A longitudinal study to investigate the effects of a 12-week comprehensive lifestyle weight management program on body weight and quality of life

Abstract

Background & Aims

The majority of Americans now have overweight or obesity. With limited resources to treat all patients, group programs are emerging as an efficient method for dissemination of evidence-based lifestyle information. The objective of this study was to evaluate change in body weight, biochemical parameters, and quality of life among individuals after completion of a 12-week comprehensive group weight management program at an obesity medicine clinic.

Methods

204 patients were recruited for the study after enrolling in the Healthy Habits for Life program at the Massachusetts General Hospital Weight Center in Boston and Danvers, MA. Prior to the program, patients met individually with a dietitian and baseline data was collected. Primary outcome measures collected were weight and BMI change over the course of the program. Secondary measures collected included biochemical parameters and quality of life. Weekly group visits consisted of primary outcome collection and 1.5 hours of instruction on various lifestyle- and nutrition-related topics. Secondary outcome measures were reassessed at an individual visit with the dietitian after the program concluded.

Results

142 participants were adherent to the protocol (attended 9 out of 12 classes). On average, patients lost 6.4 kg (14.1 lbs.), representing a percent total body weight loss of over 5%. Average BMI decrease was significant at 5.35±4.61%. Improvements were seen in physical function, self-esteem, and sexual life; total QOL scores also improved by a significant 5.79% on average. There were also significant improvements in total cholesterol, triglycerides, and HbA1c.

Conclusions

The Healthy Habits for Life group program was an effective treatment for obesity and related health concerns, including overall quality of life. Group programs of this style may be a more efficient was to disseminate evidence-based lifestyle information and affect change for patients with overweight or obesity.

Introduction

Obesity is a medical condition defined by the storage of excess body fat. The latest statistics show that 39% of the world’s adult population has overweight, and 13% have obesity¹; the numbers are much higher in the United States². Causes of obesity are complex and currently poorly understood, despite intensive research, and include genetic, developmental, and environmental components that cause aberrations in the energy homeostasis system³.

Though weight loss through lifestyle change alone typically result in lower magnitudes of weight loss compared to interventions that also include anti-obesity medications (AOM) or bariatric surgery, even moderate weight loss can lead to an improvement in metabolic issues related to obesity². A sustained weight loss of just 3%−5% is likely to lead to clinically significant health improvements such as reductions in triglycerides, blood glucose, and HbA1c, and is linked to a reduced risk of developing type II diabetes, heart disease, osteoarthritis, obstructive sleep apnea, nonalcoholic fatty liver disease, and many forms of cancer, among other diseases. Improvements such as these can thereby also reduce the need for medications to treat or prevent obesity-related diseases⁴. The recommended method for facilitating this sustained weight loss is through a comprehensive lifestyle program that includes diet, physical activity, and behavior modification⁵.

Individuals with overweight or obesity who would benefit from weight loss should participate in an “intensive lifestyle intervention” (ILI) program including 14 or more sessions over a 6-month period led by a trained interventionist, such as a registered dietitian^5,6. ILI should address instruction on creating a calorie deficit, incorporation of at least 150–180 minutes of moderate intensity aerobic activity per week, self-monitoring of food intake, physical activity, and weight, and improvement of health- and weight-related behaviors. Frequent contact with the interventionist is critical⁵. Food records or other record-keeping and adherence to a program are also associated with better outcomes⁵. While it may seem counter-intuitive, studies show that group behavioral education is just as effective, if not more effective, than individual nutrition visits for weight loss. It has long been known that individual therapy and group therapy can produce similar weight loss, but in 2001, Renjilian and colleagues showed that regardless of patient preference, group intervention may actually result in superior weight loss⁷; Paul-Ebhohimhen and colleagues confirmed this in a 2009 systematic review⁸. Advantages included increased social support and more comprehensive education. Group therapy produced a “clinically significant” reduction of 10% in body weight in 45% of participants, while only 29% of participants in individual therapy achieved this goal. Fortunately, group treatment is also a more efficient use of resources for the clinic or center delivering the intervention⁷.

The objective of this study was to evaluate change in body weight, biochemical parameters and quality of life among individuals after completion of an established 12-week comprehensive group weight management program at an obesity medicine clinic. We hypothesized that participants would lose weight, achieve improvements in biochemical parameters, and report improved quality of life measures after program completion. From these findings, we hope to help other healthcare providers and centers implement successful weight loss programs.

Subjects and Methods

Participants were adult patients at the Massachusetts General Hospital Weight Center between the ages of 21 to 80 years with a BMI between 28.5 and 74.4 kg/m². Researchers first ran a 3-month pilot study to test the feasibility and efficacy of this intervention before expanding the program to a larger group due to the time and financial investments involved in such a program, especially for an obesity medicine clinic with limited resources and personnel. Thirty-six participants were enrolled in a 12-week behavioral weight loss group program, Healthy Habits for Life (HHL). Of these 36, 12 completed the program (with 8 participants who dropped out and 12 who had not yet completed the program at the time of data analysis). All patients who were enrolled in the HHL program during the study period were recruited for the research study, were given detailed information about the study, and, if they chose to participate, were asked for their informed consent. Quality of life, biochemical parameters and weight loss were measured pre- and post-completion of the program. In the full study, patients entering the MGH Weight Center medical pathway were given the option to join the HHL program and could opt-in to participation in the study.

All participants had an individual visit with a registered dietitian prior to beginning the group as part of standard care. At this visit, the dietitian obtained informed consent for participation in the research study. Participants underwent indirect calorimetry (MedGem®) in a fasted, rested state (no food or caffeine 4 hours prior, test administered in a comfortable dark room before 9:00 AM), which was interpreted and used to set specific daily kilocalorie recommendations with the goal of ½−2 lbs. of weight loss per week. Participants were oriented to the group program and instructed on keeping a food records. Once enrolled in the program, the participants attended 12 sessions focused on lifestyle modification, including topics such as basic nutrition, mindful eating, cognitive behavioral therapy, and physical activity (Table 1). After completion of the 12 HHL group sessions, all participants were scheduled for an individual visit with the dietitian and a physician to review weight and behavior changes since the initial evaluation.

Table 1:

Class topics covered in the Healthy Habits for Life curriculum.

Food Records	Grocery Shopping and Labels	Behavior Change
Healthy Nutrition	Dining Out	Meal Planning and Culinary Skills
Portions and Volumetrics	Etiology of Obesity	Physical Activity
Mindfulness	Evaluating Popular Diets	Long-term Weight Management

Primary outcome measures collected were weight and BMI change over the course of the program. Secondary measures collected included biochemical parameters (total glucose, alanine transaminase [ALT], aspartate transaminase [AST], total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, HbA1C) and quality of life (using the validated IW-QOL-Lite© questionnaire). Height was collected at the participant’s first visit to the Weight Center by a medical assistant using a stadiometer (Seca, mod 240). Weight was collected at every visit (at pre-and post- group individual sessions by a medical assistant on Detecto scale, and at each weekly group session by self-report on the same scale); biochemical parameters and the IW-QOL-Lite© Questionnaire⁹ were obtained both pre- and post-completion of the group program. The IW-QOL-Lite© was filled out on paper by patients prior to their pre- and post-program appointments and included 31 questions covering the areas of Physical Function, Self Esteem, Sexual Life, Public Distress, and Work Life⁹. Blood samples for biochemical parameters were collected in a fasted state prior to the start of the program, but blood samples collected at the conclusion of the program were not required to be fasted. A schematic of the participants’ progression through the program is shown in Figure 1.

Figure 1:

Flow diagram of the HHL program process

Abbreviations: Healthy Habits for Life (HHL); Registered Dietitian (RD); Anti-obesity Medications (AOM)

Data was collected and deidentified using REDCap©. Data was analyzed using JMPV.13.0 for analyses and data is presented as means±SD or median (interquartile range). Paired T-tests were used to compare baseline and follow-up parameters pre- and post-completion of the group program. Wilcoxon Test was used for non-normally distributed data. Pilot results were first analyzed after 3 months of classes (one 12-week HHL class in total); full study results were analyzed after 3 years of data collection, encompassing many consecutive rounds of the 12-week intervention at the two site locations. This study was approved by the Institutional Review Board (IRB) of Partners Healthcare.

Results

After 3 years of data collection, 142 participants were adherent to the protocol (attended 9 out of 12 classes) out of 204 total participants; 97 participants completed at least 9 classes and the post-HHL session, including repeat biochemical parameters (Figure 2). Aside from the number of classes attended, there are no major differences between all participants and the participants who were adherent to the protocol (Table 2).

Figure 2:

Flow diagram of patients’ participation in the study

Abbreviations: Healthy Habits for Life (HHL); Registered Dietitian (RD)

Table 2:

Clinical characteristics of all participants and adherent participants at baseline

Characteristics		All Participants n=204	Patients adherent* to protocol n=142
Average # sessions attended		8.31±4.11	10.70±1.06
Age (years)		52 (41–60)	54 (39–62)
Sex	Male	62 (31%)	45 (32%)
	Female	141 (69%)	97 (68%)
Height (cm)		167.01 (161.29–175.26)	168.28 (162.40–177.8)
Weight (kg)		108.82 (96.38–125.95)	108.82 (97.07–124.87)
BMI (kg/m²)		38.3 (35.3–42.1)	38.2 (35.4–42.0)
Race	White	167 (82%)	122 (86%)
	Black	9 (4%)	6 (4%)
	Asian	3(2%)	2 (1%)
	Unknown	25 (12%)	12 (9%)
Glucose (mg/dL)		95 (86–109) (n=198)	95 (85.8–109.3) (n=138)
ALT (U/L)		23 (17–36) (n=199)	22 (18–27) (n=138)
AST (U/L)		23 (18–28) (n=198)	23 (18–28) (n=138)
Cholesterol (mg/dL)		191.41±36.68 (n-194)	193.55±34.16 (n-135)
Triglycerides (mg/dL)		116.5(81.8–147.3) (n=194)	115(84–142) (n=135)
HDL (mg/dL)		49 (39.8–59.0) (n=194)	49 (39 −59) (n=135)
LDL (mg/dL)		114.58 ±32.17 (n=186)	115.91 ±30.95 (n=130)
HbA1c (%)		5.6 (5.4–6) (n=192)	5.6 (5.4–6.1) (n=133)
On
Anti-Obesity Medication
None		171 (84%)	119 (83%)
Metformin		18 (9%)	11 (8%)
Bupropion		7 (3%)	5 (4%)
Qysmia		0	0
Phentermine		3 (1.5%)	1 (0.1%)
Topiramate		3 (1.5%)	2 (0.1%)
Bupropion+Naltrexone		1 (0.1%)	1 (0.1%)
Liraglutide		1(0.1%)	1(0.1%)
Lorcaserin		0	0
Zonisamide		0	0
Exenitide		0	0
Orlistat		0	0
Pramlintide		0	0

^*Adherent is defined as attending 9 out of 12 classes.

Data presented as means±SD or median (interquartile range).

Abbreviations: ALT- alanine transaminase, AST- aspartate transaminase, HDL-high density lipoprotein, LDL- low density lipoprotein

At baseline, participants were an average of 54 years old and had an average BMI of 38.2 (35.4–42.0) kg/m² (moderate obesity). The group was 86% white and 68% female. On average, participants were within normal limits for the biochemical parameters assessed prior to the program initiation, indicating that metabolically, this population was healthy overall. At the start of the program, only 12.4% of adherent participants were using an AOM (Table 2).

At the end of the 12-week program, all participants were asked to repeat the measures taken prior to starting the group, including weight, BMI, biochemical parameters (ALT, AST, total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, HbA1C, total glucose and insulin) and quality of life (using the validated IWQOL-Lite© questionnaire). Weight, BMI, and self-esteem measures all improved, but multiple other factors improved significantly as well (Table 3). Full statistical analysis was limited to only participants who were adherent to attending at least 75% of all classes.

Table 3:

Patients adherent to HHL protocol saw improvement in various clinical markers and quality of life scores

Weight Change	Pre-group average* (n=121)	Post-group average* (n=55)	Percent Total Weight Lost* (%, n=51)	p-value
BMI (kg/m2)	38.1 (35.1–42.2)	35.6 (32.5–40.2)	−5.35±4.61	0.0002†
Weight (Kg)	109.0 (96.9–127.5)	102.60 (90.2–115.7)	−5.35±4.61	0.005†
QOL Scores	Pre-group	Post-group	Percent Change	p-value
Total	69.2 (57.7–80.8) (n=120)	79.8 (68.2–89.0) (n=47)	5.79 (−3.83–20.14) (n=45)	0.005†
Physical Function	66(50–77) (n=120)	77.3 (61–87) (n=47)	9.43 (−3.83–29.07) (n=45)	0.002†
Self Esteem	55.5 (33.0–74.1) (n=120)	71.4 (50.0–82.1) (n=47)	8.55 (−7.08–30.95) (n=44)	0.0014†
Sexual Life	75 (50–94) (n=116)	87.5 (65.9–100.0) (n=45)	0 (−2.01–33.33) (n=42)	0.01†
Public Distress	85 (65–100) (n=119)	87.5 (73.8–95.0) (n=46)	0 (−5.19–15.38) (n=44)	0.497†
Work Life	88(69–100) (n=120)	100 (76.5–100) (n=44)	3.19 (0–19.13) (n=42)	0.117†
Biochemical Markers	Pre-group	Post-group	Percent Change	p-value
Glucose (mg/dL)	94 (85.5–107.5) (n=117)	94 (85.3–105) (n=48)	−2.56 (−10.71–2.93) (n=42)	0.501†
ALT (U/L)	22 (17–32) (n=118)	22 (16–27) (n=49)	−12.5 (−29.17–0) (n=43)	0.228†
AST (U/L)	22 (17–27) (n=117)	21(18–24.5) (n=49)	−4.54 (−15–5.88) (n=43)	0.719†
Cholesterol (mg/dL)	195.5±34.52 (n-114)	179.8±41.88 (n=49)	−70.64±7.91 (n=41)	0.013
Triglycerides (mg/dL)	115.5(84–142.5) (n=114)	103 (65–125) (=49)	0 (−17.88–20.29) (n=41)	0.018†
HDL (mg/dL)	49 (39–59) (n=114)	53 (44–62) (n=49)	−2.13 (−10.58–4.45) (n=41)	0.333†
LDL (mg/dL)	117.04 ±31.31 (n=110)	109.04±32.33 (n=47)	−1.50±13.97 (n=39)	0.153
HbA1c (%)	5.6 (5.4–6.0) (n=133)	5.5 (5.2–5.7) (n=47)	−1.82 (−5.34–0) (n=41)	0.035†

^*Patients on weight loss medications were excluded to isolate the effects of the HHL program. Data presented as means±SD or median (interquartile range). Paired T-tests were used to compare baseline and follow-up parameters pre- and post-completion of the group program.

^†Wilcoxon Test was used for non-normally distributed data.

Abbreviations: ALT- alanine transaminase, AST- aspartate transaminase, HDL-high density lipoprotein, LDL- low density lipoprotein

In the final analysis, patients on anti-obesity medications (at final analysis, 119 of the remaining patients, or 83%; see Table 2) were excluded to isolate the effects of the behavioral program. On average, patients lost 6.4 kg (14.1 lbs.), representing a percent total body weight loss of over 5% (Table 3). In sum, 37% of participants lost over 5% of their body weight, and 18% of participants lost over 10% of their starting body weight (not shown). Average BMI decrease was significant 5.35±4.61% (Table 3).

Significant changes were seen in several quality of life matters and biochemical parameters. Improvements were seen in physical function, self-esteem, and sexual life; total QOL scores also improved by a significant 5.79% on average. While the group as a whole began in a metabolically healthy state, there were still significant improvements in total cholesterol, triglycerides, and HbA1c (Table 3).

As a final analysis, BMI change and percent weight loss were stratified by several factors that may have influenced the outcomes, which were not accounted for in the above analyses; patients included were all patients completing the final post-HHL visit and biochemical parameter measurement (Table 4). Adherence, defined as attending at least 9 out of the 12 visits, is well-documented in its relationship with weight change in lifestyle-based interventions; here, we did not see a relationship, potentially because of the small number of participants who did not attend at least 9 sessions. Keeping food records or participating in some other form of self-monitoring is also associated with losing significantly more weight than making lifestyle changes without record-keeping; that relationship was also not upheld here. Finally, it would logically follow that the use of AOM would affect weight change; this analysis also did not show significant differences (not shown), possibly due to small sample size.

Table 4:

Primary outcome measures stratified by possible influencing factors

Stratified BMI changes and percent total body weight loss:	Percent Difference in BMI change		p-value	Percent Difference in Weight loss		p-value
	Yes (%)	No (%)		Yes (%)	No (%)
Completing the program per protocol? (9/12 visits and final visit)	2.41±2.3 6 (n=97)	1.09±1.2 1 (n=7)	0.147	6.14±5.6 8 (n=97)	2.59±2.9 8 (n=7)	0.106
Kept food records? (9/12 visits)	2.20±1.8 9 (n=54)	2.46±2.7 3 (n=50)	0.579	5.79±4.9 6 (n=54)	6.02±6.2 9 (n=50)	0.839
On anti-obesity medications at Pre-HHL and Post-HHL	2.70±2.7 2 (n=49)	1.99±1.8 6 (n=55)	0.123	6.72±6.4 3 (n=49)	5.17±4.7 0 (n=55)	0.162

Data presented as means±SD. Paired T-tests were used to compare baseline and follow-up parameters pre- and post-completion of the group program. Wilcoxon Test was used for non- normally distributed data.

Abbreviations: Healthy Habits for Life (HHL)

Discussion

Eight-year data from the largest US ILI study, the Look AHEAD study, showed successful long-term weight loss maintenance with intensive lifestyle intervention focused on a primary outcome of decreasing cardiovascular morbidity and mortality as compared to a usual care Diabetes Support and Education (DSE) group¹¹. The percent of total body weight lost (TBWL) during the Healthy Habits for Life (HHL) program is in line with the results seen in other intensive lifestyle interventions like Look AHEAD (ILI)^5,10,11, even without the use of anti-obesity medications, meal replacements, or virtual contact between visits that other ILI programs have used. Unfortunately, without a control group or intention-to-treat analysis, there is no way to rule out regression to the mean as a factor among participants’ success in weight loss and other improvements. Interestingly, we did not observe any differences weight loss or BMI change between patients meeting attendance goals, keeping food records, or taking weight loss medications, and those who were not, though one would expect to see these factors associated with greater change over time. Potential reasons for this include small sample size, self-reporting errors, or the relatively short duration of the program.

Qualitatively speaking, the improvement in overall quality of life, in addition to several individual QOL factors, is a meaningful result of this program. The participants were, on average, metabolically healthy, so many of them were participating in the program to see improvements that are not directly reflected by health status. Individual patients reported improvements in their relationships with themselves and their body image, with their coworkers and families, and with the food they eat. Improved self-esteem and self-efficacy may help patients settle into their healthier lifestyle long-term, prolonging and amplifying the mental, emotional, and physical benefits of an ILI program¹².

Several other studies support the effectiveness of group therapy for behavior change outside the realm of weight loss and can provide more information about the duration, intensity, and content of the most effective programs. Strid and colleagues performed a meta-analysis of various ILIs for the management of coronary heart disease, organized by duration (more than or less than 3 months), intensity (more or less than 20 contacts), and included content (exercise, diet, behavior, and self-care). More significant positive results were found in higher-intensity programs, especially when the contacts were more frequent at the start of the program and spaced out more towards the end of the program. Better results were also found with programs of longer duration and increased success was also associated with more comprehensive and well-rounded educational content¹³. After completion of the programs, it is recommended that patients continue with regular follow up to maintain the lifestyle changes¹³.

One improvement that could be made to the HHL program is the addition of intermittent visits (i.e. every other month) to address weight maintenance for at least one year following the completion of the program¹⁴; unfortunately, many patients were lost to follow up after the completion of the 12 group sessions. Patients often discover that avoiding weight regain is just as difficult, if not more so, than losing weight, and should have support from trained interventionists during this time⁵. The human body adapts to weight loss by lowering the resting metabolic rate and changing hormone levels related to hunger and satiety, which, along with an obesogenic environment, makes weight maintenance very difficult³. As part of the program, there should be an assessment of weight loss maintenance at 6- and 12-months post-completion of the group to provide valuable information on the longer-term impact of the group⁵.

Even close to a decade after the Look AHEAD trial began, participants in the ILI group maintained benefits associated with weight loss, including increased cardiorespiratory fitness and quality of life, better blood glucose control, reduced cardiovascular risk factors¹⁵, and disability-free lifespan¹⁶; even if HHL participants struggle to maintain the weight lost, they may experience similar benefits over time. The HHL program begins to address long-term visits by including a post-group follow up with an RD and obesity medicine physician, where patients are encouraged to continue visiting the clinic at regular intervals. Fortunately, this study shows that a group program of only 3 months, which may be more realistic to implement than a 12-month ILI for many clinics and less overwhelming to patients, still helps set patients along the right path. However, HHL does not currently address long-term weight maintenance; though patients are strongly encouraged to continue visiting the MGH Weight Center or enroll in other weight management programs, there is no formalized process for ensuring patients have all the tools they need to maintain weight after completion of HHL.

A sustained weight loss of 3–5% is associated with improvements in blood lipid levels, blood glucose levels, blood pressure, sleep apnea, joint pain, and many other weight-related risks². This type of improvement was seen in the HHL population, despite the population as a whole being metabolically healthy at the start of the program. This is in contrast to other ILI programs like Look AHEAD and DPP, as those programs are specifically targeting cardiac disease and diabetes, respectively, through lifestyle change and weight loss^11,15. Therefore, HHL is distinct in showing that weight loss can improve metabolic parameters and potentially prevent the onset of these conditions, rather than treating the diseases after they have already arisen. Of note, the pre-HHL blood samples biochemical parameters were drawn in a fasted state while the post-HHL were not fasting, which may mean that the actual improvements were larger or different than those observed.

A major challenge in all weight loss interventions, including HHL, is pairing the right weight loss treatment with the right patient. Post-hoc analysis of the Look AHEAD study shows heterogeneity among responses to treatment. For example, the analysis found that Hispanic and African American participants achieved greater weight loss with greater session attendance, but greater meal replacement use actually decreased weight loss magnitude among African American women compared to all other racial/ethnic and sex subgroups¹⁷. There appears to be a relationship between previous weight loss success¹⁸, older age, and greater initial weight loss¹⁹ with increased long-term weight loss, which may help predict which patients will do best even after the program has concluded. The HHL program has tried to address this challenge by requiring a post-group 1:1 visit with a dietitian and an obesity medicine physician to review achievements and create a plan for ongoing obesity treatment.

Other barriers for ILI programs like HHL include limited resources, including time and qualified interventionists. Disseminating the intervention in a group setting rather than an individual setting alleviates some of these issues and appears not to be detrimental to patient outcomes, but often group programs cannot be billed to insurance, so the cost burden in placed on the patient or practitioners. If community centers can house the interventions and find trained interventionists, more patients would have access to the program, hopefully at a lower cost than through an outpatient clinic; the DPP is already spearheading this model around the country²⁰. Using new technologies, like HIPPA-approved online and telephone communications, smart phone applications, and smart scales, can also reduce the cost of overhead. In addition, the ideal program would also offer participants an opportunity to practice new skills, like cooking, exercising, and grocery shopping¹³. While HHL addresses these topics, the MGH Weight Center, like many weight management clinics, is not designed to accommodate cooking or physical activity currently. Further studies may explore incorporating more experiential classes, expanding to new class times and locations, adding a resting metabolic rate re-evaluation at the end of the class to observe resting metabolic rate (RMR) change with weight loss, incorporating meal replacement products, and/or using the HHL model in an online delivery system.

Abbreviation List

ACC

American College of Cardiology

ADA

American Diabetes Association

AHA

American Heart Association

ALT

alanine transaminase

AOM

anti-obesity medication

AST

aspartate transaminase

BMI

Body Mass Index

BW

body weight

DPP

Diabetes Prevention Program

DSE

Diabetes Support and Education

HbA1c

Hemoglobin A1c

HDL

high density lipoprotein

HHL

Healthy Habits for Life

ILI

Intensive Lifestyle Intervention

IRB

Institutional Review Board

LDL

low density lipoprotein

MetS

Metabolic Syndrome

MGH

Massachusetts General Hospital

NAFLD

Non-alcoholic fatty liver disease

RD

registered dietitian

RMR

resting metabolic rate

T2DM

Type 2 diabetes mellitus

TBWL

total body weight loss

TOS

The Obesity Society

WHO

World Health Organization