Weight Change Two Years after the Termination of the Intensive Lifestyle Intervention in the Look AHEAD Study

Abstract

Objective:

To evaluate weight changes after cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study. We hypothesized that ILI participants would be more likely to gain weight during the 2-year observational period following termination of weight-loss-maintenance counseling than would participants in the Diabetes Support and Education (DSE) control group.

Methods:

Look AHEAD was an RCT that compared the effects of ILI and DSE on cardiovascular morbidity and mortality in participants with overweight/obesity and type 2 diabetes. Look AHEAD was converted to an observational study in September 2012.

Results:

Two years after the EOI, ILI and DSE participants lost a mean±SE of 1.2±0.2 kg and 1.8±0.2 kg, respectively (p=0.003). Thirty-one percent of ILI and 23.9% of DSE participants gained ≥2% (p<0.001) of EOI weight, while 36.3% and 45.9% of the two groups, respectively, lost ≥2% of EOI weight (p=0.001). Two years after the EOI, ILI participants reported greater use of weight-control behaviors than DSE participants.

Conclusions:

Both groups lost weight during the 2-year follow-up period, but more ILI than DSE participants gained ≥2% of EOI weight. Further understanding is needed of factors that affected long-term weight change in both groups.

Clinical trials registration:

NCT00017953

INTRODUCTION

Keeping off lost weight remains a key challenge in the behavioral treatment of obesity. Perri and colleagues demonstrated in a seminal series of studies that participants who lost approximately 8–10 kg with short-term behavioral interventions regained 40% or more of their lost weight in the year following treatment.^1–3 These investigators further showed that providing participants every-other-week weight-loss-maintenance counseling, following initial weight loss, substantially reduced or eliminated this weight regain in maintenance programs that lasted up to 1 year. This was true of counseling provided in person or by phone.⁴ The investigators, however, found that once maintenance sessions ended, participants began to gain weight, suggesting that this counseling only delayed, rather than prevented, weight regain.^1–3 Other researchers have demonstrated the benefits of every-other-week, as well as monthly weight-loss-maintenance sessions, in addition to the problem of weight regain following the termination of such interventions.^5-7

Look AHEAD (Action for Health in Diabetes) was a multi-center, randomized controlled trial that assessed whether intentional weight loss, achieved with an intensive lifestyle intervention (ILI), would reduce cardiovascular morbidity and mortality in participants with type 2 diabetes and overweight or obesity.^8,9 The ILI was designed to induce a mean loss of 7% or more of initial weight the first year and to sustain this loss, with the provision of every-other-week and later monthly weight-loss-maintenance counseling, during an expected follow-up period of 8 to 11.5 years. After the first year of the intervention, ILI participants lost a mean of 8.6% of initial weight, compared with 0.7% for participants randomly assigned to a usual care group (p<.001), referred to as Diabetes Support and Education (DSE).¹⁰

Look AHEAD was stopped on September 14, 2012, based on a futility analysis that found no significant differences between the ILI and the DSE groups on the study’s primary outcome, a composite of death from cardiovascular causes, nonfatal myocardial infarction or stroke, or hospitalization for angina.⁹ At study termination, participants had completed a median of 9.6 years of intervention, with a range of 8.4 years (for the trial’s last enrollees in April 2004) to 11.0 years for the first enrollees (in September 2001). When the intervention ended, ILI participants had a mean loss of 6.0%, as measured from randomization, compared to 3.5% for DSE.⁹

With the termination of the randomized trial, Look AHEAD was converted to an observational cohort study to assess the effects of the ILI, compared to DSE, on a variety of subsequent outcomes. The present report describes changes in body weight in ILI and DSE participants a mean±SD of 2.0±1.1 years (median of 1.6 years) after the end of the intervention. It compares mean differences in weight change (in kg) between groups, as well as the percentages of participants who gained weight (i.e., any amount and ≥2, ≥5, or ≥ 10% of end-of-intervention weight), and the percentages who lost weight (using similar criteria). Based on Perri’s findings, we hypothesized that ILI participants would be more likely than their DSE counterparts to gain weight following termination of weight-loss-maintenance counseling.^3,7,11 The study also examined differences between groups in their self-reported practice of diet and physical activity behaviors, previously shown to be associated with long-term weight loss.^12,13

METHODS

Participants and Procedures

Recruitment and random assignment of Look AHEAD participants have been described previously.^8,14 The study enrolled 5,145 men and women from 2001–2004 at 16 centers across the U.S. Participants were ages 45–76 years and were required to have type 2 diabetes and a body mass index (BMI) ≥25 kg/m² (or ≥27 kg/m² if taking insulin). Participants were randomly assigned in equal numbers to ILI or DSE.

ILI participants received a comprehensive lifestyle intervention that provided one individual and three group (in-person) visits per month for 6 months, followed by one individual and two group visits per month in months 7–12.¹⁵ Participants were prescribed a diet of 1200–1800 kcal/d, based upon body weight, which included the use of meal replacements (e.g., shakes and bars) to help participants achieve their calorie targets.^15–17 In years 2–4, they were provided one individual, in-person visit per month, with an additional monthly contact by telephone, e-mail, or mail. They also were offered optional monthly group meetings, as well as two to three annual refresher groups and national campaigns that focused principally on maintaining the weight losses and high levels of physical activity achieved in year 1.¹⁵ After year 4, participants were provided at least one individual in-person visit per month until the ILI was terminated. They also were encouraged to participate in the optional group meetings described previously.^9,15 Participants in the DSE were invited to three group sessions per year for the first four years, with one annual meeting thereafter.¹⁶

Upon termination of the randomized trial, all participants were informed of the study’s outcome and of the transition to an observational study. All were invited to continue in the Look AHEAD observational follow-up and provided informed consent.

For the present analyses of changes in body weight, participants were included if they completed an annual study assessment 1 year before the end of the intervention (between September 14, 2011 and September 14, 2012) and at least one of two planned assessment visits following the termination of the trial. Participants who had undergone bariatric surgery were excluded.

Study Assessments

Weight and height were assessed, using methods described previously, at approximately annual visits during the first 2 years of the observational study.^8,9 Participants completed questionnaires on physical activity as assessed by the Paffenbarger Activity Questionnaire (PAQ), and self-reported the number of weeks in the prior year in which they engaged in behaviors previously determined to be associated with long-term weight control: 1) increasing physical activity; 2) monitoring body weight; 3) reducing calorie and fat intake; and 4) using meal replacements.^13,18 All participants completed these questionnaires at their 8-year post-randomization assessment and then again at an average of 2.0 years following the end of the intervention (average of 11.7 years post-randomization).

Statistical Analyses

The present analyses focused on the first two visits after the end of intervention (EOI). The baseline visit for this analysis was considered the last visit that occurred in the year prior to the EOI. Models of weight change (in kg) from the baseline EOI visit to visits 1 and 2 years after EOI (during the observational study) were adjusted for race, gender, current age, weight at EOI baseline, and repeated measures. Analyses were also repeated including, as a covariate, the amount of weight lost during the original randomized intervention. Differences between the original ILI and DSE groups in categorical weight changes from the EOI visit to a mean follow-up of 2.0 years were compared using a Chi-squared test. Categories of weight change included any weight gain (≥0%) and gains ≥2%, ≥5%, and ≥10% of EOI weight. Comparable weight loss categories were used (i.e., any loss and ≥2%, ≥5%, and ≥10% of EOI weight). A second analysis further categorized participants as: 1) having remained essentially weight stable during the 2-year period, as indicated by a gain or loss <2% of EOI; 2) having gained weight (i.e., ≥2% gain of EOI weight); or 3) having lost weight (≥2% loss of EOI weight). Similar criteria for weight stability have been used previously.¹⁹

Differences between the ILI and DSE groups in the practice of weight-control behaviors, after the EOI were analyzed using linear regression for continuous variables and logistic regression for categorical variables. Analyses were adjusted for weight change from randomization to EOI and weight change strategy use measured closest to the end of intervention (i.e., year 8). Within each randomization group, similar analyses were also conducted to examine differences in the practice of weight-control behaviors, based on weight stability during the 2-year period (gain or loss <2% of EOI weight), weight gain ≥2% of EOI weight, and weight loss ≥2% of EOI weight. In the linear regression analyses, pairwise tests used the Bonferroni adjustment for multiple comparisons. Correlations between weight change in ILI and DSE in the first 2 years after the EOI and each of the weight-control behaviors were investigated using partial correlation tests, adjusting for weight loss from randomization to the EOI and year 8 behavioral strategy use.

Additional analyses compared mean weight change in the two groups from the study’s original randomization over a mean follow-up of 11.7 years (including a mean of 2 years of follow-up after the EOI). Analyses were adjusted for race, gender, baseline age, and baseline weight in addition to repeated measures. Similar analyses were conducted examining categorical weight changes.

RESULTS

Participant Characteristics

Figure 1 shows the study’s recruitment, randomization, enrollment, and follow-up. Of the 3965 surviving members of the original Look AHEAD study, 3739 participants continued to participate during the observational period and are included in the present analyses. Visits 1 and 2 after the EOI were completed by a similar proportion of participants in ILI (94.9% and 94.4%, respectively) and DSE (93.8% and 93.2%, respectively) (between-group difference after 1 year, p=0.15, after 2 years, p= 0.12).

Figure 1:

The figure shows the CONSORT flow diagram of participants through the approximately 10-year Look AHEAD randomized trial and 2 years following the end of the intervention. ILI = intensive lifestyle intervention; DSE = diabetes support and education. Y1 = Year 1 visit after EOI; Y2 = Year 2 visit after EOI.

The characteristics of these 3739 participants are summarized in Table 1. The table shows their characteristics at the time of randomization to ILI and DSE and again at the EOI. ILI and DSE participants did not differ significantly on characteristics at randomization. At this time, the mean±SD weight for the ILI group was 99.6±19.3 kg, compared with 100.0±18.4 kg for DSE participants. At the EOI, ILI participants weighed 94.1±19.6 kg, which was significantly less than the 97.2±19.8 kg for DSE group (p<0.001).

Table 1.

Participants’ demographic characteristics at randomization, as well as select measures at randomization and at the end of the intervention (N=3739)

	ILI (N=1888)	DSE (N=1851)	P-value
Gender, No. (%)			0.35
Male	773 (40.9%)	730 (39.4%)
Female	1115 (59.1%)	1121 (60.6%)
Race, No. (%)			0.90
African American / Black (not Hispanic)	291 (15.4%)	307 (16.6%)
American Indian / Native American /Alaskan Native	110 ( 5.8%)	110 ( 5.9%)
Asian/Pacific Islander	21 ( 1.1%)	16 ( 0.9%)
White	1176 (62.3%)	1142 (61.7%)
Hispanic	248 (13.1%)	238 (12.9%)
Other/Mixed	42 ( 2.2%)	38 ( 2.1%)
Insulin Use, No. (%)
Randomization			0.92
No	1557 (82.5%)	1526 (82.4%)
Yes	268 (14.2%)	259 (14.0%)
Missing	63 (3.3%)	66 (3.6%)
End of Intervention			0.002
No	1076 (57.0%)	996 (53.8%)
Yes	586 (31.0%)	671 (36.3%)
Missing	226 (12.0%)	184 (9.9%)
Age, mean ± SD, years
Randomization	58.3 ± 6.6	58.6 ± 6.7	0.11
End of Intervention	68.3 ± 6.4	68.6 ± 6.6	0.13
Weight, mean ± SD, kg
Randomization	99.6 ± 19.3	100.0 ± 18.4	0.52
End of Intervention	94.1 ± 19.6	97.2 ± 19.8	<.001
Body Mass Index, mean ± SD, kg/m2
Randomization	35.5 ± 5.9	35.7 ± 5.7	0.21
End of Intervention	33.5 ± 6.0	34.7 ± 6.1	<0.001
Body Mass Index Group, No. (%)
Randomization			0.29
<30 kg/m2	318 (16.8%)	279 (15.1%)
30-<35 kg/m2	690 (36.5%)	656 (35.4%)
35-<40 kg/m2	497 (26.3%)	521 (28.1%)
≥40 kg/m2	383 (20.3%)	395 (21.3%)
End of Intervention			<0.001
<30 kg/m2	587 (31.1%)	422 (22.8%)
30-<35 kg/m2	625 (33.1%)	647 (35.0%)
35-<40 kg/m2	396 (21.0%)	443 (23.9%)
≥40 kg/m2	280 (14.8%)	339 (18.3%)

ILI = intensive lifestyle intervention; DSE = diabetes support and education.

Weight Change After EOI

On average, both the ILI and DSE participants lost weight 2 years after the EOI (Figure 2). ILI participants lost a mean±SE of 1.2±0.2 kg (1.1±0.2%) from EOI to 2 years post-EOI, compared to a significantly greater 1.8±0.2 kg (1.7 ±0.2%) for the DSE group (p=0.003 for kg and p<0.001 for percent weight loss between ILI and DSE). Similar results and statistical conclusions were obtained after adjusting for weight change from randomization to the EOI.

Figure 2:

The figure displays the absolute mean (± SE) kg change at the end of intervention (EOI). The fitted means from models are adjusted for race, gender, current age, weight at end of intervention, and repeated measures. ILI = intensive lifestyle intervention; DSE = diabetes support and education.

Figure 3 shows that over the mean 2 years of follow-up after the EOI, 48.9% and 38.9% of the original ILI and DSE participants, respectively, gained weight (i.e., any amount) (p<0.001). Approximately 31.0% and 23.9% of ILI and DSE participants, respectively, gained ≥2% of EOI weight (p<0.001), 13.9% and 11.6%, respectively, gained ≥5% (p=0.05), and 3.2% and 2.8%, respectively, gained ≥10% (p=0.53). (These values are cumulative. For example, the 31.0% of ILI participants who gained ≥ 2% of EOI weight includes the 13.9% who gained ≥5%.) By contrast, 51.1% of the ILI participants lost weight (i.e., any amount) after the EOI, compared with 61.2% of the DSE group (p<0.001); 36.3% and 45.9% of ILI and DSE participants, respectively, lost ≥2% of EOI weight (p<0.001), 20.1% and 24.4%, respectively, lost ≥5% (p=0.003), and 6.9% and 8.1%, respectively, lost ≥10% of EOI weight (p=0.17). Defining weight stability during the 2-year period as a gain or loss <2% of EOI weight revealed that 32.8% of ILI and 30.2% of DSE participants were weight stable (p<0.001).

Figure 3:

The percentage of participants in the ILI and DSE groups who achieved different categorical weight losses from the end of intervention (EOI) to 2 years after EOI. The percentages are cumulative such that the 20.1% of ILI participants, for example, who lost ≥5% includes the 6.9% who lost ≥10%. ILI = intensive lifestyle intervention; DSE = diabetes support and education.

Correlates of Weight Change After EOI

Weight change after the EOI was significantly associated with weight change during the intervention phase of Look AHEAD (as measured from randomization to the EOI; Rho=−0.19, p<0.001). The correlation between weight change (in kg) from Look AHEAD randomization to the EOI and weight change (in kg) from EOI through the mean 2 years of follow-up after EOI was r=−0.17 (p<0.001) in ILI and r=−0.19 (p<0.001) in DSE. After adjusting for randomization weight (in kg), the correlation between weight change from Look AHEAD randomization to the EOI and the weight change from EOI through 2 years of follow-up after EOI was r=−0.20 (p<0.001) in ILI and r=−0.20 (p<0.001) in DSE. Thus, in both ILI and DSE participants, those who lost more weight during the randomized trial tended to have less weight loss in the 2 years of follow-up after EOI, although these effects were small. In a general linear model, weight change in kg from the EOI through 2 years of follow-up was associated with weight change from randomization to the EOI (β =−0.15, SE=0.01, p<0.001), age (β =−0.06, SE=0.02, p=0.001), female sex (vs male, β =−0.72, SE=0.26, p=0.005), and randomization weight in kg (β =−0.05, SE=0.01, p<0.001). Randomization arm (p=0.12), race (p=0.35), and duration of participation in the Look AHEAD trial (ranging from 8.2 to 11.0 years; p=0.79), were not significantly associated with weight change from EOI through 2 years of follow-up after EOI in these adjusted models.

Practice of Weight Control Behaviors After EOI

Table 2 presents participants’ reports of their physical activity and practice of weight-control behaviors, as assessed 8 years following randomization and a mean of 2 years after the EOI, as well as the change in behaviors over this time. ILI participants, as compared with DSE, reported significantly more physical activity and weight-control behaviors 8 years following randomization. After the EOI, ILI participants continued to report significantly greater weekly energy expenditure (from leisure time physical activity) than DSE participants. However, they did not report trying to increase their physical activity in more weeks of the past year than did DSE participants. ILI participants, compared with DSE, reported using all other weight-control behaviors for a significantly greater number of weeks after the EOI (including reducing calorie and fat intake, using meal replacements, and weighing themselves on a regular basis). However, the frequency with which ILI participants reported practicing these behaviors was significantly less than reported at the 8-year assessment (Table 2). ILI participants, compared with DSE, reported a significantly greater reduction in the practice of all behaviors, except leisure time physical activity, during the EOI follow-up period (all ps<0.001; Table 2). ILI participants were less likely to weigh daily or weekly 2 years after the EOI compared to year 8, while the DSE group showed no difference in odds of daily or weekly self-weighing during the same time period (both ps<0.01).

Table 2.

ILI and DSE participants’ reports of their physical activity, and the number of weeks they used strategies related to calorie restriction, and other weight control behaviors during year 8 of intervention and 2 years following EOI

	Year 8 (n=3322) mean ± SD or n(%)			2 Years after EOI (n=3336) mean ± SD or n(%)			Change from Year 8 to 2 Years after EOI (n=3262) mean (95%CI) or OR(95%CI)
Behavior	DSE	ILI	P-value*	DSE	ILI	P-value*	DSE	ILI	P-value*
Paffenbarger: Leisure	890.4 ± 1309	1088 ± 1604	0.001	668.1 ± 1015	792.9 ± 1160	0.001	−214.5 (−277.2, −151.9)	−304.5 (−384.6, −225.4)	0.08
Time Physical
Activity, kcal/wk,
Increased exercise, weeks in last year	8.7 ± 15.2	11.4 ± 16.7	<0.001	8.8 ± 15.9	8.5 ± 15.4	0.50	0.2 (−0.7, 1.1 )	−3.0 (−4.0, −2.1)	<0.001
Reduced kcal, weeks in last year	11.2 ± 18.0	18.5 ± 20.2	<0.001	12.2 ± 18.7	14.5 ± 19.6	<0.001	1.1 (0.0, 2.2 )	−4.0 (−5.1, −2.8)	<0.001
Reduced fat, weeks in last year	14.3 ± 20.2	21.3 ± 21.8	<0.001	13.9 ± 20.2	16.5 ± 21.3	<0.001	−0.3 (−1.5, 0.9 )	−4.5 (−5.7, −3.4)	<0.001
Used meal replacements, weeks in last year	2.4 ± 8.8	19.1 ± 24.3	<0.001	2.7 ± 9.7	7.7 ± 15.2	<0.001	0.3 (−0.3, 0.8 )	−11.2 (−12.2, −10.2)	<0.001
≥ Daily self-weighing**	245 (15.0%)	594 (35.2%)	<0.001	289 (17.6%)	461 (27.3%)	<0.001	1.21 (1.00, 1.45)	0.69 (0.60, 0.80)	<0.001
≥ Weekly self-weighing**	774 (47.4%)	1220 (72.3%)	<0.001	787 (47.8%)	1071 (63.3%)	<0.001	1.02(0.89, 1.17)	0.66 (0.57, 0.77)	<0.001

^*Student’s T-test for mean ± SD, chi-square for n(%)

ILI = intensive lifestyle intervention; DSE = diabetes support and education

^**Odds(95%CI) of daily or weekly self-weighing at 2 years after EOI in reference to year 8 within treatment group.

Additional analyses within the ILI group revealed that greater practice of self-weighing, as well as reducing calorie and fat intake, reported 2 years following EOI, were associated with losing ≥2% from the EOI to 2 years of follow-up. (Table 3). No other behaviors were related to weight loss during this time. Within DSE, participants who gained ≥2% of EOI weight reported significantly fewer weeks of increased exercise compared to participants who lost ≥ 2% (Table 3). Partial correlations, shown in Table 4, also demonstrated that greater improvements in self-weighing, as well as in the number of reported weeks of reducing calorie and fat intake, were associated with greater weight loss from the EOI to 2 years afterwards. In the DSE group, greater increases in physical activity also were associated with greater weight loss. Correlations were very small (r= −0.05 to −0.13) in all cases.

Table 3.

Weight control behaviors 2 years following EOI for ILI and DSE participants who gained>2%, gained <2% to lost <2%, and lost >2%

	DSE				ILI
Behavior	Lost ≥ 2%	<2% Gain or Loss	Gain ≥ 2%	P-value*	Lost ≥ 2%	<2% Gain or Loss	Gain ≥ 2%	P-value*
Paffenbarger: Leisure Time Physical Activity, kcal/wk, LSMEAN ± SE	715.8 ± 34.6 a	697.2 ± 42.2	558.2 ± 47.8a	0.02	775.4 ± 45.3	852.4 ± 47.3	734.6 ± 48.4	0.21
Increased exercise, weeks in last year, LSMEAN ± SE	10.1 ± 0.6 b	8.9 ± 0.7	6.5 ± 0.8b	0.001	9.4 ± 0.6	8.0 ± 0.6	8.2 ± 0.7	0.24
Reduced kcal, weeks in last year, LSMEAN ± SE	13.5 ± 0.7	11.3 ± 0.8	10.9 ± 0.9	0.04	16.1 ± 0.8c	14.4 ± 0.8	12.9 ± 0.8c	0.02
Reduced fat, weeks in last year, LSMEAN ± SE	14.8 ± 0.7	14.2 ± 0.9	11.9 ± 1.0	0.06	18.2 ± 0.8d	17.0 ± 0.8	14.6 ± 0.9d	0.01
Used meal replacements, weeks in last year, LSMEAN ± SE	2.5 ± 0.3	2.7 ± 0.4	2.7 ± 0.5	0.84	7.3 ± 0.6	7.7 ± 0.6	8.0 ± 0.6	0.75
≥ Daily self-weighing, OR(95%CI)	1.25 (0.89,1.76)	REF	0.81 (0.54,1.22)	0.07	1.44 (1.05,1.97)	REF	0.85 (0.61,1.18)	0.004
≥ Weekly self-weighing, OR(95%CI)	1.27 (0.97,1.66)	REF	0.91 (0.66,1.24)	0.05	1.79 (1.34,2.39)	REF	0.91 (0.68,1.21)	<0.001

ILI = intensive lifestyle intervention; DSE = diabetes support and education

^*linear regression for continuous measures, logistic regression for binary; adjusted for weight loss at end of intervention and year 8 behavioral strategy use

Bonferroni-adjusted comparison tests^a-d with the same super script are significantly different

^ap=0.0241

^bp=0.0006

^cp=0.0138

^dp=0.0091

Table 4.

Partial correlations between weight change in the DSE and ILI from EOI to 2 years afterwards and the change in behaviors from year 8 to 2 years following EOI adjusting for weight loss at EOI and year 8 behavioral strategy use

	DSE		ILI
Behavior	r	P-value*	r	P-value*
Paffenbarger: Leisure Time Physical Activity, kcal/wk, mean ± SD	−0.07	0.01	−0.02	0.54
Increased exercise, weeks in last year, mean ± SD	−0.10	<0.001	−0.03	0.22
Reduced kcal, weeks in last year, mean ± SD	−0.07	0.005	−0.06	0.01
Reduced fat, weeks in last year, mean ± SD	−0.05	0.04	−0.06	0.02
Used meal replacements, weeks in last year, mean ± SD	0.04	0.11	0.02	0.53
≥ Daily self-weighing, n (%)	−0.08	<0.001	−0.08	0.001
≥ Weekly self-weighing, n (%)	−0.08	<0.001	−0.13	<0.001

ILI = intensive lifestyle intervention; DSE = diabetes support and education

^*Pearson correlations for continuous, Spearman non-parametric correlation for binary

Weight Loss from Randomization

Figure 4 presents percentage reduction in baseline weight for the original ILI and DSE participants as measured from randomization to 2 years after the EOI. When the intervention was terminated in September 2012, the 3739 ILI and DSE participants who provided an EOI weight had lost a mean of 5.3 and 2.6% of randomization weight, respectively (p<0.001). Two years after EOI, these two groups achieved mean losses of −6.1% and −4.1% of randomization weight, respectively (p <0.001; see Figure 4). From randomization to 2 years after EOI, a greater percentage of ILI than DSE participants lost ≥5% of body weight (57.2% vs 47.0%; p<0.001; see Figure S1), as well as ≥10% (34.8% vs 27.4%; p<0.001). The ILI group had a significantly smaller percentage of participants who exceeded their randomization weight at 2 years after EOI than did the DSE (23.7% vs 31.0%; p<0.001).

Figure 4:

The figure shows the mean (±SE) weight losses from randomization to 2 years after the end of the intervention for participants randomly assigned to an intensive lifestyle intervention (ILI) or diabetes support and education (DSE; usual care group).

DISCUSSION

ILI participants, on average, lost 1.2 kg during the 2-year observational period following termination of the lifestyle intervention, compared with a mean loss of 1.8 kg for DSE participants. As anticipated, more ILI than DSE participants gained weight during the follow-up period; 31.0% vs 23.9% of these participants, respectively, gained 2% or more of their EOI weight over the 2 years. However, members of Look AHEAD’s lifestyle intervention subcommittee had been concerned that substantially more ILI participants would be vulnerable to weight gain. This concern was based on findings of mean weight regain of 1–2 kg in the first year following termination of approximately 12–15 month weight-loss-maintenance programs.^1-5

Post-EOI weight losses in the ILI group are difficult to interpret in the absence of results from similar long-term (≥5 years) randomized trials of participants with characteristics similar to those of our Look AHEAD sample.^5,20–22 ILI participants, on average, had already regained about 4 percentage points of their first-year weight loss in years 2–5 of the intervention, after which (on average) they began to lose weight again, which continued during the 2-year EOI period (Figure 4). This resumed, late weight loss may have been attributable, in part, to our participants’ relatively older age (i.e., 68 years at the start of the EOI), compared to that of individuals in most prior behavioral weight-loss-maintenance trials (i.e., typically 40–55 years).⁵ Body weight generally increases until about age 60 years, when it tends to plateau and then starts to decrease.²³ Resumed, late weight loss may also be explained by our selection of patients with type 2 diabetes, who typically have not been included in long-term (≥5 years) behavioral weight loss trials. In a prospective, observational study, Looker et al found that individuals gained weight prior to their diagnosis with type 2 diabetes but then, on average, lost weight steadily through up to 25 years of follow-up.²⁴ Similar results have been reported in other cohort studies of patients with type 2 diabetes.^25-27

The mean post-EOI weight loss of 1.8 kg in our DSE participants also is unusual for a control group in a weight-loss maintenance study.⁵ However, the losses are consistent with the prior accelerated reductions in body weight observed in these participants beginning at year 5 of Look AHEAD, as well as with long-term weight losses that may be associated with aging, type 2 diabetes (or other illness), medication use, or other factors, as noted with our ILI participants.^13,23-27

On average, ILI participants had greater declines in the self-reported use of weight-control behaviors 2 years after the EOI than did DSE participants. However, the overall practice of these behaviors was still greater in ILI than DSE participants 2 years after the EOI. Consistent with previous studies, participants in the ILI group who reported more frequent daily or weekly self-monitoring of their weight and more weeks of reducing their calorie and fat intake were more likely to lose weight during the 2-year EOI period.¹² However, associations between weight change and change in behaviors from post-randomization year 8 to 2 years after the EOI were very modest; each variable explained less than 1% of the variance in weight change. The same modest associations were observed in the DSE participants as in the ILI group.

As measured from randomization to 2 years after EOI, ILI participants achieved a mean percentage reduction in initial weight of 6.1%, compared with a significantly smaller 4.1% for DSE. The ILI group has consistently had larger weight losses than the DSE group throughout the randomized trial -- and now after the first 2 years of the observational study. The differences, however, in both mean and categorical weight losses between the two groups have declined steadily since the end of the first year of the intervention, when ILI and DSE had lost 8.6% and 0.7% of randomized weight, respectively.¹⁰ The narrowing of the difference was due in years 2–5 to the previously described mean weight regain in ILI participants (Figure 4).^13,28 Since approximately year 6, the narrowing has been more attributable to accelerated weight loss in the DSE group, which continued to be observed during the 2 year EOI follow-up.¹³ We note that DSE participants were not provided behavioral weight loss counseling at anytime during the 10-year intervention or the present 2-year EOI period, in contrast to participants in the control (placebo) arm of the Diabetes Prevention Program (DPP), who received a group behavioral intervention when that trial was terminated early because of treatment benefit.²¹

Set point theory would suggest that the ILI and DSE weight loss curves will eventually meet, as has been occurring.^29,30 This theory would conjecture that the fall in body weight in the DSE group is the likely consequence of aging, illness, and other factors mentioned previously.^23–27 If the ILI participants had not received the lifestyle intervention, their body weight could have been expected to follow the same pattern of gradual decline observed in the DSE group.

According to set point theory, the lifestyle intervention can be viewed as having driven down participants’ body weight, at the end of the first year of the intervention, below their pre-treatment set point, only to have weight rebound toward the control group’s (DSE’s) weight in years 2–4. This rebound occurred despite ILI participants continuing to be provided weight-loss maintenance counseling during this time. Numerous laboratory studies have demonstrated this weight rebound in food- and weight-restricted animals relative to controls.^31,32

From a long-term perspective, of 15 or more years, the ILI could be viewed as expediting the weight loss that could be expected in an older population of individuals with type 2 diabetes. Even though the ILI and DSE participants may eventually achieve the identical long-term weight losses, the paths by which they achieved weight reduction differed markedly, and weight loss at 1, 4, and 8 years in the ILI was associated with clinically meaningful improvements in sleep apnea, chronic kidney disease, physical mobility, and physical health-related quality of life, as compared to the DSE.^33–36 A critical question that Look AHEAD will ultimately address is whether intentional, substantial weight loss, even if followed by partial weight regain, has a net benefit to overall morbidity and mortality, compared to the pattern of weight change observed in the DSE group.

Study Importance.

What is already known about this subject?

• Keeping off lost weight remains a key challenge in the behavioral treatment of obesity.

• Few studies have assessed changes in weight and weight-control behaviors after termination of long-term (≥5 years) intensive lifestyle interventions.

What are the new findings in your manuscript?

• This study evaluates changes in weight and weight-control behaviors 2 years after the cessation of the 10-year intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study.

• During the 2-year observational period following termination of weight-loss-maintenance counseling, ILI participants lost a mean±SE of 1.2±0.2 kg compared to a significantly greater loss of 1.8±0.2 kg in the Diabetes Support and Education (DSE) control participants.

How might your results change the direction of research or the focus of clinical practice?

• While both groups lost weight, potentially due to participants’ advanced age (i.e., 68 years) and long-term diagnosis of type 2 diabetes, ILI participants reported greater use of weight control behaviors than DSE participants.

Weight Change Two Years after the Termination of the Intensive Lifestyle Intervention in the Look AHEAD Study

Look AHEAD Research Group; Ariana M. Chao, PhD, CRNP; Thomas A. Wadden, PhD; Robert I. Berkowitz, MD; George Blackburn, MD, PhD; Paula Bolin, RN, MC; Jeanne M. Clark, MD, MPH; Mace Coday, PhD; Jeffrey M. Curtis, MD, MPH; Linda M. Delahanty, MS, RDN; Gareth R. Dutton, PhD; Mary Evans, PhD; Linda J. Ewing, PhD; John P. Foreyt, PhD; Linda J. Gay; Edward W. Gregg, PhD; Helen P. Hazuda, PhD; James O. Hill, PhD; Edward S. Horton, MD; Denise K. Houston, PhD; John M. Jakicic, PhD; Robert W. Jeffery, PhD; Karen C. Johnson, MD, MPH; Steven E. Kahn, MB, ChB; William C. Knowler, MD; Anne Kure, BS; Katherine L. Michalski, RD; Maria G. Montez, RN, MSHP, CDE; Rebecca H. Neiberg, MS; Jennifer Patricio, MS; Anne Peters, MD; Xavier Pi-Sunyer, MD; Henry Pownall, PhD; David Reboussin, PhD; Bruce Redmon, MD; W. Jack Rejeski, PhD; Helmut Steinburg, MD; Martha Walker, RD; Donald A. Williamson, PhD, FTOS; Rena R. Wing, PhD; Holly Wyatt, MD; Susan Z. Yanovski, MD; Ping Zhang, PhD

Correspondence: Ariana M. Chao, Ph.D., CRNP, University of Pennsylvania School of Nursing, 418 Curie Blvd, Philadelphia, PA 19104; Tel.: 215–746-7183; Fax: 215–615-1285; Email: arichao@upenn.edu

Look AHEAD Research Group

Members of the writing group included:

Ariana M. Chao, PhD, CRNP; Thomas A. Wadden, PhD; Edward S. Horton, MD; Denise K. Houston, PhD; Steven E. Kahn, MB, ChB; Rebecca Neiberg, MS; Anne L. Peters, MD; F. Xavier Pi-Sunyer, MD; David M. Reboussin, PhD; Rena R. Wing, PhD; Susan Z. Yanovski, MD

Study authors included:

Ariana M. Chao, PhD, CRNP; Thomas A. Wadden, PhD; Robert I. Berkowitz, MD; George Blackburn, MD, PhD; Paula Bolin, RN, MC; Jeanne M. Clark, MD, MPH; Mace Coday, PhD; Jeffrey M. Curtis, MD, MPH; Linda M. Delahanty, MS, RDN; Gareth R. Dutton, PhD; Mary Evans, PhD; Linda J. Ewing, PhD; John P. Foreyt, PhD; Linda J. Gay; Edward W. Gregg, PhD; Helen P. Hazuda, PhD; James O. Hill, PhD; Edward S. Horton, MD; Denise K. Houston, PhD; John M. Jakicic, PhD; Robert W. Jeffery, PhD; Karen C. Johnson, MD, MPH; Steven E. Kahn, MB, ChB; William C. Knowler, MD; Anne Kure, BS; Katherine L. Michalski, RD; Maria G. Montez, RN, MSHP, CDE; Rebecca H. Neiberg, MS; Jennifer Patricio, MS; Anne Peters, MD; Xavier Pi-Sunyer, MD; Henry Pownall, PhD; David Reboussin, PhD; Bruce Redmon, MD; W. Jack Rejeski, PhD; Helmut Steinburg, MD; Martha Walker, RD; Donald A. Williamson, PhD, FTOS; Rena R. Wing, PhD; Holly Wyatt, MD; Susan Z. Yanovski, MD; Ping Zhang, PhD

Look AHEAD Research Group at End of Continuation

Clinical Sites

The Johns Hopkins University

Frederick L. Brancati, MD, MHS¹,^*; Jeanne M. Clark, MD, MPH¹ (Co-Principal Investigators); Lee Swartz²; Jeanne Charleston, RN³; Lawrence Cheskin, MD³; Richard Rubin, PhD³,^*; Jean Arceci, RN; David Bolen; Danielle Diggins; Mia Johnson; Joyce Lambert; Sarah Longenecker; Kathy Michalski, RD; Dawn Jiggetts; Chanchai Sapun; Maria Sowers; Kathy Tyler

Pennington Biomedical Research Center

George A. Bray, MD¹; Allison Strate, RN²; Frank L. Greenway, MD³; Donna H. Ryan, MD³; Donald Williamson, PhD³; Timothy Church, MD³; Catherine Champagne, PhD, RD; Valerie Myers, PhD; Jennifer Arceneaux, RN; Kristi Rau; Michelle Begnaud, LDN, RD, CDE; Barbara Cerniauskas, LDN, RD, CDE; Crystal Duncan, LPN; Helen Guay, LDN, LPC, RD; Carolyn Johnson, LPN, Lisa Jones; Kim Landry; Missy Lingle; Jennifer Perault; Cindy Puckett; Marisa Smith; Lauren Cox; Monica Lockett, LPN

The University of Alabama at Birmingham

Cora E. Lewis, MD, MSPH¹; Sheikilya Thomas, PhD,MPH²; Monika Safford, MD³; Stephen Glasser, MD³; Vicki DiLillo, PhD³; Gareth Dutton, PhD, Charlotte Bragg, MS, RD, LD; Amy Dobelstein; Sara Hannum; Anne Hubbell, MS; Jane King, MLT; DeLavallade Lee; Andre Morgan; L. Christie Oden; Janet Wallace, MS; Cathy Roche, PhD, RN, BSN; Jackie Roche; Janet Turman

Harvard Center

Massachusetts General Hospital.

David M. Nathan, MD¹; Enrico Cagliero, MD³; Heather Turgeon, RN, BS, CDE²; Barbara Steiner, EdM; Valerie Goldman, MS, RDN²; Linda Delahanty, MS, RDN³; Ellen Anderson, MS, RDN³; Laurie Bissett, MS, RDN; Christine Stevens, RN; Mary Larkin, RN; Kristen Dalton, BS, Roshni Singh, BS

Joslin Diabetes Center:

Edward S. Horton, MD¹; Sharon D. Jackson, MS, RD, CDE²; Osama Hamdy, MD, PhD³; A. Enrique Caballero, MD³; Sarah Bain, BS; Elizabeth McKinney, BSN, RN; Barbara Fargnoli, MS,RD; Jeanne Spellman, BS, RD; Kari Galuski, RN; Ann Goebel- Fabbri, PhD; Lori Lambert, MS, RD; Sarah Ledbury, MEd, RD; Maureen Malloy, BS; Kerry Ovalle, MS, RCEP, CDE

Beth Israel Deaconess Medical Center :

George Blackburn, MD, PhD¹; Christos Mantzoros, MD, DSc³; Ann McNamara, RN

University of Colorado Anschutz Medical Campus

James O. Hill, PhD¹; Marsha Miller, MS RD²; Holly Wyatt, MD³, Brent Van Dorsten, PhD³; Judith Regensteiner, PhD³; Debbie Bochert; Gina Claxton-Malloy RD Ligia Coelho, BS; Paulette Cohrs, RN, BSN; Susan Green; April Hamilton, BS, CCRC; Jere Hamilton, BA; Eugene Leshchinskiy; Loretta Rome, TRS; Terra Thompson, BA, Kirstie Craul, RD, CDE; Cecilia Wang, MD

Baylor College of Medicine

John P. Foreyt, PhD¹; Rebecca S. Reeves, DrPH, RD²; Molly Gee, MEd, RD²; Henry Pownall, PhD³; Ashok Balasubramanyam, MBBS³; Chu-Huang Chen, MD, PhD³; Peter Jones, MD³; Michele Burrington, RD, RN; Allyson Clark Gardner, MS, RD; Sharon Griggs; Michelle Hamilton; Veronica Holley; Sarah Lee; Sarah Lane Liscum, RN, MPH; Susan Cantu-Lumbreras; Julieta Palencia, RN; Jennifer Schmidt; Jayne Thomas, RD; Carolyn White; Charlyne Wright, RN; Monica Alvarez, PCT

The University of Tennessee Health Science Center

University of Tennessee East.

Karen C. Johnson, MD, MPH; Karen L. Wilson, BSN; Mace Coday, PhD³; Beate Griffin, RN, BS; Donna Valenski; Polly Edwards; Brenda Fonda; Kim Ward

University of Tennessee Downtown.

Helmut Steinburg, MD³; Carolyn Gresham, BSN; Moana Mosby, RN; Debra Clark, LPN; Donna Green RN; Abbas E. Kitabchi, PhD, MD (retired)

University of Minnesota

Robert W. Jeffery, PhD¹; Tricia Skarphol, MA²; John P. Bantle, MD³; J. Bruce Redmon, MD³; Richard S. Crow, MD³; Scott J. Crow, MD³; Manami Bhattacharya, BS; Cindy Bjerk, MS, RD; Kerrin Brelje, MPH, RD; Carolyne Campbell; Mary Ann Forseth, BA; Melanie Jaeb, MPH, RD; Philip Lacher, BBA; Patti Laqua, BS, RD; Birgitta I. Rice, MS, RPh, CHES; Ann D. Tucker, BA; Mary Susan Voeller, BA

St. Luke’s Roosevelt Hospital Center

Xavier Pi-Sunyer, MD¹; Jennifer Patricio, MS²; Carmen Pal, MD³; Lynn Allen, MD; Janet Crane, MA, RD, CDN; Lolline Chong, BS, RD; Diane Hirsch, RNC, MS, CDE; Mary Anne Holowaty, MS, CN; Michelle Horowitz, MS, RD; Raashi Mamtani, MS

University of Pennsylvania

Thomas A. Wadden, PhD¹; Barbara J. Maschak-Carey, MSN, CDE²; Robert I. Berkowitz, MD³; Gary Foster, PhD³; Henry Glick, PhD³; Shiriki Kumanyika, PhD RD, MPH³; Yuliis Bell, BA; Raymond Carvajal, PsyD; Helen Chomentowski; Renee Davenport; Lucy Faulconbridge, PhD; Louise Hesson, MSN, CRNP; Sharon Leonard, RD; Monica Mullen, RD, MPH

University of Pittsburgh

John M. Jakicic, PhD¹; David E. Kelley, MD¹; Jacqueline Wesche- Thobaben, RN, BSN, CDE²; Daniel Edmundowicz, MD³; Lin Ewing, PhD, RN³; Andrea Hergenroeder, PhD, PT, CCS³; Mary L. Klem, PhD, MLIS³; Mary Korytkowski, MD³; Andrea Kriska, PhD³; Lewis H. Kuller, MD, DrPH³; Amy D. Rickman, PhD, RD, LDN³; Rose Salata, MD³; Monica E. Yamamoto, DrPH, RD, FADA³; Janet Bonk, RN, MPH; Susan Copelli, BS, CTR; Rebecca Danchenko, BS; Tammy DeBruce, BA; Barbara Elnyczky; David O. Garcia, PhD; George A. Grove, MS; Patricia H. Harper, MS, RD, LDN; Susan Harrier, BS; Diane Heidingsfelder, MS, RD, CDE, LDN; Nicole L. Helbling, MS, RN; Diane Ives, MPH; Janet Krulia, RN, BSN, CDE; Juliet Mancino, MS, RD, CDE, LDN; Anne Mathews, PhD, RD, LDN; Lisa Martich, BS, RD, LDN; Meghan McGuire, MS; Tracey Y. Murray, BS; Anna Peluso, MS; Karen Quirin; Jennifer Rush, MPH; Joan R. Ritchea; Linda Semler, MS, RD, LDN; Karen Vujevich, RN-BC, MSN, CRNP; Kathy Williams, RN, MHA; Donna L. Wolf, PhD

The Miriam Hospital/Brown Medical School

Rena R. Wing, PhD¹; Renee Bright, MS²; Vincent Pera, MD³; Deborah Tate, PhD³; Amy Gorin, PhD³; Kara Gallagher, PhD³; Amy Bach, PhD; Barbara Bancroft, RN, MS; Anna Bertorelli, MBA, RD; Richard Carey, BS; Tatum Charron, BS; Heather Chenot, MS; Kimberley Chula-Maguire, MS; Pamela Coward, MS, RD; Lisa Cronkite, BS; Julie Currin, MD; Maureen Daly, RN; Caitlin Egan, MS; Erica Ferguson, BS, RD; Linda Foss, MPH; Jennifer Gauvin, BS; Don Kieffer, PhD; Lauren Lessard, BS; Deborah Maier, MS; JP Massaro, BS; Tammy Monk, MS; Rob Nicholson, PhD; Erin Patterson, BS; Suzanne Phelan, PhD; Hollie Raynor, PhD, RD; Douglas Raynor, PhD; Natalie Robinson, MS, RD; Deborah Robles; Jane Tavares, BS

The University of Texas Health Science Center at San Antonio

Helen p. Hazuda, PhD¹;Maria G. Montez, RN, MSHP, CDE²; Carlos Lorenzo, MD³; Charles F. Coleman, MS, RD; Domingo Granado, RN; Kathy Hathaway, MS, RD; Juan Carlos Isaac, RC, BSN; Nora Ramirez, RN, BSN

VA Puget Sound Health Care System / University of Washington

Steven E. Kahn, MB, ChB¹; Anne Kure, BS²; Edward J. Boyko, MD, MPH³; Edward Lipkin, MD, PhD³; Dace Trence, MD³; Subbulaxmi Trikudanathan, MD, MRCP, MMSc³; Elaine Tsai, MD³; Brenda Montgomery, RN, MS, CDE; Ivy Morgan-Taggart; Jolanta Socha, BS; Lonnese Taylor, RN, BS; Alan Wesley, BA

Southwestern American Indian Center, Phoenix, Arizona and Shiprock, New Mexico

William C. Knowler, MD, DrPH¹; Paula Bolin, RN, MC²; Tina Killean, BS²; Maria Cassidy-Begay, BSND, RND ²; Katie Toledo, MS, LPC²; Cathy Manus, LPN³; Jonathan Krakoff, MD³; Jeffrey M. Curtis, MD, MPH³; Sara Michaels, MD³; Paul Bloomquist, MD³; Peter H. Bennett, MB, FRCP³; Bernadita Fallis, RN, RHIT, CCS; Diane F. Hollowbreast; Ruby Johnson; Maria Meacham, BSN, RN, CDE; Christina Morris, BA; Julie Nelson, RD; Carol Percy, RN, MS; Patricia Poorthunder; Sandra Sangster; Leigh A. Shovestull, RD, CDE; Miranda Smart; Janelia Smiley; Teddy Thomas, BS

University of Southern California

Anne Peters, MD; Siran Ghazarian, MD; Elizabeth Beale, MD; Kati Konersman, RD, CDE; Brenda Quintero-Varela; Edgar Ramirez; Gabriela Rios, RD; Gabriela Rodriguez, MA; Valerie Ruelas MSW, LCSW; Sara Serafin-Dokhan; Martha Walker, RD

Coordinating Center

Wake Forest University

Mark A. Espeland, PhD¹; Judy L. Bahnson, BA, CCRP³; Lynne E. Wagenknecht, DrPH¹; David Reboussin, PhD³; W. Jack Rejeski, PhD³; Alain G. Bertoni, MD, MPH³; Wei Lang, PhD³; David Lefkowitz, MD³; Patrick S. Reynolds, MD³; Denise Houston, PhD³; Mike E. Miller, PhD³; Laura D. Baker, PhD³; Nicholas Pajewski, PhD³; Stephen R. Rapp, PhD³; Stephen Kritchevsky, PhD³; Haiying Chen, PhD, MM³; Valerie Wilson, MD³; Delia S. West, PhD³; Ron Prineas, MD³; Tandaw Samdarshi, MD³; Amelia Hodges, BS, CCRP²; Karen Wall²; Carrie C. Williams, MA, CCRP²; Andrea Anderson, MS; Jerry M. Barnes, MA; Tara D. Beckner; Delilah R. Cook; Valery S. Effoe, MD, MS; Melanie Franks, BBA; Katie Garcia, MS; Sarah A. Gaussoin, MS; Candace Goode; Michelle Gordon, MS; Lea Harvin, BS; Mary A. Hontz, BA; Don G. Hire, BS; Patricia Hogan, MS; Mark King, BS; Kathy Lane, BS; Rebecca H. Neiberg, MS; Julia T. Rushing, MS; Debbie Steinberg, BS; Jennifer Walker, MS; Michael P. Walkup, MS;

Central Resources Centers

Central Laboratory, Northwest Lipid Metabolism and Diabetes Research Laboratories

Santica M. Marcovina, PhD, ScD¹; Jessica Hurting²; John J. Albers, PhD³, Vinod Gaur, PhD⁴

ECG Reading Center, EPICARE, Wake Forest University School of Medicine

Elsayed Z. Soliman MD, MSc, MS¹; Charles Campbell ²; Zhu-Ming Zhang, MD³; Mary Barr; Susan Hensley; Julie Hu; Lisa Keasler; Yabing Li, MD

Hall-Foushee Communications, Inc.

Richard Foushee, PhD; Nancy J. Hall, MA

Federal Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases

Mary Evans, PhD; Van S. Hubbard, MD, PhD; Susan Z. Yanovski, MD

National Heart, Lung, and Blood Institute

Lawton S. Cooper, MD, MPH; Peter Kaufman, PhD, FABMR; Mario Stylianou, PhD

Centers for Disease Control and Prevention

Edward W. Gregg, PhD; Ping Zhang, PhD

Funding and Support

Funded by the National Institutes of Health through cooperative agreements with the National Institute of Diabetes and Digestive and Kidney Diseases: DK57136, DK57149, DK56990, DK57177, DK57171, DK57151, DK57182, DK57131, DK57002, DK57078, DK57154, DK57178, DK57219, DK57008, DK57135, and DK56992. Additional funding was provided by the National Heart, Lung, and Blood Institute; National Institute of Nursing Research; National Center on Minority Health and Health Disparities; NIH Office of Research on Women’s Health; and the Centers for Disease Control and Prevention. This research was supported in part by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases. The Indian Health Service (I.H.S.) provided personnel, medical oversight, and use of facilities. The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the I.H.S. or other funding sources.

Additional support was received from The Johns Hopkins Medical Institutions Bayview General Clinical Research Center (M01RR02719); the Massachusetts General Hospital Mallinckrodt General Clinical Research Center and the Massachusetts Institute of Technology General Clinical Research Center (M01RR01066); the Harvard Clinical and Translational Science Center (RR025758–04); the University of Colorado Health Sciences Center General Clinical Research Center (M01RR00051) and Clinical Nutrition Research Unit (P30 DK48520); the University of Tennessee at Memphis General Clinical Research Center (M01RR0021140); the University of Pittsburgh General Clinical Research Center (GCRC) (M01RR000056), the Clinical Translational Research Center (CTRC) funded by the Clinical & Translational Science Award (UL1 RR 024153) and NIH grant (DK 046204); the VA Puget Sound Health Care System Medical Research Service, Department of Veterans Affairs; and the Frederic C. Bartter General Clinical Research Center (M01RR01346). AMC was supported, in part, by the National Institute of Nursing Research of the National Institutes of Health under Award Number K23NR017209.

The following organizations have committed to make major contributions to Look AHEAD: FedEx Corporation; Health Management Resources; LifeScan, Inc., a Johnson & Johnson Company; OPTIFAST® of Nestle HealthCare Nutrition, Inc.; Hoffmann-La Roche Inc.; Abbott Nutrition; and Slim-Fast Brand of Unilever North America.

Some of the information contained herein was derived from data provided by the Bureau of Vital Statistics, New York City Department of Health and Mental Hygiene.