Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2012 Jan;54(1):50-4.
doi: 10.1016/j.ypmed.2011.10.018. Epub 2011 Nov 3.

Physical activity and dietary behavior change in Internet-based weight loss interventions: comparing two multiple-behavior change indices

Jordan A Carlson  1 , James F Sallis, Ernesto R Ramirez, Kevin Patrick, Gregory J Norman
Affiliations
Randomized Controlled Trial

Physical activity and dietary behavior change in Internet-based weight loss interventions: comparing two multiple-behavior change indices

Jordan A Carlson et al. Prev Med. 2012 Jan.

Abstract

Objective: To investigate the effects of two Internet-based weight loss interventions on physical activity (PA) and dietary behaviors using two approaches for computing combined behavior change.

Method: Participants were 352 overweight/obese women and men completing 12-month interventions in San Diego, California during 2002-2007. Moderate-to-vigorous PA (MVPA) and sedentary time were measured with accelerometers, and dietary fat and fruit and vegetable intake were assessed with food frequency questionnaires. Longitudinal analyses tested the effect of the intervention on combined health behavior change quantified using a standardized residualized change index (SRCI) and a risk factor change index (RFCI).

Results: At baseline, participants engaged in an average of 153 min/week of MVPA and 525 min/day of sedentary time, and consumed 37% of calories from fat and <3 fruits and vegetables per day. The interventions had a significant effect on combined behavior change as measured with each approach (p<0.001). The intervention effect was larger (p<0.001) when evaluated using the SRCI (standardized regression coefficient [Beta]=0.30) than the RFCI (β=-0.18).

Conclusion: Interventions that target both PA and dietary behaviors appear effective. The SRCI was more sensitive for evaluating the intervention, but the RFCI may be easier to use for communicating public health significance.

PubMed Disclaimer

References

    1. Bandura A. Social cognitive theory. In: Vasta R, editor. Six Theories of Child Development. Greenwich, CT: JAI; 1989.
    1. Calfas KJ, Patrick K, Hagler A, Norman GJ, Zabinski MF, Sallis JF. Twelve-month dietary and physical activity outcomes in ‘PACEi-Women in Balance’: A primary-care and web-based intervention. Ann.Behav.Med. 2006;31:184.
    1. Centers for Disease Control and Prevention (CDC) Healthy People 2010: Heart Disease and Stroke. 2005.
    1. Clogg CC, Petkova E, Haritou A. Statistical methods for comparing regression coefficients between models. Amer. J. Sociol. 1995;100:1261–1293.
    1. Freedson PS, Melanson E, Sirard J. Calibration of the computer science and applications, Inc. accelerometer. Medicine & Science in Sports & Exercise. 1998;30:777–781. - PubMed

Publication types