People whose weight fluctuated in the first six weeks of a new study lost less total weight over the next two years.
If you’re trying to slim down to a goal weight, dropping more pounds than usual on any given week may feel like a real triumph—even if you gain a little of it back, or don’t lose as much the following week. But new research suggests that people who shed pounds at a consistent pace ultimately lose more weight long-term than those whose losses fluctuate from week to week.
The study, published in the journal Obesity, focused on 183 overweight or obese volunteers who signed up for a year-long weight-loss program. The program used meal replacements and encouraged behavioral goals (like monitoring calorie intake and increasing physical activity), and participants attended weekly group meetings and weigh-ins.
The researchers were particularly interested in the first few weeks of the program, and wanted to see if they could identify any characteristics that would predict the participants’ ultimate weight-loss success or failure.
They found that, above all else, consistency was key. People who had higher weight variability in the first six and 12 weeks of the program lost less total weight over the program’s entire 12-month period. They’d also lost less overall weight at a 24-month check-in, a full year after the program ended.
“It could be that for people who tend to structure their eating very regularly, that may help them control their food intake and keep steady patterns—and that may be easier to maintain over the long-term,” says co-author Michael Lowe, Ph.D., professor of psychology at Drexel University. “Whereas people who take more drastic approaches to weight loss, or who have more arbitrary or impulsive behaviors, may experience bigger losses but also more re-gains.”
Surprisingly, the people who had the most weight fluctuations and the poorest outcomes over time were also the ones who, on average, reported at the start of the study that they were less likely to binge-eat, eat for emotional reasons, or be preoccupied with food.
Those correlations—the opposite of what the researchers expected to find—were small, and need to be replicated in future studies, says Lowe. “But it might mean that whatever weight variability does reflect, it’s apparently not something that we’re aware of or that we’re doing consciously,” he adds.
Lowe points out that the study could only find an association between weight fluctuation and poorer weight-loss performance over time—and he says it’s possible that the people whose weight yo-yoed during the first few weeks of the program had been dealing with similar ups and downs for long before the program started. But he does think that there’s some practical advice in his research for anyone who wants to lose weight and keep it off.
“Figure out a way you can cut back on calories, but do it in a way that isn’t too challenging—that you think you can do repeatedly over time,” he says. “It might be better to lose three-quarters of a pound week by week than to lose three pounds one week and then gain a pound and lose two, because whatever’s producing those herky-jerky changes is probably not sustainable.”