Randomized Controlled Trial

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POSITIVE: See Quality Criteria Checklist below.

To implement and evaluate the influence of a comprehensive nutrition and lifestyle education intervention (six post-operative education sessions that incorporated behavior modification strategies into nutrition counseling) in comparison to a non-comprehensive minimal approach (printed guidelines on healthy eating and physical activity recommendations) on weight loss and physical activity in Hispanic American adults six to 12 months following Laparoscopic Roux-en-Y gastric bypass (RYGB).

• Hispanic Americans with morbid obesity
• Recently had (six months ±6 weeks before recruitment) undergone laparoscopic RYGB surgery for reversing morbid obesity at the Palmetto General Hospital in Hialeah, FL
• Must have been aged 18 years and older with English or Spanish proficiency
• To have participants relatively homogeneous regarding bariatric diet knowledge, nutritional status and compliance, only those who attended at least five nutrition-counseling sessions with a registered dietitian (RD) were included.

• Non-ambulatory
• Pregnancy
• Anatomical problems following surgery that required re-operation
• Medical problems such as kidney, adrenal or heart disease.

Recruitment

• From the Laparoscopic Institute of South Florida
• Primary recruitment: Telephone calls and placing flyers in the waiting room
• Secondary recruitment: The investigator, who was not involved in the patients’ usual care, extracted pre-operative information from patients’ records and contacted potential subjects inviting them to participate in this study
• Potential participants were fully informed regarding the purpose of the study, frequency of assessments, intervention schedules, expectations and extent of their participation
• Participants were not monetarily compensated for their time or transportation expenses
• On average, 18 participants were enrolled each month.

Design

Prospective, randomized controlled trial.

Intervention

• Immediately following the first assessment meeting with the investigator, participants were randomized into:
  • Comprehensive intervention group
  • Non-comprehensive (comparison) group.
• Standard of care at the bariatric center:
  • Pre-surgical medical, nutrition and psychological evaluation
  • During first post-operative year:
    • Patients meet with the surgeon at two and six weeks and then every three months
    • Patients met with the RDs monthly for the first six months and every six months thereafter. The dietary treatment sought to facilitate weight loss by reducing the risk of nutritional deficiencies.
• Study phases:
  • Assessment meetings with the investigator at six and 12 months following surgery (initial and final assessment, respectively) and an intervention
    • Initial (six-month) assessment with surgeon for monitoring nutritional deficiencies and co-morbidities (e.g., diabetes, hypertension and dyslipidemia) by laboratory tests 
    • All participants were reassessed at 12 months following surgery
    • Assessments included:
      • Self-reported forms on sociodemographic and medical information 
      • Patients’ medical records were also used to obtain pre-surgery measurements and to corroborate participants’ self-reported forms
      • Patient body weight was measured by a digital scale.

Comprehensive Intervention Group

• Received a total of six nutrition and lifestyle education and behavioral–motivational sessions in groups of up to 12 participants in Spanish or English according to the participant’s language preference
• Sessions were conducted every other week by an RD starting at seven months following surgery
• Each session took place at the Laparoscopic Institute of South Florida and lasted approximately 90 minutes
• Sessions were presented in lecture format with PowerPoint slides
• Participants were able to ask questions during the presentation and group discussion was encouraged at the end of each session
• Participants had the opportunity to complete any missed session before the final assessment and were allowed to receive printed materials for one, and only one, missed session
• The purpose of the intervention was the promotion of dietary recommendations reinforced by practical behavior-modification strategies for dealing with emotional difficulties encountered in the pursuit of healthy lifestyles
• All sessions stressed the need for adherence to lifelong supplementation with vitamins and minerals and the importance of physical activity in the post-operative bariatric life, along with a healthy diet
• Before and after completion of each education session, participants were asked to complete a brief pre-session and post-session quiz to evaluate the knowledge acquired.
• Intervention Session One:
  • Covered the daily meal planning guide and the maintenance diet
  • Recommendations for identifying and avoiding unhealthful foods
  • Tips to promote proper nutrition by controlling portion size
  • Establishing new routine eating habits
  • Using an exchange list for weight management
  • Session was based on the Dietary Guidelines for Americans 
  • Daily energy intake was limited to 1,000kcal to 1,400kcal
  • Minimum daily protein intake was 60g to 70g to preserve lean tissue and prevent nutritional deficiencies
  • Session emphasized information about the characteristics of typical Hispanic diets and the dietary changes that accompany the process of acculturation.
• Intervention Session Two:
  • Designed to help sedentary individuals start a consistent exercise program
  • Helped recognize the reasons why physical activity is important for keeping weight off after bariatric surgery.
• Intervention Sessions Three to Six:
  • Emotional support interventions
  • Behavior change strategies
  • Stress relief without food
  • Self-motivation
  • Relapse prevention
  • Increasing self-esteem
  • Overcoming obstacles to establish a consistent exercise program
  • Recognizing binge eating problems
  • Other motivational strategies.
• After each education session, participants in the comprehensive intervention group were sent compliance reminders by e-mail and telephone calls
• Reminders encouraged participants to stick to the bariatric diet and self-monitor their physical activity and dietary intake.

Non-comprehensive (Comparison) Group

• Did not receive the comprehensive education sessions
• Were provided brief printed guidelines for healthy eating and physical activity at the first assessment
• Guidelines consisted of three pages of information and tips on nutrition, foods and beverages to avoid and how to make physical activity a habit
• All the topics overlapped information provided in the comprehensive intervention
• This group did not receive behavior modification strategies or have frequent contact with the investigator by telephone calls, e-mail messages and reminder messages
• All participants were free to opt for additional counseling by an RD, psychologist or other professionals:
  • 45 participants (31.3%) opted for additional counseling by an RD
  • 15 participants (10.4%) opted for additional counseling by a psychologist
  • 88 participants (61.1%) visited a primary care physician or another professional.

Statistical Analysis

• Sample size was calculated using PASS software for Windows two-sample T-test power analysis for clinical studies
  • Assuming a minimal relevant difference in excess weight loss between the two treatment groups of 5%, a sample of 130 individuals was calculated as necessary to provide the study with 80% power to detect a difference of this magnitude (P<0.05)
  • A dropout rate of 10% was estimated; thus, a sample of 144 individuals (intervention group N
    =72, comparison group N
    =72) was recruited.
• Statistical analysis was performed using PASW for Windows (SPSS version 18.0, 2010, SPSS Inc, Chicago, IL):
  • All tests were two-sided with statistical significance set at P<0.05
  • Descriptive statistics (means±standard deviations or percentages) were used to characterize the population
  • Analyses of differences between groups for demographic and anthropometric variables were performed using independent samples T-tests for continuous variables and X² tests for categorical variables
  • Changes in weight measures, physical activity time and energy expenditure and nutrient intakes were compared using paired-samples T-tests within each group and independent samples T-tests between groups
  • Intent-to-treat principle was applied for statistical analyses
  • The effectiveness of the comprehensive nutrition and lifestyle education intervention was assessed by differences in mean percent excess weight loss between groups from six to 12 months following surgery
  • Mann-Whitney analysis was used to assess the differences within and between groups in length and intensity of exercise.

Timing of Measurements

• Study was conducted between November 2008 and April 2010
• Outcomes were determined at the initial and final assessment points, at six and 12 months, respectively, after surgery.

Dependent Variables

• Excess weight loss: Body weight measured by a digital scale
• Physical activity changes over time: Assessed via questionnaire (Short Questionnaire to Assess Health Enhancing Physical Activity).

Independent Variables

• Group assignment:
  • Comprehensive intervention
  • Comparison group.
• Nutrition data collected by an RD: 
  • The 24-hour dietary recalls were completed at each of the assessment points
  • Nutrient intake was estimated using the Diet Analysis Plus (version 9.0, 2008, ESHA Research, Salem, OR)
  • To limit under-reporting of food intake, the U.S. Department of Agriculture five-step multiple path method was applied, inducing additional recall of the most often forgotten foods (i.e., sweets, snacks, cheeses, breads and beverages), emphasizing the amount of food eaten and the time and settings at which the food was eaten.

Control Variables

All surgical procedures were performed by the same surgeon using identical surgical techniques.

Initial N

N=144.

Attrition (Final N)

• Assigned to comprehensive intervention: N=72
  • Only N=62 received the intervention
  • Did not receive allocated intervention (N=10):
    • Three family issues
    • Two transportation problem
    • Five other reasons.
  • Lost to follow-up (6.9%; N=5):
    • Three lost contact
    • Two moved.
  • Analyzed: N=72 Intention to treat analysis.
• Assigned to comparison group: N=72:
  • All N=72 received the non-comprehensive guidelines
  • Lost to follow-up (8.3%; N=6):
    • Six lost contact.
  • Analyzed: N=72 Intention-to-treat analysis.
     

Age

	Total (N=144)	Comprehensive (N=72)	Comparison (N=72)
	Mean ± Standard Deviation
Age (year)	44.5±13.5	44.2±12.6	44.8±14.4

Ethnicity

Hispanic Americans (the sample represented primarily Cuban-born bi-lingual women).

Other Relevant Demographics

	Total (N=144)	Comprehensive (N=72)	Comparison (N=72)	P-Value
	Mean ± Standard Deviation
Education (year)	13.7±2.7	14.0±2.8	13.4±2.6	0.200
Children (number)	1.6±1.3	1.8±1.4	0.4±1.3	0.136
	N (Percent)
Sex				0.371
Female	120 (83.3)	62 (86.1)	58 (80.6)
Male	24 (16.7)	10 (13.9)	14 (19.4)
Marital status				0.706
Married	66 (45.8)	34 (47.2)	32 (44.4)
Single	38 (26.4)	21 (29.2)	17 (23.6)
Divorced	35 (24.3)	15 (20.8)	20 (27.8)
Widowed	5 (3.5)	2 (2.8)	3 (4.2)
Nationality				0.257
Cuba	71 (49.3)	38 (52.8)	33 (45.8)
United States	38 (26.4)	21 (29.2)	17 (23.6)
Puerto Rico	20 (13.9)	6 (8.3)	14 (19.4)
Other	15 (10.4)	7 (9.7)	8 (11.1)
Language spoken				0.413
English and Spanish	75 (52.1)	39 (54.2)	36 (50.0)
Spanish	57 (39.6)	25 (34.7)	32 (44.4)
English	12 (8.3)	7 (7.9)	5 (6.9)
Occupation				0.053
Office administrator	40 (27.8)	13 (18.1)	27 (37.5)
Professional	26 (18.1)	18 (25.0)	8 (11.1)
Housewife	33 (22.9)	14 (19.4)	19 (26.4)
Student	14 (9.7)	8 (11.1)	6 (8.3)
Educator	11 (7.6)	6 (8.3)	5 (6.9)
Others	20 (13.9)	13 (18.1)	7 (9.7)
Employment				0.149
Employed	82 (56.9)	46 (63.9)	36 (50.0)
Unemployed	34 (23.6)	16 (22.2)	18 (25.0)
Disabled	21 (14.6)	9 (12.5)	12 (16.7)
Retired	7 (4.9)	1 (1.4)	6 (8.3)
Insurance				0.084
Private	50 (34.7)	25 (34.7)	25 (34.7)
Uninsured self-paid	43 (29.9)	25 (34.7)	18 (25.0)
Medicaid	36 (25.0)	19 (26.4)	17 (23.6)
Medicare	15 (10.4)	3 (4.2)	12 (16.7)
Smoking Habit				0.670
Never smoked	91 (63.2)	47 (65.3)	44 (61.1)
Former smoker	29 (20.1)	15 (20.8)	14 (19.4)
Current smoker	24 (16.7)	10 (13.9)	14 (19.4)

P-values are two-sided for the comparison between comprehensive and comparison groups.

Anthropometrics

	Comprehensive (N=72)	Comparison (N=72)
Weight (kg)
Pre-operative	131.01±28.01	136.47±35.39
Body mass index
Pre-operative	48.98±8.48	36.51±7.03

Location

The Laparoscopic Institute of South Florida (all participants had recent surgery at the Palmetto General Hospital in Hialeah, FL).

Key Findings

Comparison of Anthropometrics
	Within Groups		Between Groups
	Comprehensive (N=72)	Comparison (N=72)	Comprehensive (N=72)	Comparison (N=72)	P-value
	Mean ± Standard Deviation
Weight (kg)			17.33±11.74	10.03±9.43	<0.001
Pre-operative	131.01±28.01	136.47±35.39
Six months	94.57±21.19	100.32±24.89
12 months	77.24±19.21	90.29±21.93
Body mass index		49.54±9.65	6.48±4.37	3.63±3.41	<0.001
Pre-operative	48.98±8.48	36.51±7.03
Six months	35.37±6.83	32.89±6.18
12 months	28.88±6.49
Excess weight loss (kg)			17.33±11.74	10.03±9.43	<0.001
Six months	36.43±9.91	35.97±13.94
12 months	53.76±15.35	46.00±18.87
Excess weight loss (percent)			25.04±14.31	13.08±11.28	<0.001
Six months	54.56±12.90	50.68±12.89
12 months	79.60±15.48	63.76±14.24

 

Comparison of Physical Activity
	Within Groups		Between Groups
	Comprehensive (N=67)	Comparison (N=66)	Comprehensive (N=67)	Comparison (N=66)	P-value
Frequency (percent)			5 (7.0)	-4 (6.0)	0.131
Six months	50 (74.6)	48 (72.7)
12 months	55 (82.1)	44 (66.7)
P-value	0.302	0.503
Intensity (MET-h)			8.85±14.9	1.35±12.5	0.002
Six months	11.83± 11.3	10.98±10.2
12 months	20.68±18.0	12.33±13.6
P-value	<0.001	0.386
Frequency (days per week)			0.66±2.7	-0.02±2.8	0.159
Six months	3.22±2.4	3.18±2.3
12 months	3.88±2.2	3.17±2.7
P-value	0.052	0.965
Time, minutes per week			13.66±46.7	-3.56±38.9	0.023
Six months	45.97±37.0	42.88±34.1
12 months	59.63±48.1	39.32±33.7
P-value	0.019	0.460

Other Findings

• Study participants:
  • There was a 57% response rate to in-person recruitment and 7.64% attrition rate at one year
  • Of 72 participants, 27 were randomly assigned to the comprehensive intervention group attended the entire program (37.5%)
  • Ten individuals attended five sessions (13.9%) and the rest attended four (9.7%), three (9.7%), two (8.3%) and one session (6.9%), respectively
  • The overall attendance rate to the comprehensive educational program was 64.4%
  • The median number of session attended was three
  • The first session on nutrition was the session with the highest attendance (76.4%)
  • The second session, which discussed the importance of physical activity in the post-operative bariatric life, had an attendance rate of 66.7%
  • The total attrition rate during the study was 13.9%.
• Anthropometric outcomes:
  • Patients had a mean pre-operative excess body weight of 72.20± 27.81kg
  • Overall, participants lost an average of 52.62±12.99% of their excess body weight at six months
  • There were no significant differences in anthropometric characteristics between intervention and comparison group participants before surgery (pre-operative) and at six months after surgery (baseline assessment point)
  • Comprehensive group experienced significantly greater excess weight loss (25% vs. 13%; P<0.001) and significantly greater BMI reduction (6.48±4.37 vs. 3.63±3.41; P<0.001) than those in the comparison group who received non-comprehensive minimal approach (i.e., printed guidelines for healthy eating and physical activity recommendations)
  • At one year following surgery, comprehensive group participants lost 80% of their pre-operative excess weight, whereas comparison group participants lost 64% of their pre-operative excess weight (P<0.001).
• Physical activity outcomes:
  • Six months post-surgery, approximately 74% of participants reported doing some type of physical activity
  • At one year, approximately 82% and 67% of the intervention and comparison group participants respectively stated that they regularly exercise
  • Walking was reported as the most frequent physical activity over time
  • Within groups, intervention group participants significantly increased their mean time (P=
    0.019) and intensity of exercise (P<0.001) from six months to 12 months after surgery
  • In contrast, comparison group participants did not significantly change their activity behavior during the study period (P>0.05)
  • Between groups, intervention group participants were significantly more involved in physical activity (+14 minutes per week vs. -4 minutes per week; P<0.001) than comparison group participants.
• Dietary intake outcomes:
  • Between six and 12 months following surgery, mean total daily energy intake in both groups was slightly below the recommended guidelines for gastric bypass surgery, which is in the range of 1,000kcal to 1,400kcal for weight maintenance
  • Within both groups, the mean daily intake of protein was in the low range of the recommended for patients who have received gastric bypass, which is 60g to 105g based on a 1,000kcal to 1,400kcal diet
  • No significant differences in daily energy intake and number of meals between groups
  • Mean intake of protein in the comparison group was significantly lower than that of the intervention group (P=
    0.02).

• The comprehensive educational approach, which incorporated behavior change and motivation strategies into nutrition counseling, significantly increased weight loss and physical activity between six and 12 months following surgery
• Further research studies should be performed in ethnically diverse samples to identify relevant socio-cultural parameters that may be associated with, or promote, a positive response to comprehensive nutrition and lifestyle education interventions following bariatric surgery.

Other:

not described

• Funding source was not described
• Although an attention-intervention effect might have occurred during the semi-annual data collection visits, the randomization should have reduced or eliminated it (Note: The paper does not detail how the randomization was done)
• The nature of this intervention precluded the blinding of either participants or investigators, which might contribute to a placebo effect.