Age-related changes in behavioural and neural variability in a decision-making task.

Overweight (body mass index (BMI) > 25) and obesity (BMI > 30) are highly prevalent among adults worldwide: in 2022 an estimated 2.5 billion adults overweight (43%), of whom 16% were obese. Obesity contributes to over 200 health conditions among which are cardiovascular disease, type 2 diabetes, and cancer [, ]. Increasingly, obesity is recognized as a chronic, relapsing, noncommunicable disease []. Obesity is a complex multifactorial disease characterized by chronic dysregulation of energy balance, resulting from a sustained mismatch between energy intake and energy expenditure. This dysregulation is shaped by the interaction between biological susceptibility, including neuro‐endocrine and metabolic regulation, dietary behavior and physical activity, and broader environmental and societal factors, such as food availability, marketing and pricing and policy contexts [, ]. Even modest weight loss can yield important health benefits, including reductions in cardiovascular risk factors [], and lowering the risk of certain cancers (e.g., Yates et al. []). While behavioral interventions can successfully induce short‐term weight loss, many people struggle to maintain weight loss and often regain weight even when interventions are well designed and adherence is high []. Importantly, even sustained effort frequently fails to prevent weight regain, and behavioral interventions typically yield small effects that attenuate over time when assessed across multiple years []. This limited durability is partly explained by biological adaptations that occur following weight loss, which promote weigh regain. After weight reduction, changes in appetite‐regulating hormones, energy expenditure, and neurobiological reward pathways promote increased hunger and reduced metabolic rate, effects that may persist for years []. As a result, weight regain is common even among individuals who continue to engage in health‐promoting behaviors. Behavioral strategies therefore operate within biological constraints that actively promote weight regain, limiting the magnitude and durability of intervention effects. Sustained weight‐loss maintenance, and thus effective long‐term obesity management, requires ongoing effort []. An earlier systematic review and meta‐analysis by Dombrowski and colleagues has shown that behavioral interventions can contribute to small, but persistent weight differences over time []. Generally, behavior change interventions are complex multi‐component approaches offering a great variety of intervention types, targeting different behavioral factors such as knowledge, motivation, skills, and self‐efficacy, using different delivery formats (including face‐to‐face or online, individual or group setting, and digital apps), based on different theoretical models (such as the health belief model, theory of planned behavior, or the self‐determination theory) [, , ] and/or the different behavior change techniques (BCTs) they employ. A BCT is defined as “an observable, replicable and irreducible component of an intervention designed to alter or redirect causal processes that regulate behaviour” []. Importantly, within the context of obesity as a chronic, relapsing disease, BCTs should not be viewed as mechanisms that can fully counteract the biological adaptations promoting weight regain. Rather, specific BCTs may support individuals in sustaining behavioral changes for longer, help attenuate the rate or magnitude of weight regain, or contribute to clinically meaningful differences in weight outcomes relative to comparison conditions. Although Dombrowski et al. [] demonstrated that behavioral interventions can lead to small but persistent weight differences over time; they did not examine which specific BCTs contributed to long‐term weight loss maintenance. However, they underscored that to bridge the gap between behavior change and behavioral maintenance, it is essential to understand which (combination of) BCTs should be employed in interventions []. Previously the BCTs “Feedback on behaviour,” “Goal setting,” and “Graded tasks” were associated with initial weight loss [, ]. However, it remains unclear whether particular BCTs support longer‐term weight loss []. Understanding which BCTs in behavioral interventions contribute to both (1) initial weight loss and (2) a maintained weight loss may help clarify the role and limitations of behavioral intervention components in obesity management.