Suzanne Phelan

Long-term weight loss maintenance

There is a general perception that almost no one succeeds in long-term maintenance of weight loss. However, research has shown that approximately 20% of overweight individuals are successful at long-term weight loss when defined as losing at least 10% of initial body weight and maintaining the loss for at least 1 y. The National Weight Control Registry provides information about the strategies used by successful weight loss maintainers to achieve and maintain long-term weight loss. National Weight Control Registry members have lost an average of 33 kg and maintained the loss for more than 5 y. To maintain their weight loss, members report engaging in high levels of physical activity ( approximately 1 h/d), eating a low-calorie, low-fat diet, eating breakfast regularly, self-monitoring weight, and maintaining a consistent eating pattern across weekdays and weekends. Moreover, weight loss maintenance may get easier over time; after individuals have successfully maintained their weight loss for 2-5 y, the chance of longer-term success greatly increases. Continued adherence to diet and exercise strategies, low levels of depression and disinhibition, and medical triggers for weight loss are also associated with long-term success. National Weight Control Registry members provide evidence that long-term weight loss maintenance is possible and help identify the specific approaches associated with long-term success.

Consistent Self‐monitoring of Weight: A Key Component of Successful Weight Loss Maintenance

Objective: The objectives were to investigate the characteristics associated with frequent self‐weighing and the relationship between self‐weighing and weight loss maintenance.

Randomized trial of a behavioral intervention to prevent excessive gestational weight gain: the Fit for Delivery Study

BACKGROUND Excessive weight gain during pregnancy is a major risk factor for postpartum weight retention and future weight gain and obesity in women, but few adequately powered randomized controlled trials have examined the efficacy of a behavioral weight-control intervention during pregnancy. OBJECTIVE This study examined whether a behavioral intervention during pregnancy could decrease the proportion of women who exceeded the 1990 Institute of Medicine (IOM) recommendations for gestational weight gains and increase the proportion of women who returned to pregravid weights by 6 mo postpartum. DESIGN This study was a randomized, assessor-blind, controlled trial. Participants were pregnant (13.5 wk gestation), normal-weight (NW; n = 201) and overweight or obese (OW/OB; n = 200) women whose average age was 28.8 y. Participants were randomly assigned within the 1990 IOM weight category (NW compared with OW/OB) to standard care (n = 200) or to a behavioral intervention to prevent excessive gestational weight gain (n = 201). The intervention included one face-to-face visit; weekly mailed materials that promoted an appropriate weight gain, healthy eating, and exercise; individual graphs of weight gain; and telephone-based feedback. The retention at the 6-mo postpartum assessment was 82%. RESULTS Intent-to-treat analyses showed that the intervention, compared with standard care, decreased the percentage of NW women who exceeded IOM recommendations (40.2% compared with 52.1%; P = 0.003) and increased the percentages of NW and OW/OB women who returned to their pregravid weights or below by 6 mo postpartum (30.7% compared with 18.7%; P = 0.005). CONCLUSION A low-intensity behavioral intervention during pregnancy reduced excessive gestational weight gains in NW women and prevented postpartum weight retention in NW and OW/OB women. This trial was registered at clinicaltrials.gov as NCT01117961.

Becoming Physically Active After Bariatric Surgery is Associated With Improved Weight Loss and Health-related Quality of Life

The purpose of this study was to determine whether pre‐ to postoperative increases in physical activity (PA) are associated with weight loss and health‐related quality of life (HRQoL) following bariatric surgery. Participants were 199 Roux‐en‐Y gastric bypass (RYGB) surgery patients. The International Physical Activity Questionnaire (IPAQ) was used to categorize participants into three groups according to their preoperative and /1‐year postoperative PA level: (i) Inactive/Active (<200‐min/week/≥200‐min/week), (ii) Active/Active (≥200‐min/week/≥200‐min/week) and (iii) Inactive/Inactive (<200‐min/week/<200‐min/week). The Medical Outcomes Study Short Form‐36 (SF‐36) was used to assess HRQoL. Analyses of covariance were conducted to examine the effects of PA group on weight and HRQoL changes. Inactive/Active participants, compared with Inactive/Inactive individuals, had greater reductions in weight (52.5 ± 15.4 vs. 46.4 ± 12.8 kg) and BMI (18.9 ± 4.6 vs. 16.9 ± 4.2 kg/m2). Weight loss outcomes in the Inactive/Active and Active/Active groups were similar to each other. Inactive/Active and Active/Active participants reported greater improvements than Inactive/Inactive participants on the mental component summary (MCS) score and the general health, vitality and mental health domains (P < 0.01). Although the direction of causation is not clear, these findings suggest that RYGB patients who become active postoperatively achieve weight losses and HRQoL improvements that are greater than those experienced by patients who remain inactive and comparable to those attained by patients who stay active. Future randomized controlled trials should examine whether assisting patients who are inactive preoperatively to increase their PA postoperatively contributes to optimization of weight loss and HRQoL outcomes.

Weight-loss maintenance in successful weight losers: surgical vs non-surgical methods.

Objective:As large weight losses are rarely achieved through any method except bariatric surgery, there have been no studies comparing individuals who initially lost large amounts of weight through bariatric surgery or non-surgical means. The National Weight Control Registry (NWCR) provides a resource for making such unique comparisons. This study compared the amount of weight regain, behaviors and psychological characteristics in NWCR participants who were equally successful in losing and maintaining large amounts of weight through either bariatric surgery or non-surgical methods.Design:Surgical participants (n=105) were matched with two non-surgical participants (n=210) on gender, entry weight, maximum weight loss and weight-maintenance duration, and compared prospectively over 1 year.Results:Participants in the surgical and non-surgical groups reported having lost approximately 56 kg and keeping ⩾13.6 kg off for 5.5±7.1 years. Both groups gained small but significant amounts of weight from registry entry to 1 year (P=0.034), but did not significantly differ in magnitude of weight regain (1.8±7.5 and 1.7±7.0 kg for surgical and non-surgical groups, respectively; P=0.369). Surgical participants reported less physical activity, more fast food and fat consumption, less dietary restraint, and higher depression and stress at entry and 1 year. Higher levels of disinhibition at entry and increased disinhibition over 1 year were related to weight regain in both groups.Conclusions:Despite marked behavioral differences between the groups, significant differences in weight regain were not observed. The findings suggest that weight-loss maintenance comparable with that after bariatric surgery can be accomplished through non-surgical methods with more intensive behavioral efforts. Increased susceptibility to cues that trigger overeating may increase risk of weight regain regardless of initial weight-loss method.

The role of adherence in mediating the relationship between depression and health outcomes.

Depression has been linked to poor health outcome in a number of studies; however, the mechanism underlying this relationship has received little attention. This paper explores the possibility that adherence mediates the relationship between depression and outcome. Principal findings regarding the relationship between depression, adherence, and outcome are reviewed. The data suggest that depression is related, at least moderately, to poorer adherence to a variety of treatment components. The relationship between adherence and outcome is more difficult to establish. In addition, current data, albeit limited, do not support the hypothesis that adherence mediates the relationship between depression and outcome. An alternative model in which adherence precedes and influences both mood state and health outcome is discussed. Finally, possible explanations for these relationships are explored and suggestions for future research provided.

Physical activity patterns in the National Weight Control Registry.

Objective: The National Weight Control Registry (NWCR) was established in 1993 to examine the characteristics of those who are successful at weight loss: individuals maintaining a 13.6‐kg weight loss for >1 year. The size of the registry has increased substantially since the early descriptions of this group a decade ago. The purpose of this study was to describe in detail the weekly physical activity habits of NWCR members, to examine the relationship between amount of activity and demographic characteristics, and to determine if changes in activity parameters have occurred over time.

Weight-loss maintenance for 10 years in the National Weight Control Registry.

BACKGROUND The challenge of weight-loss maintenance is well known, but few studies have followed successful weight losers over an extended period or evaluated the effect of behavior change on weight trajectories. PURPOSE To study the weight-loss trajectories of successful weight losers in the National Weight Control Registry (NWCR) over a 10-year period, and to evaluate the effect of behavior change on weight-loss trajectories. METHODS A 10-year observational study of self-reported weight loss and behavior change in 2886 participants (78% female; mean age 48 years) in the NWCR who at entry had lost at least 30 lbs (13.6 kg) and kept it off for at least one year. Data were collected in 1993-2010; analysis was conducted in 2012. MAIN OUTCOME MEASURES Weight loss (kilograms; percent weight loss from maximum weight). RESULTS Mean weight loss was 31.3 kg (95% CI=30.8, 31.9) at baseline, 23.8 kg (95% CI=23.2, 24.4) at 5 years and 23.1±0.4 kg (95% CI=22.3, 23.9) at 10 years. More than 87% of participants were estimated to be still maintaining at least a 10% weight loss at Years 5 and 10. Larger initial weight losses and longer duration of maintenance were associated with better long-term outcomes. Decreases in leisure-time physical activity, dietary restraint, and frequency of self-weighing and increases in percentage of energy intake from fat and disinhibition were associated with greater weight regain. CONCLUSIONS The majority of weight lost by NWCR members is maintained over 10 years. Long-term weight-loss maintenance is possible and requires sustained behavior change.

Differential functional magnetic resonance imaging response to food pictures in successful weight-loss maintainers relative to normal-weight and obese controls

BACKGROUND Prior research indicates that successful weight-loss maintainers (SWLs) work harder than people of normal weight to maintain their weight loss, including greater dietary restriction of fat and higher physical activity levels. However, little work to date has examined how SWLs differ biologically from normal-weight (NW) and obese controls. OBJECTIVE The objective was to compare the brain responses of SWLs to food pictures with those of NW and obese controls. DESIGN Blood oxygen level-dependent responses to high- and low-energy food pictures were measured in 18 NW controls, 16 obese controls, and 17 SWLs. RESULTS Group differences were identified in 4 regions, which indicated significant change in activation in response to the food pictures. SWLs showed greater activation in the left superior frontal region and right middle temporal region than did NW and obese controls-a pattern of results confirmed in exploratory voxel-wise analyses. Obese controls also showed greater activation in a bilateral precentral region. CONCLUSIONS These results suggest that SWLs show greater activation in frontal regions and primary and secondary visual cortices-a pattern consistent with greater inhibitory control in response to food cues and greater visual attention to the food cues. A greater engagement of inhibitory control regions in response to food cues as well as a greater monitoring of foods may promote control of food intake and successful weight-loss maintenance.

Maintaining large weight losses: the role of behavioral and psychological factors.

Few studies have examined predictors of weight regain after significant weight losses. This prospective study examined behavioral and psychological predictors of weight regain in 261 successful weight losers who completed an 18-month trial of weight regain prevention that compared a control condition with self-regulation interventions delivered face-to-face or via the Internet. Linear mixed effect models were used to examine behavioral and psychological predictors of weight regain, both as main effects and as interactions with treatment group. Decreases in physical activity were related to weight regain across all 3 groups, and increased frequency of self-weighing was equally protective in the 2 intervention groups but not in the control group. Increases in depressive symptoms, disinhibition, and hunger were also related to weight regain in all groups. Although the impact of changes in restraint was greatest in the Internet group and weakest in the face-to-face group, the latter was the only group with increases in restraint over time and consequent decreases in magnitude of weight regain. Future programs should focus on maintaining physical activity, dietary restraints, and frequent self-weighing and should include stronger components to modify psychological parameters.