Obesity Reduction Black Intervention Trial (ORBIT): design and baseline characteristics

Abstract

Background: Obesity is associated with many chronic diseases, and weight loss can reduce the risk of developing these diseases. Obesity is highly prevalent among Black women, but weight loss treatment for black women has been understudied until recently. The Obesity Reduction black Intervention Trial (ORBIT) is a randomized controlled trial designed to assess the efficacy of a culturally proficient weight loss and weight loss maintenance program for black women. This paper describes the design of the trial, the intervention, and baseline characteristics of the participants.

Methods: Two hundred thirteen obese black women aged 30-65 years were randomized to the intervention group or a general health control group. The intervention consists of a 6-month weight loss program followed by a 1-year maintenance program. Weight, dietary intake, and energy expenditure are measured at baseline, 6 months, and 18 months.

Results: More than 40% of participants had a baseline body mass index (BMI) >40 kg/m(2) (class III obesity). Intake of fat and saturated fat was higher and consumption of fruit, vegetables, and fiber was lower than currently recommended guidelines. Self-reported moderate to vigorous physical activity was high (median 85 min/day). However, objectively measured physical activity among a subgroup of participants was lower (median 15 min/day).

Conclusions: Weight loss among obese black women has received inadequate attention in relation to the magnitude of the problem. Factors that contribute to successful weight loss and more importantly, weight loss maintenance need to be identified.

FIG. 1.

Study design of the ORBIT project and participant flow through randomization.

FIG. 2.

Figure Rating Scale showing nine silhouettes of women displayed in order from underweight to obese. (Reprinted with permission from reference .)