Obesity: Worksite Programs

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Findings and Recommendations

The Community Preventive Services Task Force (CPSTF) recommends worksite programs intended to improve diet and/or physical activity behaviors based on strong evidence of their effectiveness for reducing weight among employees.

The full CPSTF Finding and Rationale Statement and supporting documents for Obesity Prevention and Control: Worksite Programs are available in The Community Guide Collection on CDC Stacks.

Intervention

Worksite nutrition and physical activity programs are designed to improve health-related behaviors and health outcomes. These programs can include one or more approaches to support behavioral change including informational and educational, behavioral and social, and policy and environmental strategies.

About The Systematic Review

The CPSTF finding is based on evidence from a systematic review of 47 studies (search period 1966 — 2005). The review was conducted on behalf of the CPSTF by a team of specialists in systematic review methods, and in research, practice, and policy related to obesity prevention and control.

Study Characteristics

  • Half the studies were conducted in the U.S.; remaining studies were conducted in Europe, Australia, New Zealand, Japan, Canada, India, and Iceland
  • The purpose of the interventions, as stated by study authors, included CVD risk reduction (34%); weight control (26%); and physical fitness (19%)
  • The behavioral focus of each intervention included diet and physical activity behaviors (57%); diet only (21%); and physical activity only (21%)
  • In 25 studies, the majority of participants (80%) held white-collar jobs; in four studies, participants held blue-collar jobs; in 19 studies, this could not be determined
  • Among studies that reported sex of participants, most included both men and women (64%)
  • Among 46 of the 47 included studies, the median sample size was 141 (range 29 3728). The final study, a WHO multicounty trial, had a sample size of 63,732
  • Of the 39 studies reporting attrition, the median attrition rate was 17% (range: 0% 82%)

Summary of Results

Forty-seven studies qualified for the review and included three outcome measures: body mass index (BMI), weight, and percent body fat.

  • The most common intervention strategies included both informational and behavioral skills components (32 studies). Few studies (4 studies) looked at policy and environmental changes in the worksite
  • Effects on the three outcomes consistently favored:
    • The intervention group compared to the controls (31 studies)
    • Those receiving more intensive versus less intensive strategies (9 studies)
    • In individually randomized controlled trials, results showed that compared with control groups after 12 months, participating employees lost an average of 2.8 pounds (9 studies) and reduced their average BMI by 0.5 (6 studies)
  • No one focus, diet or physical activity, or combination of both appeared to be better than others in terms of its effect on weight loss

Summary of Economic Evidence

  • The range of cost-effectiveness estimates from three studies varies from $1.44 to $4.16 per pound of loss in body weight (reported in 2005 dollars)
  • One study conducted a cost-effectiveness analysis of a worksite weight-loss program consisting of three competitions
    • Intervention costs for the three competitions were $6149, $1377, and $762, respectively
    • The cost per pound of weight lost in these three competitions was $4.16 for a 12-week program, $2.19 for a 13-week program, and $1.60 for a 15-week program
  • One study analyzed the cost effectiveness of team competitions and estimated a cost of $1.45 to lose 1% of body weight
  • One study assessed the cost effectiveness of a 3-month worksite weight-loss program
    • The campaign cost was $25,376 and the study reported a cost of $1.77 per pound of weight lost
  • One study reported costs for a self-help weight loss awareness campaign
    • The intervention cost was $2634 excluding volunteer time and $3966 including volunteer time
    • Cost-effectiveness ratios were $2.17 and $1.44, respectively, per pound of weight lost
  • One study reported a reduction in disability and major medical costs of $1022.96 per participant at a worksite physical fitness program for a 1-year period
    • The intervention costs of $75,750 included operating expenses, laboratory tests, physical examinations, and capital investment
    • The intervention returned $1.59 for every dollar invested in the program resulting in a net saving of $0.59 per $1.00

Applicability

Based on the data available, the results of this review may be generalized to a white-collar workforce where both overweight and other chronic disease risk conditions exist.

Evidence Gaps

Although we found evidence that worksite programs targeting nutrition and physical behaviors confer modest, positive, weight-related benefits, important research questions remain.

    • One of our initial review questions was only partially answered: Which employee populations benefit the most from worksite health promotion interventions targeted at weight? Weight status varies considerably among employee populations. Reporting individual weight measure for employees from baseline to follow-up is not feasible in large occupational health studies. Instead, measurement of weight change in the studies we reviewed was usually presented as group mean change in BMI, pounds, kilograms, or percent body fat. Thus, we could not determine if those at greatest risk (i.e., overweight or obese) benefited more or less. Nor could we determine if a few employees lost a large amount of weight or if many employees lost small amounts.
    • In addition to measuring mean weight change, it would also be useful to learn what percent of participants had clinically meaningful weight loss (i.e., >5% or >10 % body weight loss).
    • Reporting changes in the prevalence of overweight and obesity in the employee population as a result of the intervention would provide information about intervention effects at the population-level. Highly effective interventions that reach only a small percent of the population will likely not affect the prevalence.
    • Forty percent the studies lacked information to determine differential effects according to blue or white collar job status. Those that did report occupational status included predominantly white collar workers. Race and ethnicity data were also limited.
    • A variety of worksite settings were represented in this review, which lends to the generalizability of the findings. Information on the feasibility of implementing programs across small to very large worksite settings, however, was hampered by missing workplace size data in 64% of the studies.
    • We found no association between program effectiveness and focus of the program (e.g., CVD risk reduction, weight loss, physical fitness) or behavioral focus (diet or physical activity). Because the majority of programs used behavioral plus informational strategies, it was difficult to contrast program components with respect to effectiveness.
    • Questions remain about the effect on employee weight status when implementation of environmental change (e.g., providing easy access to affordable, healthy foods, or modifying the physical environment to encourage physical activity) and employer policy strategies (health insurance incentives, contribution to gym membership fees, etc.) is included.
    • One third of the RCTs provided insufficient statistical information to allow meta-analytic pooling of effects. Only a few reported intention to treat analysis. Reporting on intervention intensity, duration, and fidelity was often ambiguous. Future studies will contribute more to the empirical knowledge base if they follow the CONSORT guidelines for reporting RCTs and TREND guidelines for reporting non-randomized studies.

Implementation Considerations and Resources

  • When one or more intensive modes of intervention were provided to participants there appeared to be an increase in program impact. For example, offering structured programs (i.e., scheduled sessions) appears more effective than unstructured approaches, and information plus behavioral counseling confers more benefit than providing information alone
  • There was no apparent difference in program effectiveness based on lay versus professional group leaders
  • Obesity prevention programs at worksites may enhance employee self-confidence and improve the relationship between management and labor, and boost profits by increasing employee productivity and reducing medical care and disability costs

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