y Conceptualizations of obesity vary across different regions of the world. In many cases, waist-to-hip ratio is considered a more reliable metric than body mass index (BMI) because it better reflects central adiposity, which is more strongly linked to cognitive decline and cardiovascular risk. Individuals with elevated BMI do not necessarily exhibit reduced cognitive function, particularly if they belong to higher socioeconomic groups. y Dietary restrictions such as calorie restriction and intermittent fasting are not the only interventions available for people living with obesity. Other approaches include physical activity programmes (e.g. resistance training), psychological interventions (e.g. cognitive behavioural therapy), multidomain lifestyle interventions and pharmacological treatments. However, dietary restriction was the only intervention for which new evidence related to dementia risk and cognitive decline was identified as part of this guideline update. y Weight reduction efforts should be aligned with existing WHO guidance (107) and global mandates (109,111). WHO guidance on managing and treating obesity applies to all non-pregnant adults with obesity.

y Health systems should ensure the availability of appropriate, evidence‑informed support for weight management (including dietary advice and physical activity components), delivered by trained providers and adapted to local capacity and resources. y Dietary restriction interventions are feasible and can be adapted to various settings, but sustainability and accessibility may vary depending on health care infrastructure and cultural norms. Additionally, adherence to dietary restrictions may not be in the person’s control; therefore, population- and system-level barriers must be identified and addressed. y Implementation must consider disparities in access to healthy food and health care services, especially in LMIC, where dementia prevalence is rising. y Dietary restriction should be used cautiously in older adults owing to potential adverse effects; restriction requires ongoing monitoring by health care professionals to ensure that it is safe and appropriate. y Interventions should be tailored to local cultural contexts to ensure acceptability and effectiveness (121,122).

Management of obesity should be offered to all adults living with obesity, in line with WHO guidance. WHO guidance applies to all non-pregnant adults with obesity. Clinical practice: y Guideline on the use of glucagon-like peptide-1 (GLP-1) therapies for the treatment of obesity in adults (30) Service delivery and care pathways: y Health service delivery framework for prevention and management of obesity (31) Public health and policy: y WHO acceleration plan to stop obesity: a joint WHO/UNICEF operational model for designing and implementing the response (32,33) y Recommendations for the prevention and management of obesity over the life course (34) y Global action plan for the prevention and control of noncommunicable diseases (35)