The interventions have been described in detail.22 (link) The Control group attended one face-to-face meeting where they were introduced to the issue of weight gain, the concept of self-regulation, and an overview of both Small and Large Change approaches to potentially prevent weight gain.
Small and Large Changes interventions both began with 10 face-to-face group meetings over 4 months. This treatment length was selected to be sufficient to enable the 5 or 10 pound weight loss, but easily disseminated. Subsequently, the interventions were delivered primarily online. Each year, participants were invited to join two 4-week online refresher campaigns reinforcing the behaviors taught during the initial program. All participants received identical quarterly newsletters and personalized feedback reports on their assessment data, including the Control group.
The interventions were both framed in a self-regulation model that forms the basis for several self-control theories 25 –28 and has been applied to diabetes 29 (link) and obesity 15 (link) and was used in a pilot study for this trial.30 (link) Self-regulation is based on a negative feedback loop, in which there is a goal, error detector and controlling responses. In SNAP, the goal was to not exceed baseline weight, the error detector was the scale and daily self-weighing, and the controlling responses involved changes in diet and exercise consistent with the Small or Large Change approach. To encourage self-regulation, participants were instructed to weigh themselves daily and submit their weight via the study website, text message or email. They received monthly email feedback on their weight, which was based on a color-coded system15 (link),22 (link) and either reinforced their success, encouraged problem-solving, or recommended additional strategies to help reverse weight gain. Participants who gained above baseline were invited to contact a study interventionist for problem solving assistance via email, phone or face-to-face, but very few requested this assistance.
The specific recommendations related to diet and activity differed for Small Changes vs Large Changes. Participants in Small Changes were taught to make daily small changes (approximately 100 kcal/day) in both diet (e.g. select lower calorie coffee drinks, reduce portion sizes) and physical activity (e.g. park farther from store, use stairs). Participants were given pedometers and instructed to add 2000 steps per day (equivalent to 1 mile) above baseline. If participants in Small Changes experienced weight gains above baseline, they were encouraged to make additional daily small changes.
Large Changes focused on losing weight (5 lbs if normal weight; 10 lbs if overweight) during the initial four-month program to create a buffer against subsequent weight gain. To achieve this, participants were prescribed a calorie goal based on a 500 to 1000 kcal deficit from baseline to use during the initial 8 weeks. They were also encouraged to gradually increase moderate intensity physical activity to a goal of 250 minutes/week, the level recommended for weight loss maintenance,31 (link) and to maintain this over time. If weight exceeded baseline, they were to return to their calorie goal and confirm that they were achieving the activity goal.
Small and Large Changes interventions both began with 10 face-to-face group meetings over 4 months. This treatment length was selected to be sufficient to enable the 5 or 10 pound weight loss, but easily disseminated. Subsequently, the interventions were delivered primarily online. Each year, participants were invited to join two 4-week online refresher campaigns reinforcing the behaviors taught during the initial program. All participants received identical quarterly newsletters and personalized feedback reports on their assessment data, including the Control group.
The interventions were both framed in a self-regulation model that forms the basis for several self-control theories 25 –28 and has been applied to diabetes 29 (link) and obesity 15 (link) and was used in a pilot study for this trial.30 (link) Self-regulation is based on a negative feedback loop, in which there is a goal, error detector and controlling responses. In SNAP, the goal was to not exceed baseline weight, the error detector was the scale and daily self-weighing, and the controlling responses involved changes in diet and exercise consistent with the Small or Large Change approach. To encourage self-regulation, participants were instructed to weigh themselves daily and submit their weight via the study website, text message or email. They received monthly email feedback on their weight, which was based on a color-coded system15 (link),22 (link) and either reinforced their success, encouraged problem-solving, or recommended additional strategies to help reverse weight gain. Participants who gained above baseline were invited to contact a study interventionist for problem solving assistance via email, phone or face-to-face, but very few requested this assistance.
The specific recommendations related to diet and activity differed for Small Changes vs Large Changes. Participants in Small Changes were taught to make daily small changes (approximately 100 kcal/day) in both diet (e.g. select lower calorie coffee drinks, reduce portion sizes) and physical activity (e.g. park farther from store, use stairs). Participants were given pedometers and instructed to add 2000 steps per day (equivalent to 1 mile) above baseline. If participants in Small Changes experienced weight gains above baseline, they were encouraged to make additional daily small changes.
Large Changes focused on losing weight (5 lbs if normal weight; 10 lbs if overweight) during the initial four-month program to create a buffer against subsequent weight gain. To achieve this, participants were prescribed a calorie goal based on a 500 to 1000 kcal deficit from baseline to use during the initial 8 weeks. They were also encouraged to gradually increase moderate intensity physical activity to a goal of 250 minutes/week, the level recommended for weight loss maintenance,31 (link) and to maintain this over time. If weight exceeded baseline, they were to return to their calorie goal and confirm that they were achieving the activity goal.
