Introduction to the special issue on achieving healthy weight in black American communities.

The prevalence of obesity is high in the United States, and highest among racial and ethnic minority groups. This special issue of Obesity Reviews is based upon evidence reviews prepared for and presented at a national invited workshop convened by the African American Collaborative Obesity Research Network (AACORN) in August of 2012. A set of potential topics was developed, a priori, and AACORN network members and colleagues with relevant expertise were invited to lead evidence reviews. The result is 10 articles focused on providing a comprehensive picture of what is known and unknown about interventions to prevent and treat obesity or improve weight-related behaviours in African American adults and children. Evidence reviews included in this special issue focus on children and adolescents (n=2); adults from various perspectives (n=5); eHealth interventions (n=1); interventions within faith organizations (n=1); and environmental and policy change interventions (n=1). Overall, the reviews show a small evidence base for research on African Americans and call for additional prioritization of funding to include studies that can inform action and bring progress in obesity prevention and treatment in African Americans on par with the scope and seriousness of the problem.

What works for obesity prevention and treatment in black Americans? Research directions.

Obesity prevalence in black/African American children and adults of both sexes is high overall and compared with US whites. What we know, and do not know, about how to enhance the effectiveness of obesity prevention and treatment interventions in African Americans is the focus of the 10 articles in this special issue of Obesity Reviews. The evidence base is limited in quantity and quality and insufficient to provide clear guidance. With respect to children, there is relatively consistent, but not definitive support for prioritizing the systematic implementation and evaluation of child-focused interventions in pre-school and school settings and outside of school time. For adults or all ages, developing and refining e-health approaches and faith-based or other culturally and contextually relevant approaches, including translation of the Diabetes Prevention Program intervention to community settings is indicated. Major evidence gaps were identified with respect to interventions with black men and boys, ways to increase participation and retention of black adults in lifestyle behaviour change programmes, and studies of the impact of environmental and policy changes on eating and physical activity in black communities. Bold steps related to research funding priorities, research infrastructure and methodological guidelines are recommended to improve the quantity and quality of research in this domain.

Effectiveness of pre-school- and school-based interventions to impact weight-related behaviours in African American children and youth: a literature review.

This review assessed the effectiveness of pre-school- and school-based obesity prevention and/or treatment interventions targeting healthy eating, physical activity or obesity in African American children and adolescents. Systematic searches were conducted for English-printed research articles published between January 1980 and March 2013. Retained articles included experimental studies conducted in the United States that targeted ≥ 80% African American/black children and adolescents and/or studies whose results were stratified by race/ethnicity, and that were conducted in pre-schools/head start or schools (excluding after-school programmes). Of the 12,270 articles identified, 17 met the inclusion criteria (pre-school, n=2; elementary school, n=7; middle and secondary schools, n=8). Thirteen studies found significant improvements in nutrition (pre-school, n=1; elementary, n=7; secondary, n=5) and three found significant improvements in physical activity (pre-school, n=1; elementary, n=2) variables of interest. Two studies (pre-school, n=1; secondary, n=1) reported significant reductions in obesity in African American children. The evidence available suggests school-based interventions are effective in promoting healthy nutrition behaviours in African American children. Conclusions overall and, particularly, about effects on physical activity and obesity are limited due to the small number of studies, differences in assessment approaches and a lack of follow-up assessments.

Examining the evidence for policy and environmental strategies to prevent childhood obesity in black communities: new directions and next steps.

Exposure to physical and policy environments that limit availability, affordability and appeal of healthy eating and active living options is higher for U.S. blacks than whites. This may contribute to high risk of obesity in black communities and limit effectiveness of preventive interventions. Here, we assess applicability to black Americans of findings from a prior evidence review system designed to accelerate the discovery and application of policy and environmental strategies for childhood obesity prevention and assess external validity. The database included 600 peer-reviewed articles reporting data from 396 sets of studies (study groupings) published from January 2000 through May 2009 and pertained to 24 types of policy and environmental strategies. Only 33 study groupings (~8%) included ≥ 50% black Americans or reported subgroup analyses. Of 10 evaluation studies for interventions rated as effective for all populations in the primary review, 8 suggested effectiveness of child-focused interventions in school or child care settings for obesity- or physical activity-related outcomes in black Americans. Overall findings highlight the need for rigorous evaluations of interventions that reach black children in community or institutional settings, and conceptual frameworks and research designs geared to identifying ethnic or ethnicity-income group differences in intervention effects.

A systematic review of physical activity interventions among African American adults: evidence from 2009 to 2013.

This review extends findings from four previous reviews of physical activity (PA) interventions among African Americans (AA) and includes papers published between January 2009 and August 2013. Eligible papers were retrieved using strategies employed in previous reviews. Overall, 16 relevant papers were identified, including four pilot studies and 12 full trials. Interventions were based on a variety of behavioural sciences theories. The most common setting for interventions was churches. Most interventions lasted >6 months; few interventions included >6 months of post-intervention follow-up. Overall, studies identified within-group differences showing positive improvements in PA, and most studies showed statistically significant between-group differences in at least one measure of PA. A quality score was used to rate various elements of the studies and provide a numerical assessment of each paper; scores ranged from 3 to 10 out of 13 possible points. The current review indicates a continued need for studies that use objective PA measures, assess long-term intervention impact, provide specific PA goals for interventions, include more attention to strategies that can increase retention and adherence among AA study participants, include AA men and determine the independent and synergistic effects of individual and environmental (socio-cultural and built) change strategies.

BMI-referenced cut points for pedometer-determined steps per day in adults.

BACKGROUND: The goal of this study was to establish preliminary criterion-referenced cut points for adult pedometer-determined physical activity (PA) related to weight status defined by body mass index (BMI). METHODS: Researchers contributed directly measured BMI and pedometer data that had been collected (1) using a Yamax-manufactured pedometer, (2) for a minimum of 3 days, (3) on ostensibly healthy adults. The contrasting groups method was used to identify age- and gender-specific cut points for steps/d related to BMI cut points for normal weight and overweight/obesity (defined as BMI <25 and >or=25 kg/m2, respectively). RESULTS: Data included 3127 individuals age 18 to 94 years (976 men, age = 46.8 +/- 15.4 years, BMI = 27.3 +/- 4.9; 2151 women, age = 47.4 +/- 14.9 years, BMI = 27.6 +/- 6.4; all gender differences NS). Best estimated cut points for normal versus overweight/obesity ranged from 11,000 to 12,000 steps/d for men and 8000 to 12,000 steps/d for women (consistently higher for younger age groups). CONCLUSIONS: These steps/d cut points can be used to identify individuals at risk, or the proportion of adults achieving or falling short of set cut points can be reported and compared between populations. Cut points can also be used to set intervention goals, and they can be referred to when evaluating program impact, as well as environmental and policy changes.