Study of Novel Approaches for Prevention
Condition: Weight Gain
MeSH terms: Weight Gain
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): Small Behavior Changes; Large Behavior Changes
Intervention type(s): Behavioral; Behavioral
Intervention description(s): 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.; 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 intervention name(s): Small Behavior Changes plus self-regulation; Large Behavior Changes plus self-regulation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Prevention