Study of Novel Approaches for Prevention

Study Overview
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Brief Summary
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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).

Detailed Description
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Young adults, aged 20-35 years, experience the greatest rate of weight gain, averaging 1-2 lbs/yr. Over time, this weight gain is associated with a worsening in cardiovascular disease risk factors and an increase in the prevalence of metabolic syndrome. Given the difficulties in producing sustained weight loss later in life, preventing weight gain from occurring during this critical period is key to curbing the obesity epidemic. The Study of Novel Approaches for Prevention (SNAP) is a 2-center 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). Approximately 600 participants will be recruited over two years and randomly assigned to a control condition (N=200), self-regulation with small changes (N=200) or self-regulation with large changes (N=200). The Small Changes group will be taught to make small, consistent, changes in eating and exercise behavior to prevent weight gain or reverse weight gain if it occurs whereas the Large Changes group will emphasize periodic, larger changes in eating and exercise, with a goal of producing weight loss and thereby providing a buffer against anticipated weight gain. The primary aim of the trial is to test whether the magnitude of weight gain from baseline across an average planned follow-up of three years differs across the three groups, with a priori 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. Secondary aims are to compare the three groups on a) the proportion of participants in the three groups who gain less than 1 pound over the planned follow-up, b) the mean difference in weight gain from baseline to 24-month follow-up, c) the changes in behaviors and psychosocial measures (diet, physical activity, dietary restraint, frequency of self-weighing,depression, and occurrence of abnormal eating behaviors), and d) the changes in cardiovascular disease risk factors (blood pressure, lipids, insulin sensitivity, and waist circumference). The trial will also examine the association among changes in behaviors, weight, and cardiovascular disease risk factors and examine variables that may moderate the effects of the intervention (including gender, ethnicity, initial BMI, age) and potential mediators of the effects of the intervention (including changes in diet, activity, and self-regulatory behaviors). SNAP is member of the Early Adult Reduction in Weight Through Lifestyle Interventions (EARLY) consortium of clinical trials funded by the National Heart, Lung, and Blood Institute.

Official Title
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Study of Novel Approaches for Prevention

Conditions
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Weight Gain

Intervention / Treatment
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* Behavioral: Small Behavior Changes
* Behavioral: Large Behavior Changes


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. BMI of 21 - 30 kg/m2 Exclusion Criteria: Untreated hypertension, hyperlipidemia, or type 2 diabetes, unless permission is provided by their health care provider. Heart disease, heart problems or report being prescribed drugs for blood pressure or a major heart condition, unless permission is provided by their health care provider. Type 1 diabetes or treatment of type 2 diabetes with insulin or oral medication that may cause hypoglycemia. Health problems which may influence the ability to walk for physical activity (e.g. lower limb amputation) or other reasons why a person should not do physical activity, unless permission is provided from their health care provider. Health problems that may be associated with unintentional weight change or affect the safety of a weight loss program, including report of a heart attack or stroke, chest pain during periods of activity or rest, loss of consciousness, active tuberculosis, HIV, chronic hepatitis B or C, inflammatory bowel disease requiring treatment within the past year, thyroid disease, renal disease, liver disease, hospitalization for asthma in the past year, or cancer within the past 5 years (except for non-melanoma skin cancers or early stage cervical cancer) or chronic use of steroid medication. Report of a past diagnosis of or treatment for a Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision (DSM-IV-TR) eating disorder (anorexia nervosa or bulimia nervosa) or meet criteria for anorexia or bulimia nervosa during screening for this trial Report of a past diagnosis of or current symptoms of alcohol or substance dependence. Currently pregnant, pregnant within the past 6 months, or planning to become pregnant within the next 6 months. History of schizophrenia, manic depression, or bipolar disorder. Hospitalization for depression or other psychiatric disorder within the past 12 months. Having lost and maintained a weight loss of 10 pounds or more within the past 6 months or are currently participating in a weight loss program, trying to gain weight, using steroids for muscle mass or weight gain, taking weight loss medication, or have had surgery for weight loss. Participation in another weight loss or physical activity study that would interfere with this study. Another member of the household (or roommate) is a participant or staff member on this trial. Reason to suspect that the participant would not adhere to the study intervention or assessment schedule (i.e., can't come to group on a regular basis; will be away for more than two weeks during initial intervention phase or planning to move from the area within next year). Not able to speak and understand English. Residence or place of work further than 30 miles from the intervention site. Perceived inability to attend the 2 year data collection visit. Does not have Internet access on a regular basis.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control Group<br>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<br>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<br>* 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.<br>* Other names: Small Behavior Changes plus self-regulation;|
| Experimental: Large behavior changes<br>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<br>* 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.<br>* Other names: Large Behavior Changes plus self-regulation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight Changes From Baseline Over Follow-up. | 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. | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight Gain 1 Pound or More at Any Time Over Follow-up | 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. | 3 years | 
| Mean Weight Changes | Mean differences in weight changes among intervention groups at 24 months post-randomization | 2 years | 
| Mean Changes in Systolic Blood Pressure | Compare changes in systolic blood pressure across the three intervention groups | Measured at 2 Years | 
| Mean Changes From Baseline in Diastolic Blood Pressure | Change from baseline to 2 years in diastolic blood pressure | 2 years | 
| Mean Changes From Baseline to 2 Years in Total Cholesterol | Mean changes from baseline to 2 years in total cholesterol among participants with Year 2 measurements (mg/dl) | 2 years | 
| Obesity | 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. | 3 years | 
| Dietary Restraint: Mean Change From Baseline to 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. | 2 years | 
| Disinhibition | 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. | Changes at 2 years | 
| Flexible Dietary Control | 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. | Changes from baseline to 2 years | 
| Rigid Dietary Control | 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. | Changes from baseline to 2 years | 
| General Health Index | 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 | Changes from baseline to 2 years | 
| Mean Changes in High Density Lipoprotein Cholesterol (HDL-C) | Mean changes in HDL-C from baseline to year 2 in (mg/dl) for compared among the 3 arms using analysis of variance | 2 years | 
| Mean Changes in Low Density Lipoprotein Cholesterol (LDL-C) | Mean changes between baseline and 2 years in low density lipoprotein cholesterol: LDL-c (mg/dl) | 2 years | 
| Mean Change in Fasting Glucose From Baseline to 2 Years | Mean change in fasting glucose from baseline to 2 years in mg/dl for all participants with year 2 measures | 2 years | 
| Mean Change in Fasting Insulin From Baseline to 2 Years | Mean change in fasting insulin (uU/ml) from baseline to 2 years | 2 years | 
| Depression Symptomatology | 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. | 2 years | 
| Insulin Resistance | We calculated homeostatic model assessment insulin resistance (HOMA-IR): fasting glucose in (mg/dl) * fasting insulin in (uU/mL). | Change from baseline to 2 years | 
| Total Energy Dietary Intake Per Day (Kcals) | 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. | Changes from baseline to 2 years in kilocalories | 
| Change in Waist Circumference (cm) | 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. | Change from baseline to 2 years | 
| Self-weighing | 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 | 2 years |