Agenda and Abstracts
Predictors of Obesity: Weight Gain, Diet, and Physical Activity
The National Weight Control Registry
Rena R. Wing, Ph.D.
The Miriam Hospital/ Brown Medical School
Whereas other presentations will focus on weight change in the general population, this presentation focuses on characteristics of those who have successfully lost weight and the factors associated with their subsequent weight regain. Data are derived from the National Weight Control Registry, which was founded in 1994 by Drs. James Hill and Rena Wing, and now includes over 5000 individuals who have lost greater than or equal to 30 lbs and kept it off greater than or equal to 1-year. Members are recruited across the US and Canada by newspapers and magazine articles, and asked to complete questionnaires about the weight loss and maintenance process.
The demographic characteristics of registry members are as follows: 80% women, 82% college educated, 95% Caucasian, 64% married, average age = 46.8 years. About half report being overweight as a child and almost 75% have one or two obese parents.
Participants self-report their current weight and their maximum weight, and provide names of physicians or weight loss counselors who can verify the information. In a subgroup where these sources were contacted, the self-report information was found to be extremely accurate. Registry members have lost an average of 33 kg and maintained their weight loss for 5.7 years; 13% have maintained their weight loss for > 10 years. BMI was reduced from 36.7 to 25.4 kg/m2.
This presentation will provide information about the self-reported behaviors of these successful weight losers at the time they enter the registry and discuss characteristics that relate to weight change over 1-2 years of follow-up in the registry.
Registry members report having used a variety of strategies to lose their weight; approximately half report that they received some type of help with weight loss (commercial program; physician) and the other half report losing weight on their own. The vast majority (89%) used a combination of diet and exercise to produce weight loss.
Upon entering into the registry, participants complete the Block Food Frequency, Paffenbarger Activity, and the Three Factor Dietary Restraint questionnaire. Based on these questionnaires, registry members report eating a low calorie, low fat diet. In addition, we find that 78% consume breakfast every day. Another characteristic of registry members is their high level of physical activity (2800 kcal/week). Registry members also report frequent monitoring of body weight and score high on dietary restraint (mean = 7.1).
Recently we have begun to examine variables associated with weight regain in the registry. When followed over 1-year, 35% of the members gained >= 5 lb (7 kg on average), 59% maintained their weight, and 6% lost >= 5 lb. We have identified demographic, behavioral and psychological factors associated with weight regain:
- The strongest predictor of weight regain is the number of years the participant has successfully maintained their weight loss.
- Persons with a medical trigger are more likely to maintain their weight loss over time compared to those with no trigger or a non-medical trigger.
- Persons with lower scores on dietary disinhibition (< 6 on the Eating Inventory) were 60% more likely to maintain their weight over the following year.
- Persons with lower scores on the Beck Depression Inventory were more likely to maintain their weight loss.
- Individuals who regained their weight increased their fat intake, while maintainers kept theirs constant.
- Regainers reported greater decreases (- 800 kcal/week) in activity from baseline to 1-year than maintainers (- 400 kcal/week)
- Regainers reported decreases in dietary restraint and increases in disinhibition.
- Persons who reported eating a consistent diet across the week and year (i.e. were equally strict on weekdays and weekends and on holidays vs non holidays) were 1.5 times less likely to regain greater than or equal to 5 lb compared to those who reported more flexibility.
- Recover from small relapses was rare. After a participant experienced a small regain (even 1-2 kg), they typically went on to gain more weight.
- Gorin, A.A., Phelan, S., Hill, J.O., and Wing, R.R., Promoting long-term weight control: Does dieting consistency matter? International Journal of Obesity and Related Metabolic Disorders, 2004. 28(2): p. 278-281.
- Gorin, A., Phelan, S., Hill, J.O., and Wing, R.R., Medical triggers are associated with better long-term weight maintenance. Preventive Medicine, in press.
- Klem, M.L., Wing, R.R., McGuire, M.T., Seagle, H.M., and Hill, J.O., A descriptive study of individuals successful at long-term maintenance of substantial weight loss. American Journal of Clinical Nutrition, 1997. 66: p. 239-246.
- McGuire, M.T., Wing, R.R., Klem, M.L., Lang, W., and Hill, J.O., What predicts weight regain in a group of successful weight losers? Journal of Consulting and Clinical Psychology, 1999. 67(2): p. 177-185.
- Phelan, S., Hill, J.O., Lang, W., Dibello, J.R., and Wing, R.R., Recovery from relapse among successful weight maintainers. American Journal of Clinical Nutrition, 2003. 78: p. 1079-1084.
- Wing, R.R. and Hill, J.O., Successful weight loss maintenance. Annual Review in Nutrition, 2001. 21: p. 323-341.