Baseline characteristics associated with different BMI trajectories in weight loss trials: a case for better targeting of interventions

Abstract

Background/Objectives: Dietary weight loss interventions have heterogeneous outcomes in long-term studies, with many participants regaining part or all of the lost weight. Growth mixture modelling is a novel analytic approach that can be used to identify different trajectories of weight change during a trial rather than focussing on the total amount of weight lost. Subjects/Methods: Data were pooled from two 12-month dietary weight loss studies where no significant difference was detected between the treatment and control arms, thus allowing analysis independent of treatment. The data set included 231 subjects (74.5% female), with a mean weight loss of 6.40 kg (4.96). Growth mixture models were used to identify participants with similar trajectories of change in body mass index (BMI). Results: Three subgroups were identified. A rapid and continuing BMI loss over the study period (rapid, n=53), a rapid initial weight loss in the first 3 months with a slowing rate over the remaining 9 months (maintainers, n=146) and those with an initial loss trajectory, which slowed and began to increase at 9 months (recidivists, n=53). Age (s.d.) and BMI (s.d.) were significantly different between the three groups (rapid 53 years (7), 28.99 kg/m2 (3.30); maintainers 47 years (9), 30.90 kg/m2 (2.95); recidivists 44 years (7), 34.84 kg/m2 (1.92), both P<0.001). Conclusions: Older subjects with lower BMIs were more likely to have a rapid and continuing weight loss in a 1-year dietary-based weight loss intervention. Different interventional approaches may be necessary for different ages and baseline BMIs and stratification prior to randomisation may be necessary to prevent confounding in weight loss trials.

A Randomized Controlled Trial of Dapagliflozin Plus Once-Weekly Exenatide Versus Placebo in Individuals with Obesity and Without Diabetes: Metabolic Effects and Markers Associated with Bodyweight Loss

“…However, more DAPA + ExQW-treated participants with higher baseline bodyweight had the rs10010131 G/G genotype than placebo-treated participants with higher baseline bodyweight, which may have influenced these findings. Alternatively, the association with lower baseline BMI and greater bodyweight loss observed in the current study may be independent of DAPA + ExQW treatment, as lower baseline BMI is associated with greater bodyweight loss following dietary [ 55 ] and surgical [ 56 ] interventions.…”

Determinants of successful lifestyle change during a 6-month preconception lifestyle intervention in women with obesity and infertility

“…Many trials and observational cohorts have reported that a higher baseline BMI is associated with greater (initial) weight loss or weight loss maintenance over time [53–55]. However, reviews of BMI trajectories of weight loss [56] and BMI classes [57] reported no associations between those with an initial loss trajectory or higher BMI classes and weight loss outcomes. This is in line with our findings that baseline BMI was not an independent predictor of weight loss success.…”

Weight loss and mortality risk in patients with different adiposity at diagnosis of type 2 diabetes: a longitudinal cohort study

“…Our study reveals that patients who were obese at the time of T2DM diagnosis experienced a steady rise in body weight before diagnosis, an observation which is consistent with a previous study in Pima American Indians 14 . While only two studies either statistically modelled the trajectory of body weight or evaluated one-point observed weight 10 years prior to diagnosis of T2DM, our study explored the 6-monthly trajectory of observed body weight during the 36 months prior to diagnosis, accounted for prevalence of diseases, and assessed weight change over 24 months post diagnosis of diabetes 15 , 34 . We also note that normal weight and overweight patients experienced significant weight loss during 6 months before diagnosis of diabetes—a rather common, yet unexplained clinical manifestation.…”