UF study identifies week-to-week predictors of weight loss, regain

The holiday season is full of delicious minefields that can derail a weight-loss or weight-maintenance plan: high-calorie treats, limited time for exercise and stress.

In a new study published in the journal Health Psychology, University of Florida researchers examined how people’s thoughts, feelings and behaviors during one week can predict weight change the following week. Knowing what factors play a role in week-to-week weight change may help people manage their weight during challenging periods, such as the holidays, said lead author Kathryn Ross, Ph.D., an assistant professor in the department of clinical and health psychology in the UF College of Public Health and Health Professions, part of UF Health.

“Based on our findings, weighing yourself regularly, tracking your calories and engaging in physical activity might be particularly important strategies for preventing extra weight gain during the holidays,” Ross said. “Most people tend to experience some weight gain around the winter holiday season, but people who continue to self-monitor their calorie intake and weight are less likely to gain weight during this time. It may be that the act of writing everything down helps you say no to extra treats, or it may be that keeping track of what you eat and drink can help you make adjustments.”

In addition to self-monitoring, the researchers found people who were most successful at losing weight made food choices consistent with their weight-loss goals and placed greater importance on staying on track with goals. They also reported more positive mood, less boredom with weight-control efforts, less hunger and less temptation to eat foods “not on plan.”

Conversely, people who regained weight were less likely to self-monitor, engaged in less physical activity and had a less-positive mood, more stress and greater temptation to skip planned physical activity, and felt that staying on track took more effort.

The UF study — funded by the National Institute of Diabetes and Digestive and Kidney Diseases — is the first to look at behavioral factors related to weight on a weekly basis. Previous studies have asked participants questions about mood and thoughts at baseline, at the conclusion of a weight-loss intervention and/or months later. But valuable information may be missed with that approach, Ross said.

“A limitation to results based on retrospective recall is that our memory of past thoughts, feelings and behaviors isn’t that great,” she said. “Research has shown that, rather than our memories being ‘snapshots’ in time, they’re more like reconstructions based on our current opinions and behaviors and thoughts of how we think we would have previously thought, felt or behaved.”

The study involved 75 participants who took part in an internet-based program for employees of a Rhode Island health care corporation. After an initial weight-loss intervention, participants were tracked for nine months. They used a smart scale daily that transmitted their weight data directly to researchers via a cellular network. Participants logged into a study website once a week to submit self-monitoring data on calorie intake, exercise and weight, and to answer questions about their mood, stress, hunger and more.

On the basis of the data gathered during the study, Ross and her team have developed a predictive weight-gain algorithm they are using in a new $3 million study funded by the NIDDK. Following a weight-loss intervention, participants will be randomly assigned to one of two groups that will be followed for two years using a smartphone-based weight-maintenance program. One group will receive the current standard for extended care: monthly follow-ups on a fixed schedule from an interventionist to discuss barriers to weight maintenance and problem-solving strategies. In the other group, if the smartphone app detects a participant may be in a high-risk period for weight gain, an interventionist will contact the participant to offer support.

The goal is to gain an even better understanding of how health care providers can help individuals navigate the challenges of weight loss and weight-loss maintenance.

“Current weight-loss interventions don’t work the same for everybody, and that variability is even greater during the weight-loss maintenance period,” Ross said. “The one-size-fits-all approach isn’t going to be our answer forever. Our hope is that we will start to build the foundational data we need to develop personalized interventions for weight control.”