Abstract
Despite the availability of the US Dietary Guidelines for Americans, the prevalence of obesity in adults has increased by 200% since 1980. Although few people have lost weight and maintained weight loss long term, some have and are tracked by the National Weight Control Registry. Results from these studies suggest that people attempting to maintain weight loss should (a) eat a low-calorie diet, (b) eat a routine diet, (c) self-monitor food intake and weight, and (d) engage in physical activity.
Dietary guidelines have been available to Americans since 1980. 1 Many improvements have been made to these initial guidelines, and a greater empirical basis has been provided for the selection of recommendations. Despite the improvements in the science behind the recommendations, the implementation by Americans appears to be lacking more than ever. Since the publishing of these recommendations in 1980, the prevalence of obesity and severe obesity in US adults has increased by more than 200% and 400%, respectively. 2 This is concerning because obesity is highly associated with developing diabetes and other chronic diseases, which are also becoming more prevalent, and efforts toward weight loss are typically not maintained long term.3,4
One potential pitfall that patients experience with the Dietary Guidelines is their inability to follow the numerous recommendations. To our knowledge, no study has examined the feasibility of following all of the current recommendations, but it is our assumption that following all of the guidelines is probably not realistic for most people. However, most people can take steps that are closer in line with guidelines. Behaviorally, this process is called shaping.5,6 Shaping requires one to set a series of short-term goals and to provide consecutive rewards when the goals are met. As time goes on, the patient more closely approximates the desired level of change. Because the desired outcome may be reached before the larger goal is met, attaining the larger goal may not be of ultimate importance. For example, a patient may be trying to lower her blood pressure through physical activity. She may find a substantial lowering of blood pressure after incorporating 30 minutes of moderate to vigorous physical activity instead of the recommended amount of (60 minutes). In this example, 30 minutes of physical activity may be sufficient for this individual.
Despite the improvements in the science behind the recommendations, the implementation by Americans appears to be lacking more than ever.”
An approach that incorporates shaping is typically not used by health care providers. Patients are often told the correct amount of physical activity, calories, or other factors that are associated with weight loss with the assumption that they will ultimately meet these large goals. To make matters worse, many patients feel that they must attain the recommended levels of change to be successful. These goals are often very difficult to reach and to maintain for a majority of patients. For these reasons alone, it is easy to understand why patients can quickly become frustrated. The need for individualization of recommendations is extremely important. Even in some of the earliest forms of the Dietary Guidelines, there was a recognition that a wide variation in individual differences exists and that not all recommendations would work for everyone. 7 However, it is difficult to know which behaviors may play a more important role in weight loss and maintenance. There is clearly a great need to bridge the divide between research and practice in order to identify strategies that are effective.
One way to begin to bridge this gap is to examine what has worked and is working for people who are successful at making and maintaining substantial weight loss. The National Weight Control Registry has been tracking Americans who have lost at least 30 pounds or more and maintained that loss for at least 1 year since 1995. Currently, data have been collected on more than 4000 participants. 8 Based on the results from these data, commonalities among the strategies used by those successful at maintaining weight loss have been identified. These strategies include eating a low-calorie, low-fat diet, eating a routine diet, self-monitoring of food intake and weight, and engaging in physical activity.
Diet and Eating Routines
Although there was variability in diet reported by registry members, people who were successful in maintaining weight loss reported eating a low-calorie, low-fat diet consisting of fewer than 1400 calories a day and less than 24% of calories from fat. 9 A 1400-calorie diet is well below what is typically recommended for adults in the US Dietary Guidelines. 10 To maintain this low-calorie, low-fat diet, participants have reported that they engage in a number of routine behaviors such as eating a consistent diet of similar foods and maintaining consistent eating routines throughout the year.8,11,12 For example, 95% of participants report that they eat breakfast and 78% report eating breakfast every day. 13 The most common breakfast reported was cereal and fruit. This is interesting because 25% of average Americans report not being breakfast eaters. 14 It is possible that eating breakfast may prevent overeating later in the day. 13 Additionally, the number of times food was eaten outside the home was limited to about 2.5 times a week. 11 Furthermore, fast food was eaten less than once a week. Finally, participants reported that they do not splurge too much on holidays and special occasions. 12 It is likely that sustaining these eating routines assists participants in maintaining a low-calorie, low-fat diet. These findings also suggest that people who have been overweight and lost weight require a lower calorie diet to maintain weight loss, or these data may reflect people’s tendency to underreport caloric intake.15,16
Self-Monitoring
In addition to eating a consistent diet and maintaining eating routines, registry members reported self-monitoring food intake and weight to maintain weight loss. They continued to use strategies that were employed while attempting to lose weight, such as calorie counting and/or counting of fat grams. 9 Similarly, those using a commercial weight loss program continued to use that system to track food intake in order to achieve weight maintenance. 9 Overwhelmingly, one of the most common behaviors endorsed by registry members was frequent self-weighing either on a weekly or daily basis. 17 It is thought that frequent self-weighing facilitates early identification of weight gain, allowing individuals to make behavioral changes before additional weight gain occurs. A decrease in the frequency of self-weighing has also been shown to be related to increases in caloric and fat intake. This suggests that without feedback regarding energy balance, individuals fail to self-correct.
Physical Activity
The majority of registry members reported using a combination of diet and exercise to maintain weight loss.9,11,18 On average, they watched less than 10 hours a week of television, 19 and engaged in about 60 to 75 minutes a day of moderate physical activity such as brisk walking or 35 to 45 minutes a day of vigorous physical activity such as jogging. 20 US Dietary Guidelines recommend that adults get 60 to 90 minutes a day of moderate-intensity physical activity. However, only about 23% actually met this recommendation, 21 which brings into question whether 60 to 90 minutes of physical activity a day is feasible or even necessary. Furthermore, although the majority of registry members reported high levels of daily physical activity, there is a sizable minority that achieved successful weight maintenance with significantly less weekly physical activity (25% report only getting 30 minutes a day and 15% report only 15 minutes a day). This suggests that there is great variability among individuals for how much physical activity is needed to maintain weight loss and likely depends on individual energy intake.
The strategies employed by members of the National Weight Control Registry are consistent with the recommendations from the current Dietary Guidelines. Basically, it is important to maintain energy balance through focusing on consuming nutrient-dense foods and beverages, reducing intake of nutrient-poor foods, and remaining physically active. However, it is interesting that those who have demonstrated maintenance of weight loss are on average not fully meeting US Dietary Guidelines for food intake or physical activity. Because overweight or obese individuals who have successfully lost weight have to work harder to maintain weight loss and are more vulnerable to weight gain, 22 we would assume that people who are attempting weight loss maintenance would need to do more than what the Dietary Guidelines promote. This is clearly not the case. The strategies used by registry members appear to be more in line with a shaping approach rather than one that strictly follows a predetermined goal. These data suggest that it is not necessarily what you eat or do to maintain a healthy weight, but rather it is important how you support healthy behaviors to more closely approximate the recommendations.
Overall, the National Weight Control Registry studies suggest that perfection is not the goal. A high degree of variability in terms of energy intake and expenditure is found in those maintaining a healthier weight. Although dietary guidelines are not intended to promote weight loss or maintenance of weight loss, they may promote the concept that a strict criterion should be met. Although establishing criterion may be necessary for communicating to the public, health professionals should have an understanding of how to develop individualized behavioral strategies and routines that support gradual behavior change (ie, shaping). Based on the results from the National Weight Control Registry, patients should be encouraged to eat a low-calorie diet, eat a routine diet, self-monitor food intake and weight, and engage in physical activity. Although all the behaviors discussed are consistent with the Dietary Guidelines, it is important to realize that perfect adherence to US Dietary Guidelines (or other recommendations) may not be feasible or necessary for many patients.