Study of Novel Approaches for Prevention (SNAP)
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|ClinicalTrials.gov Identifier: NCT01183689|
Recruitment Status : Active, not recruiting
First Posted : August 18, 2010
Results First Posted : May 7, 2018
Last Update Posted : February 25, 2019
The Study of Novel Approaches for Prevention (SNAP) is randomized trial designed to test whether behavioral interventions based on self-regulation can prevent weight gain in young adults (18-35 years; body mass index (BMI) 21-30 kg/m2). Two different self-regulation interventions for weight gain prevention will be compared in this trial; one intervention will focus on making small, consistent, changes in eating and exercise behavior to prevent weight gain or reverse weight gain if it occurs, whereas the other will emphasize larger changes in eating and exercise that occur periodically, with a goal of producing weight loss and thereby providing a buffer against anticipated weight gains. The primary aim of the trial is to test whether the magnitude of weight gain from baseline across an average three-year follow-up differs across the three groups, with the hypotheses that weight gain will be greater in the Control group than in either intervention and greater in the Small Changes than Large Changes group.
SNAP-E (Extension) will determine whether the effects of the intervention can be maintained over an additional 3 years (i.e. through a total of 6 years).
|Condition or disease||Intervention/treatment||Phase|
|Weight Gain||Behavioral: Small Behavior Changes Behavioral: Large Behavior Changes||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||599 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Double (Investigator, Outcomes Assessor)|
|Official Title:||Study of Novel Approaches for Prevention|
|Actual Study Start Date :||August 2010|
|Actual Primary Completion Date :||December 31, 2014|
|Estimated Study Completion Date :||May 2019|
No Intervention: Control Group
"Self-Guided Behavior Changes". This group will be used to determine average rate of weight gain over 3 years with little intervention. Participants randomized to this group will receive one face-to-face session that will provide general education of self-weighing and information about both the small and large changes approach. Participants will also be provided with quarterly newsletters describing study events and very limited information on health eating.
Experimental: Small behavior changes
Participants randomized to this group will be taught to self-weigh daily and report weights regularly. They will be reinforced for maintaining weight below randomization weight and taught that if weight exceeds randomization weight, they should reinstate small changes (e.g., modify diet by approximately 100 kcal, decrease portion sizes or change types of food, increase activity by 2000 steps/day).
Behavioral: Small Behavior Changes
The Self-Regulation Plus Small Behavior Changes Intervention will focus on making small changes in diet and physical activity on a daily basis to prevent weight gain.
Diet: The dietary approach used in this group is to identify small changes in what and how much participants eat each day. The general concept is that these are small, manageable changes that will produce small reductions in overall intake and can easily be made on a daily basis and maintained over time.
Exercise: At the start of the program, participants will be given a pedometer and asked to record their current or baseline number of steps. They will then be given the goal of increasing their daily steps by 2000 steps per day over this baseline level.
Other Name: Small Behavior Changes plus self-regulation
Experimental: Large behavior changes
Participants randomized to this group will be taught to self-weigh daily and report weights regularly. They will be reinforced for maintaining weight below randomization weight and taught that if weight exceeds randomization weight, they should reinstate large changes (e.g., modify diet to 1200-1500 or 1500-1800 kcal/day with < 30% fat, increase exercise to 250 minutes/week of moderate intensity activity).
Behavioral: Large Behavior Changes
The focus of this intervention group will be on periodically making large changes in diet and physical activity, with the goal of losing 5-10 pounds to buffer against the weight gain that often occurs during young adulthood.
Diet: Individuals with a BMI of 21-24.9 kg/m2 will be encouraged to lose 5 pounds; those with a BMI of 25-30 kg/m2 will be encouraged to lose 10 pounds.
Exercise: The Large Changes group will be instructed to gradually increase their minutes of physical activity until achieving 250 minutes per week (5 days/week with 50 minutes per day) using activities similar in intensity to brisk walking.
Other Name: Large Behavior Changes plus self-regulation
- Weight Changes From Baseline Over Follow-up. [ Time Frame: 3 years ]Mean weight change from baseline across an average planned follow-up of three years. These mean changes will be compared among the three arms of the trial.
- Weight Gain 1 Pound or More at Any Time Over Follow-up [ Time Frame: 3 years ]Average over time (average follow-up of 3 years) of the percent of participants within each arm of the trial who gain 1 pound or more at each visit. These percentages will be compared among the three arms generalized estimating equations. Note that weight changes in units of pounds were used to define this outcome so that it may be more clear to participants. Elsewhere in the protocol, weight is reported in kilograms. Percentages at each visit are the percent who gained 1 pound or more from baseline among all who were weighed at that visit. Participants were assigned values of 0 or 1 at each visit depending on their weight gain status.
- Mean Weight Changes [ Time Frame: 2 years ]Mean differences in weight changes among intervention groups at 24 months post-randomization
- Mean Changes in Systolic Blood Pressure [ Time Frame: Measured at 2 Years ]Compare changes in systolic blood pressure across the three intervention groups
- Mean Changes From Baseline in Diastolic Blood Pressure [ Time Frame: 2 years ]Change from baseline to 2 years in diastolic blood pressure
- Mean Changes From Baseline to 2 Years in Total Cholesterol [ Time Frame: 2 years ]Mean changes from baseline to 2 years in total cholesterol among participants with Year 2 measurements (mg/dl)
- Obesity [ Time Frame: 3 years ]Percentage of those participants whose body mass index at baseline was less than 30 kg/m2 who subsequently transitioned to a body mass index of 30 kg/m2 or more (i.e. met criteria for obesity) sometime during 3 years of follow-up (i.e. at least one visit). Percentages will be compared among the three arms of the trial and summarized with odds ratios Participants were assigned values of 0 or 1 at each exam depending on their obesity level. Inference is based on generalized estimating equations.
- Dietary Restraint: Mean Change From Baseline to 2 Years [ Time Frame: 2 years ]
The Eating Inventory (Stunkard, 1988) is a 51-item self-report instrument, was used to assess the subscale of dietary restraint (e.g., degree of conscious control exerted over eating behaviors; range from 0-21 with higher scores reflecting greater levels of restraint).
Reference: Stunkard, A. J. M., S. (1988). Eating Inventory Manual. New York: Psychological Corporation.
- Disinhibition [ Time Frame: Changes at 2 years ]
The Eating Inventory (TFEQ(Stunkard, 1988), a 51-item self-report instrument, was used to assess the subscale of disinhibition (e.g., susceptibility to loss of control over eating; range 0-16, with higher scores reflecting greater levels of disinhibition).
REF: Stunkard, A. J. M., S. (1988). Eating Inventory Manual. New York: Psychological Corporation.
- Flexible Dietary Control [ Time Frame: Changes from baseline to 2 years ]
Flexible control is characterized by a balanced approach to eating (e.g., taking smaller portions to control weight, engaging in healthy compensation) and is associated with better weight management outcomes (Westenhoefer, Stunkard, & Pudel, 1999). Scores range from 0 to 12 with higher scores reflecting greater levels of flexible control.
REF: Westenhoefer, J., Stunkard, A. J., & Pudel, V. (1999). Validation of the flexible and rigid control dimensions of dietary restraint. Int J Eat Disord, 26(1), 53-64.
- Rigid Dietary Control [ Time Frame: Changes from baseline to 2 years ]
Rigid control is characterized by an all-or-nothing inflexibility around dietary rules (e.g., strict calorie counting, with guilt following if calorie-dense foods are consumed) that is associated with poor weight outcomes and more binge eating (Westenhoefer, Stunkard, & Pudel, 1999). Scores range from 0 to 16 with higher scores reflecting greater rigid control.
REF: Stunkard, A. J. M., S. (1988). Eating Inventory Manual. New York: Psychological Corporation.
- General Health Index [ Time Frame: Changes from baseline to 2 years ]
The General Health Index, a one-item question from the CDC's Health-Related Quality of Life measure (Measuring Healthy Days, 2000) required participants to report whether in general their health is excellent (1), very good (2), good (3), fair (4), or poor (5). Lower scores denotes better outcomes.
Ref: Measuring Healthy Days. (2000). Atlanta, Georgia: Centers for Disease Control and Prevention
- Mean Changes in High Density Lipoprotein Cholesterol (HDL-C) [ Time Frame: 2 years ]Mean changes in HDL-C from baseline to year 2 in (mg/dl) for compared among the 3 arms using analysis of variance
- Mean Changes in Low Density Lipoprotein Cholesterol (LDL-C) [ Time Frame: 2 years ]Mean changes between baseline and 2 years in low density lipoprotein cholesterol: LDL-c (mg/dl)
- Mean Change in Fasting Glucose From Baseline to 2 Years [ Time Frame: 2 years ]Mean change in fasting glucose from baseline to 2 years in mg/dl for all participants with year 2 measures
- Mean Change in Fasting Insulin From Baseline to 2 Years [ Time Frame: 2 years ]Mean change in fasting insulin (uU/ml) from baseline to 2 years
- Depression Symptomatology [ Time Frame: 2 years ]Mean changes in the Center for Epidemiologic Studies Depression (CES-C) Scale. Reference: Turvey, C. L., Wallace, R. B., & Herzog, R. (1999). A revised CES-D measure of depressive symptoms and a DSM-based measure of major depressive episodes in the elderly. Int Psychogeriatr, 11(2), 139-148. 20 item questionnaire with a possible range of scores is zero to 60, and higher scores indicating the presence of more symptomatology.
- Insulin Resistance [ Time Frame: Change from baseline to 2 years ]We calculated homeostatic model assessment insulin resistance (HOMA-IR): fasting glucose in (mg/dl) * fasting insulin in (uU/mL).
- Total Energy Dietary Intake Per Day (Kcals) [ Time Frame: Changes from baseline to 2 years in kilocalories ]
Dietary intake was assessed using the 2005 Block Food Frequency Questionnaire (Block FFQ) at baseline and 2 years. This validated, quantitative 110-food item questionnaire is designed to assess relative intake of energy.
REF: Block G, Woods M, Potosky A, Clifford C. Validation of a self-administered diet history questionnaire using multiple diet records. J Clin Epidemiol 1990; 43:1327-1335.
- Change in Waist Circumference (cm) [ Time Frame: Change from baseline to 2 years ]Waist circumference will be measured using a Gulik tape measure and following a standardized protocol. Two measures of waist circumference will be taken; if the difference exceeds 1.0 cm, a third measure will be taken. Changes are measured from baseline to year 2.
- Self-weighing [ Time Frame: 2 years ]Number of days per week the participant reports weighing themselves. This is divided into two groups: 1) more than once per week and 2) no more than once per week
- 6 Year Weight Changes [ Time Frame: 6 years ]Changes from baseline to year 6 in body weight
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01183689
|United States, North Carolina|
|University of North Carolina|
|Chapel Hill, North Carolina, United States, 27559|
|United States, Rhode Island|
|The Miriam Hospital|
|Providence, Rhode Island, United States, 02903|
|Study Chair:||Rena Wing, PhD||The Miriam Hospital|
|Principal Investigator:||Judy Bahnson||Wake Forest University Health Sciences|
|Principal Investigator:||Wei Lang, PhD||Wake Forest University Health Sciences|
|Principal Investigator:||Mark A Espeland, PhD||Wake Forest University Health Sciences|
|Principal Investigator:||Deborah Tate, PhD||University of North Carolina, Chapel Hill|
|Principal Investigator:||Beth Lewis, MD||University of Alabama at Birmingham|