Among 1,958 HealthStyles respondents who had lost weight or tried to lose weight, almost one-third had been succeeded in losing weight and keeping it off. Overall, successful weight losers and maintainers were more likely to engage in physical activity for at least 30 minutes per day, or to add physical activity to their daily routine than those unsuccessful at weight loss and maintenance. Finding suggests that individuals who were successful at weight loss and maintenance had higher odds of taking part in physical activity on most days of the week than those who were unsuccessful at weight loss. Interestingly, individuals who were successful at weight loss and maintenance had lower odds of using over-the-counter diet products than those who were unsuccessful at weight loss. Similarly, self-monitoring behaviors such as weighing oneself daily were also reported more often by successful weight losers than unsuccessful weight losers. There is earlier evidence that people who weigh themselves at least weekly are more likely to lose weight and avoid regaining it than those who weigh themselves inconsistently [12
]. In addition, self-monitoring of body weight was found to be an important factor among members of the National Weight Control Registry, a group of successful weight losers [8
]. In a comprehensive review by Teixeira and colleagues (2005), a self-motivated cognitive style was found to predictor compliance to a multitude of behaviors necessary for successful weight management [14
Questions on a wide range of weight-control strategies (e.g., counting calories, reducing amount of food, eating fewer fatty foods, consuming reduced-fat products) revealed no differences by success at losing weight, but these questions referred to having tried something in the past 12 months. When the focus was weight-control practices that were followed most days of the week, the results were significantly different, as planning meals, tracking calories, tracking fat, and measuring food were all more common in successful weight losers than unsuccessful weight losers. Others have found similar results [8
]. Gorin and colleagues [15
] found that consistency in dieting through the week and year was better for maintaining weight loss than simply restricting dieting to weekdays. Although it makes intuitive sense (and is consistent with our study) that tracking one's behavior may lead to better health practices, with the exception of food diaries, there is a lack of research to support this hypothesis.
Although not a specific physical activity recommendation for weight loss, weight training may, through various mechanisms increase the overall expenditure of energy, and thereby aid in weight control [16
]. Much more needs to be known about how weight training may aid in weight maintenance, as it has been reported by 20% of members of the National Weight Control Registry [9
]. In our study, weight lifting was almost twice as common among successful weight losers, and we also found that men were more likely than women to be successful at losing weight. One might conclude that a greater predilection for weight lifting was part of the reason for the men's greater success in losing weight, or perhaps, weight lifting was for many participants a way of training for specific sports and thus, possibly a marker for a physically active lifestyle.
The odds of being a successful weight loser were lower for those who reported being influenced by dietary weight control barriers (e.g., eat away from home too often, diet/health foods not satisfying, diet/health food costs too much) compared to those who reported little to no influence of dietary barriers on weight control. This suggests that issues of taste, cost and convenience may need to be included in initiatives aimed at helping individuals lose or maintain weight. Our finding that cooking or baking for fun was more common among those successful at weight loss was by no means unexpected but perhaps not as predictable. Perhaps those who enjoy cooking and baking have meals at home more often; meals that one would expect to be healthier than those in fast-food or full-service restaurants. The nutritional quality of food prepared at home has been found to be superior to foods prepared away from home, with the latter being higher in total calories, fat, and sodium and lower in fiber [19
It was also not surprising that barriers to exercise (including being too tired, having no time or no one with whom to exercise, finding it too hard to maintain an exercise routine) were associated with being unsuccessful at losing weight. Thus, both time pressure and lack of social support seem important. Elfhag and Rossner (2005) found that social support, better coping strategies and the ability to handle life stress were factors associated with successful weight maintenance [10
]. The Task Force on Community Preventive Services [20
] suggests that environmental barriers and lack of social support influence exercise behavior. Increasing convenient opportunities to engage in lifestyle physical activity (e.g., making small changes to the built environment, such as sidewalks, parks, and trails) may motivate some sedentary people to change their behavior.
The findings of this analysis are subject to several limitations. First, data from the HealthStyles survey are cross-sectional, and thus causality cannot be determined. Second, participants are not randomly drawn from the US population, but results of the HealthStyles survey have been shown to be comparable to those obtained through the Behavioral Risk Factor Surveillance System (BRFSS), which does use a probability sampling technique [21
]. Specifically, nine items on the HealthStyles survey were comparable to items on the BRFSS survey from 1995 to 2001, yielding 34 same-year data pairs where the two surveys could be compared directly [21
]. The average difference for the 34 pairs of percentages was 2.4 percentage points, and the correlation between the 34 pairs was r = 0.99 [22
]. A third concern is that our primary survey questions have not been tested for validity or reliability. Fourth, the questionnaire did not include questions as to how much weight was lost, which limits the definition of a successful weight loss maintainer. While there is no consensus in the literature about how to define weight maintenance, it is important to consider defining long-term maintenance in terms of the amount of weight change and time frame of the occurrence [23
]. Finally, the questionnaire provided limited details about the intensity or duration of most of the physical activities/sports, and it lacked an objective measure of how much weight was lost and kept off. The strengths of this study include the fact that it was drawn from a sample of American households and that the survey questions allowed for the categorization of an assortment of dietary variables, leisure-time activities, and physical activities or sports that might be associated with successful and unsuccessful weight loss.