each patient will have multiple rows of data). Level-2 data included only one entry per patient and contained 1,123 patients. This type of multilevel data analysis allows for analysis of variance across levels of data, controlling for the variances explained by level-2 group membership. Significant relationships were identified if p < 0.05. Descriptive statistics were are presented in Table 1. Two separate HLM models were conducted; one with weight as the dependent variable and one with systolic blood pressure as the dependent variable.
Descriptive statistics
Descriptive statistics
Note = aIncludes data from patients who only had one appointment, bincludes all appointments from all patients.
Separate predictive equations were created to account for the multiple levels. The outcome variable is identified as Y in models with linear outcomes [24]. The level-1 equation was:
Y =β0 +β11X1 +β2X2 + R
Where Y = the dependent variable, β0 is the constant (i.e., intercept), β1 is the regression coefficient of X1 (i.e., whole grain intake), β2 is the effect of X2 (i.e., physical activity intensity), and R is error. In multilevel analysis, each X becomes an outcome for level-2 equations. The predicted level-2 equations were therefore:
β00 =
γ
00 +
γ
01W1 +
γ
02W2 +
γ
03W3 +
γ
04W4 + u0
β10 =
γ
10 +
γ
11W1 +
γ
12W2 +
γ
13W3 +
γ
14W4 + u1
β20 =
γ
20 +
γ
21W1 +
γ
22W2 +
γ
23W3 +
γ
24W4 + u2
where γ00 is the overall mean intercept (i.e., intercept of the intercepts), γ01 is the regression coefficient of W1 (i.e., gender) relative to its intercept, γ02 is the regression coefficient of W2 (i.e., body type) relative to its intercept, γ03 is the regression coefficient of W3 (i.e., number of visits) relative to its intercept, γ04 is the regression coefficient of W4 (i.e., age) relative to its intercept, γ10 is overall mean of β1 adjusted for all W, γ20 is overall mean of β2 adjusted for all W, γ11 is the regression coefficient for the effect of W1 on β1, γ12 is the regression coefficient for the effect of W2 on β1, γ13 is the regression coefficient for the effect of W3 on β1, γ14 is the regression coefficient for the effect of W4 on β1, γ21 is the regression coefficient for the effect of W1 on β2, γ22 is the regression coefficient for the effect of W2 on β2, γ23 is the regression coefficient for the effect of W2 on β3, γ24 is the regression coefficient for the effect of W4 on β3, u0 is the random effects on the intercept, u1 is the random effects on the slope of β1, and u2 is the random effects on the slope of β2. This model will test both direct and moderating effects while controlling for all variables in the model. The hypothesized models are shown in Fig. 1

This figure shows the hypothesized model being tested, including all 28 individual hypotheses being tested.
The first models analyzed were the null models for both dependent variables. The null models indicated that approximately 98.7%of the variance in weight was at the patient-level (rather than at the appointment-level) and approximately 84.0%of the variance in systolic blood pressure was at the patient-level. The results of the full HLM modeling for weight and systolic blood pressure are presented in Tables 2 3 respectively.
Results of the HLM modeling for weight
Results of the HLM modeling for weight
Note: # = p≤0.10, * = p≤0.05, ** = p≤0.01, *** = p≤0.0
Results of the HLM modeling for systolic blood pressure
Note: # = p≤0.10, * = p≤0.05, ** = p≤0.01, *** = p≤0.001.
The HLM model presented in Table 2 indicates that patient gender (t-ratio = –2.64, p = 0.008) and patient body type (t-ratio = –4.50, p < 0.001) have statistically significant direct effects on weight. Females, on average, were 22.08 pounds less than males. Also, patients with a pear body shape were, on average, 26.36 pounds lighter than patients with an apple body shape independent of gender. This HLM model also identified two statistically significant cross-level interaction (moderating) effects. The first such effect was gender’s moderation (t-ratio = –2.16, p = 0.03) of whole grain servings’ effect on weight. The second such effect was number of visit’s moderation (t-ratio = 2.41, p = 0.02) of whole grain servings’ effect on weight.
The HLM model presented in Table 3 indicates that patient age (t-ratio = 1.98, p = 0.05) has a statistically significant direct effect on systolic blood pressure. For every additional year in age, systolic blood pressures increase.468 units on average. This HLM model also identified two statistically significant cross-level interaction (moderating) effects. The first such effect was body type moderation (t-ratio = 2.88, p = 0.004) of whole grain servings’ effect on systolic blood pressure. The second such effect was number of visit’s moderation (t-ratio = –2.11, p = 0.04) of whole grain servings’ effect on systolic blood pressure.
These results demonstrate the current need for nutrition intervention within worksite wellness, as many employees have room for improvement in lifestyle choices for optimal health. These data indicate that regardless of nutrition counseling, there are improvements and regressions in diet and lifestyle behaviors. Moreover, these impacts were seen at multiple worksite wellness programs, across multiple companies, across multiple states. Positively, it was seen that as clients increased the number of visits with an RDN, their whole grain servings improved and associated systolic blood pressure. These findings support the national recommendation from the Dietary Guidelines for Americans 2015–2020 to increase whole grain intake as part of a healthy eating pattern [25]. Moreover, there was slight improvement in the consumption of daily fruits and vegetables and weekly physical activity, all important characteristics of a healthy lifestyle.
The research has shown that implementing a worksite wellness program and utilizing behavior change counseling, such as motivational interviewing, can be key to promote behavior change and reducing risk of chronic disease [26, 27]. While no largely significant differences were observed in this study, there were slight improvements in some dietary and lifestyle behaviors. Other single-site programs have shown similar results in improvements of nutrition and lifestyle behaviors, but no significant changes in associated weight [15, 28–30]. This suggests that there are barriers and challenges with nutrition counseling in the workplace. Long-term behavior change in lifestyle habits requires more frequent engagement with RDNs to monitor progress and encourage further behavior change. If diet and lifestyle are at the root of this obesity epidemic, then integration of a more personalized RDN-led worksite wellness program may be the first step into prevention and management of chronic disease. There is sufficient evidence to support that an improvement in dietary and lifestyle behaviors has profound benefits on work productivity and healthcare costs to our systems [6, 7].
Strengths and limitations
This study had several areas of strengths. This is a large data set from companies across the United States, providing generalizability to the results in the worksite setting. This study is one of the first of its kind to document the impact of multiple site, RDN-led worksite wellness in its relationship to behavior change. There are several study limitations that need to be addressed. First, structured sessions with specific outcomes was not a focus during these counseling sessions, rather it was personalized nutrition and lifestyle counseling. As this may result in individual benefits, it is difficult to quantify the group benefits because each person may seek different behavior changes. Employees who participated in this program were self-selected and have a similar profile (female, Caucasian), thus limiting the generalizability of the results to diverse, multicultural populations. Engagement in more than one session was optional by the employees, suggesting there may be some participation bias due to motivation. Lastly, the measures that were used in this study were self-reported data and thus may not accurately reflect true dietary and lifestyle behaviors.
Future research needs to measure individual impacts and disease-specific impacts of RDN-led medical nutrition therapy in the workplace setting, rather than grouping all participants together. In addition, measuring corresponding behavior change impacts on medical care costs and medical claims per individual. These future studies may yield additional information on how worksite wellness programs can be improved and implemented within more companies.
Conflict of interest
KH: Previous employment with Family Food LLC as a corporate wellness RDN. Family Food LLC has paid this author to run statistical analyses on individual company data and provided funding to present research results at conferences. MF: Employment with Nutrimedy, which provides RDN-led technology-based corporate wellness to employers. Nutrimedy has not contributed any money to this study.
Informed consent
This study was deemed exempt by the Texas A&M University Institutional Review Board. This study was deemed exempt under federal regulation 45 46.101 (IRB2016-0674).
