Troy Brown, RN
September 01, 2017
For people participating in a behavioral weight-loss program, those with weight variability during the first 6 to 12 weeks had worse weight-loss outcomes at 1 and 2 years than those who lost weight consistently in the early weeks, a study has found.
Emily H Feig, PhD, and Michael R Lowe, PhD, department of psychology, Drexel University, Philadelphia, Pennsylvania, report their findings online August 28 in Obesity.
"It seems that developing stable, repeatable behaviors related to food intake and weight loss early on in a weight-control program is really important for maintaining changes over the long term," Dr Feig said in a Drexel University news release.
The study included 183 adult participants in a yearlong behavioral weight-loss program with a baseline body mass index between 27 and 45 kg/m2. Program sessions occurred weekly for the first 6 months, biweekly during months 7 through 9, and monthly for the remainder of the year. Participants returned for follow-up at month 24.
The program was based on the LEARN Program for Weight Management textbook and used behavioral goals, including self-monitoring, calorie tracking, and increasing physical activity.
Participants who experienced higher weight variability during the first 6 and 12 weeks had less weight loss at 12 months (6-week, β = 0.18; P = .02; 12-week, β = 0.33; P < 0.01) and 24 months (6-week, β = 0.17; P = .03; 12-week, β = 0.15; P = .05). Results were similar after adjustment for covariates including percent weight change at 6 weeks, number of program sessions missed, gender, emotional eating, and preoccupation with food.
The association between weight variability and weight change at 6 months was stronger for men than women. "While weight variability did not predict weight change at the end of active treatment (6 months), when controlling for covariates, a gender-by-6-week weight variability interaction was significant, indicating that the relationship between 6-week weight variability and weight change at 6 months was stronger for men than for women," the researchers write.
Weight variability was higher among men than women after controlling for body mass index. However, women made up 81% of the sample; therefore, the authors urge caution in interpreting these results.
"The correlation between weight variability and future weight change does not necessarily indicate that weight variability causes weight gain. Research on dietary restraint supports the notion that strict dietary restriction, characterized as a 'dichotomous, rule-based, all-or-nothing approach to eating,' which may result in large short-term weight losses, is often followed by disinhibition and regain," the authors explain.
"Those with higher weight variability could be using stricter, rigid dieting practices, resulting in larger drops in weight. Rigid dieting could then spur periods of increased disinhibition and regain."
There are other possible explanations for the findings, the researchers say. Participants with higher variability could have a "stronger drive to eat," which would lead to greater energy intake and make restraint harder to maintain. Some people may have physiological differences that make them lose weight less consistently than others and less likely to see immediate results even when they follow recommendations consistently. That could cause them to feel disheartened and lose motivation, leading to weight gain.
Because the results were similar when the researchers looked at weight variability at 6 weeks and 12 weeks, they suggest that examining weight variability at 6 weeks is likely sufficient to predict weight-loss success.
"Future research should examine replicability of these findings and should clarify whether measuring weight variability adds to interventionists' ability to identify individuals unlikely to achieve meaningful and sustainable weight loss. If found to be reliable and useful, weight variability early in treatment may be cause for supplemental intervention," the researchers explain.
"Future research should also examine the behavioral and/or metabolic basis for weight variability and whether increasing the stability of week-to-week weight losses improves long-term outcomes. If this is the case, behavioral interventions may benefit from a stronger focus on consistent weekly weight losses," they conclude.
Dr Lowe reports receiving compensation from funded users of the Power of Food Scale. Dr Feig has disclosed no relevant financial relationships.