Obesity in adults: overview of a clinical practice guideline for South Africa

Introduction

Obesity is driven by complex factors and represents a growing public health challenge especially in South Africa. Despite rising prevalence, evidence-based treatment guidelines remain scarce, and access to effective interventions is limited in resource constrained settings (1, 2). This overview reports on the South African adaptation of the Canadian Adult Obesity Clinical Practice Guideline (CPG). Drawing on locoregional evidence, we offer pragmatic, contextually interpreted guidance for South Africa, highlighting local research gaps and controversies. Where evidence is limited — particularly around HIV-associated weight trajectories and cultural perspectives — we acknowledge uncertainties while providing feasible recommendations. This guideline addresses the need for culturally appropriate, resource-sensitive obesity management in an African healthcare setting.

Guideline development

The South African Clinical Practice Guideline for Treatment of Adult Obesity was developed by a multidisciplinary committee (endocrinologists, surgeons, public-health practitioners, mental health experts, dietitians, primary-care clinicians, medical researchers and individuals with lived experience) and followed a pre-specified process (3, 4). Professional and patient society invitations and endorsements were secured, and active engagement with government established. Ethical approval was granted by Stellenbosch University’s Health Research Ethics Committee (Ref. X24/07/020).

A hybrid GRADE-ADAPTE approach was used: GRADE principles guided appraisal of evidence quality and recommendation strength; the ADAPTE framework provided structured contextualization without de novo development when suitable guidance existed in the Canadian guideline (5). Decision rules were standardized to (1): adopt fully applicable recommendations (2); adapt recommendations requiring contextual changes; and (3) exclude recommendations with regulatory, availability, or feasibility barriers. Where updated external consensus statements altered the evidence landscape, such as for indications for metabolic and bariatric surgery (MBS), recommendations were revised with permission.

Internal peer review ensured consistency of chronic disease framing and person-first language, clarity of clinician actions in resource-variable (public vs private) settings, and alignment with South Africa’s Obesity and Non-Communicable Disease (NCD) strategies (6). External peer-review was performed by Obesity Canada with further chapter-specific blinded peer review performed by local reviewers. The guideline was published in a special issue of the South African Medical Journal in November 2025 (7, 8). This article serves as an overview of the published guideline, specifically highlighting aspects for future review.

Dissemination is planned by means of professional training workshops and a planned postgraduate qualification, integration into medical curricula, partnerships with primary-care networks and healthcare facilities, and policy engagement with provincial and national health departments and funders. Decision-support tools, care pathways, multilingual patient resources, and audit indicators are in development with societal and digital experts— especially pertinent given the rapidly evolving pharmacotherapy landscape.

Guideline chapters

Reducing weight bias in obesity management, practice and policy

Weight bias, stigma, and discrimination are pervasive, harming people living with obesity (PLWO) across society and healthcare (9). Explicit, implicit, and internalized bias are linked to care avoidance, poorer mental health, maladaptive coping, adverse physiological markers, and higher mortality (10). Clinician bias reduces access to appropriate care, patient education, and preventive screening, while narratives oversimplifying obesity as individual choice reinforce stereotypes and widen inequities (10, 11).

Effective bias-reduction requires multifaceted strategies: education on non-modifiable causes, empathy-building, peer-modeling, empowerment, and clinic environmental changes (9, 12).

Policymakers should avoid stigmatizing messaging, reject weight as a behavior-change target, and support anti-discrimination measures.

Recommendations were adopted from the Canadian CPG (Table 1).

Table 1. Recommendations and contextualisation.

HCP, health care practitioner; PLWO, people living with obesity; SA, South Africa; OT, occupational therapy; BMI, body mass index; ADHD, Attention Deficit Hyperactivity Disorder; MNT, medical nutrition therapy; BP, blood pressure; T2DM, type 2 diabetes mellitis; OSA, obstructive sleep apnea; MBS, metabolic and bariatric surgery); QoL, quality of life; PA, physical activity; MBS, metabolic and bariatric surgery; MASLD, metabolic associated steatotic liver disease; MDT, multidisciplinary team; PHP, primary healthcare provider.

Epidemiology of adult obesity

In South Africa (SA), between 1998 and 2017, adult obesity prevalence rose by 38% to 28.0% with the rate of increase being double in women (29.5%→42.6%) compared to men (10.1% →12.1%) (27). Similar trends were observed for central/abdominal obesity, with higher rates of increase in women than men (60%→77.2%; 21.6%→26.3% respectively) and higher rates of increase observed in rural SA provinces. Epidemiological data in SA is dated with the last national survey conducted in 2016/2017 (28).

Obesity is associated with increased risk of diseases such as cardiovascular disease, diabetes and cancer, and accounted for 11.1% of total deaths and 6.9% of disability adjusted life years in 2012 (29–31). Public-sector treatment costs were estimated at ZAR33.194 million in 2020 (0.67% of gross domestic product) and private insurer cost at ZAR21.8 billion in 2022 (32). Given increasing obesity trajectories and large SA data gaps, regular surveillance is required to reduce the unequal burden and escalating costs.

Recommendations were adopted from the Canadian CPG (Table 1).

The science of obesity

Obesity is a complex chronic disease in which abnormal or excess body fat (adiposity) impairs health, increases the risk of long-term medical complications, and reduces lifespan (33). A complex interaction of genetic, metabolic, behavioral, and environmental factors culminate in dysfunction of energy balance (34). The brain regulates energy and appetite in the hypothalamus (homeostatic control), mesolimbic system (hedonic drive), and frontal lobe (cognitive functioning) with all regions integrating signals from the gut and adipose tissue (35, 36).

Obesity may be classified as genetic, secondary, or primary obesity (Figure 1), the latter with non-modifiable causes and potentially modifiable contributors. Two interrelated concepts underpin obesity pathophysiology: the global rise in body weight and the personal fat threshold (37). Genetic susceptibility, combined with a modern toxic environment and poor diet quality disrupts energy balance, driving population weight gain and pushing individuals beyond their personal fat threshold (38). Visceral fat is metabolically distinct from subcutaneous adipose tissue, exhibiting greater insulin resistance, pro-inflammatory activity, and stronger associations with cardiometabolic disease (39).

Prevention and harm reduction of obesity (clinical prevention)

Obesity prevention requires action across primary, secondary and tertiary levels, recognizing causes and contributors beyond diet and exercise including medications and social and environmental determinants (40).

Primary prevention evidence is strongest in pregnancy where interventions lower the risk of excessive gestational weight gain, particularly when delivered within prenatal care (41). Secondary prevention emphasizes early detection and prevention of further weight gain in early stages while, tertiary prevention aligns with weight-loss management for established comorbidity.

While smoking cessation results in weight gain, cardiovascular and mortality benefits outweigh the risk, and short-term strategies may limit weight gain (42). Medication-associated weight gain (antipsychotics, antidepressants, antihyperglycaemics, corticosteroids and antiretrovirals) warrants choosing weight-neutral agents or instituting monitoring and behavioral support (43). Menopause and young adulthood are high-risk stages for weight gain. Behavioral programs can attenuate gain in midlife women (44) while effects in young adults are modest and not sustained (45).

Enabling participation in activities of daily living for people living with obesity

PLWO frequently face barriers to self-care, mobility, and healthcare participation (46). Fall risk assessment using the Falls Efficacy Scale is recommended across obesity classes (13). and routine skin integrity screening with practical moisture and friction reducing strategies should be instituted (47). Timeous referral to occupational therapy, physiotherapy and biokinetics supports independence, equipment selection, and physical activity counselling – though local SA evidence and access remain limited (48).

Recommendations were adopted from the Canadian CPG (Table 1).

Assessment of people living with obesity

Goals of assessment in PLWO are to confirm the diagnosis, determine disease severity, identify comorbidities and contributors to weight, and guide management in a stigma-free environment. Healthcare providers (HCPs) should initiate discussions with empathy, using frameworks such as the 5As (Ask, Assess, Advise, Agree, Assist) to explore readiness, set goals, and support long-term behavior change (14).

Screening relies on anthropometric measures and while body mass index (BMI) remains widely used it cannot distinguish fat from muscle or indicate fat distribution. Combining BMI with waist circumference or waist-to-height ratio better defines cardiometabolic risk (33). Ethnic-specific cut-offs are critical as evidenced by increased cardiometabolic risk in Asian populations at lower BMI thresholds (49). For South Africans, WHO thresholds apply, even though emerging evidence suggests different waist circumference cut-points for black populations (50).

Assessment includes an obesity-centered history (medical, weight trajectory, nutrition, physical activity, mental health, sleep, substance use, and social context) and a focused physical examination (anthropometry, cardiovascular, musculoskeletal, endocrine systems and skin). Laboratory investigations should screen for diabetes, dyslipidaemia, steatotic liver disease - including the FIB-4 score (51), and obstructive sleep apnea (OSA), guided by clinical presentation.

Tools such as the Edmonton Obesity Staging System (EOSS) provide a multidimensional view of disease impact beyond BMI, predicting morbidity and mortality (17). The 4Ms framework (Mental, Mechanical, Metabolic, Monetary) further helps identify drivers, complications, and barriers (52). Patient-reported outcome measures (PROMs) are increasingly recommended to capture quality-of-life domains (53).

Recommendations were adapted from the Canadian CPG, with updates in terminology only (Table 1).

The role of mental health in obesity management

Individuals with mental illness face higher risks of obesity due to biological, psychological, and social factors, compounded by weight-promoting psychotropic medications (54). Conversely, obesity increases vulnerability to depression, anxiety, binge-eating disorder (BED), and attention deficit hyperactivity disorder (ADHD) (54, 55).

Screening for mental illness in PLWO is essential, particularly before MBS, as psychiatric comorbidities can influence postoperative outcomes and adherence (56). Antipsychotic-induced weight gain is a significant clinical issue in those with mental illness and behavioral and lifestyle interventions show modest benefit (57), while pharmacological options may mitigate risk (58).

Recommendations were adopted from the Canadian CPG (Table 1).

Medical nutrition therapy in obesity management

Medical nutrition therapy (MNT) focuses on improving health outcomes rather than solely achieving weight loss, fostering a positive relationship with food. Interventions should be personalized, culturally appropriate, affordable, and sustainable, and ideally delivered by registered dietitians if available.

There is no single best dietary approach and success depends on long-term adherence (59). Options include calorie-restricted plans, macronutrient-based approaches, and patterns such as Mediterranean, vegetarian, Nordic, and Portfolio diets which may improve glycaemic, blood pressure, and lipid profiles (60). Food-based strategies - emphasizing pulses, fruits, vegetables, nuts, whole grains, and dairy—also show benefits (61). Meal replacements and intermittent fasting may support short-term weight loss but require medical oversight especially in older adults or those at risk of malnutrition (62, 63).

Caloric restriction can achieve initial weight loss but is difficult to sustain due to physiological adaptations that increase hunger and promote weight regain (64). Non-restrictive approaches, including mindful eating and Health at Every Size^® (HAES^®) principles aim to reduce weight stigma and improve psychological wellbeing, though evidence remains limited (65). Behavioral support is essential, with intensive lifestyle programs demonstrating significant improvements in overall health (66).

Recommendations were adapted from the Canadian CPG, improving concepts and terminology only (Table 1).

Physical activity in obesity management

The World Health Organization (WHO) defines physical activity as bodily movement by skeletal muscles that requires energy expenditure (67). Physical inactivity remains one of the leading modifiable risk factors for mortality (68).

While exercise alone produces modest weight reduction (2–3 kg), its value lies in improving health, mobility, and muscle mass. It reduces abdominal visceral fat and ectopic fat, even without significant weight change, and improves insulin sensitivity, blood pressure, and lipid profiles (69).

Aerobic and resistance training enhance cardiorespiratory fitness, strength, and muscle mass preservation, which is critical during weight loss interventions. High-intensity interval training (HIIT) may improve fitness and metabolic markers in less time, though its superiority for fat loss remains unclear, and behavioral support is essential for sustained change (66, 70).

South African guidance align with the WHO Global Action Plan on Physical Activity (71) and the National Strategy for Obesity 2023–2028 (6), which aims to reduce physical inactivity by 15% by 2030.

Recommendations were adopted from the Canadian CPG (Table 1).

Effective psychological and behavioral interventions in obesity management

Psychological and behavioral interventions are essential for effective obesity management, as sustained lifestyle change is key to improving health and quality of life. These interventions aim to support PLWO in adopting and maintaining healthier eating patterns, physical activity, and treatment adherence. MNT and physical activity interventions rarely succeed without addressing psychological drivers of behavior (66).

Behavioral interventions are most effective when they are person-centered, responsive to the expressed needs of PLWO and combine behavior modification (goal setting, self-monitoring, problem solving), cognitive strategies (reframing unhelpful beliefs, enhancing self-efficacy), and value-based approaches that align with personal priorities (72). Interventions should be culturally adapted and build executive control skills and resilience - planning, impulse regulation, and problem solving - while managing weight-loss expectations to prevent disengagement (73). Acceptance and Commitment therapy and compassion-focused strategies help address internalized weight bias and stigma, which often undermine motivation and outcomes. Digital tools may augment interventions, though uptake remains a challenge (74).

Recommendations were adopted from the Canadian CPG (Table 1).

Pharmacotherapy for obesity management

Pharmacological agents used in treatment of adults with a body mass index (BMI) ≥30 kg/m² or ≥27 kg/m² with adiposity-related complications is not a stand-alone solution but part of holistic obesity management alongside MNT, physical activity, psychological support and MBS (75, 76).

In South Africa, five drugs are approved for chronic obesity management: orlistat, liraglutide, naltrexone/bupropion, semaglutide and tirzepatide (Table 2). Regulatory approval of medication has changed significantly since publication of the guideline and updates are being drafted. Agents differ in mechanism, efficacy, tolerability, and cost. Phentermine is registered for short-term use only. Emerging therapies such as cagrilintide (amylin analogue), and dual and triple agonists show promise. The use of off-label or unapproved therapies is strongly discouraged.

Table 2. Pharmacotherapy for obesity in adults in South Africa.

CI, Confidence Interval.

Pharmacotherapy benefits extend to comorbidities such as cardiovascular disease, T2DM, OSA, steatotic liver disease, and osteoarthritis (77, 78). However, response is heterogeneous and discontinuation leads to weight regain, underscoring the need for long-term use. Recommendations were adopted from the Canadian CPG (Table 1) though this was subsequently updated (75).

Metabolic and bariatric surgery: selection and preoperative work-up

Surgical treatment is the most robust long-term treatment for obesity, outperforming behavioral and medical interventions (18, 20). Indications include a BMI >35 kg/m² regardless of comorbidities, and BMI 30–34.9 kg/m² with metabolic disease (19).

Preoperative assessment include screening for micronutrient deficiencies (especially vitamin D and iron), OSA, cardiac and pulmonary risk, and mental health status (15, 22, 79). Smoking cessation is encouraged to reduce postoperative complications (80). A low-calorie diet for 2–3 weeks before surgery helps reduce liver size and operative difficulty and medication adjustment especially for T2DM and anticoagulation during this time is critical (81). Recommendations were adopted from the Canadian CPG (Table 1).

Metabolic and bariatric surgery: surgical options and outcomes

MBS achieves 20–40% total weight loss and high remission rates for T2DM, hypertension, dyslipidaemia, OSA, and steatotic liver disease (19). It improves quality of life, reduces cancer risk, and lowers long-term mortality by up to 49%, with median life expectancy gains of 6–9 years (19). Published outcomes after MBS from South African series are limited but consistent with international reports (82, 83). Although MBS was historically only accessible through private health insurance, public centers now have established MBS programs (84).

The most common procedures performed are sleeve gastrectomy and Roux-en-Y gastric bypass. Sleeve gastrectomy is technically simpler with a 30% risk of developing gastroesophageal reflux postoperatively, while RYGB carries a risk of internal herniation and stomal ulceration but remains the gold standard for sustained metabolic benefits (85). Endoscopic sleeve gastroplasty is now recognized as a less invasive option in the treatment armamentarium (86). Emerging options are the single-anastomosis duodenal-ileal bypass and one-anastomosis gastric bypass, performed only when patient outcomes are captured in a national registry (87, 88).

MBS should be planned following multidisciplinary discussion, considering goals, comorbidities, and perioperative and long-term risks. Perioperative care is provided by a trained and accredited team following enhanced recovery after surgery protocols (89). Recommendations were adapted from the Canadian CPG, as indications were updated (Table 1).

Metabolic and bariatric surgery: postoperative management

Postoperative care is shared between the MBS multidisciplinary team, primary healthcare providers, and PLWO. Priorities include lifelong adherence to nutrition plans, adequate protein intake, vitamin and mineral supplementation, and regular physical activity (90). Pregnancy should be delayed for 12–18 months after surgery (23).

Annual micronutrient monitoring and replacement is well defined to limit deficiencies in iron, vitamin B12, vitamin D, calcium, and fat-soluble vitamins (22). Long-term complications include dumping syndrome, bone loss, and nephrolithiasis. Psychological support aims to diagnose and treat depression, body image issues and addiction. Weight regain occurs in up to 35% of patients and should be managed through MNT reinforcement, psychological support, and, if necessary, pharmacotherapy or surgical revision (91). Recommendations were adopted from the Canadian CPG (Table 1).

Primary care and primary healthcare in obesity management

Primary healthcare providers play a pivotal role as first contact for PLWO. Effective care demands respectful, patient-centered conversations that avoid stigma and use structured frameworks, collaborative deliberation, and motivational interviewing (14). These approaches prioritize health-focused goals, such as improved function and quality of life, over weight alone.

Multi-component interventions combining MNT, physical activity and behavioral strategies outperform single-component approaches (92). Cultural tailoring and health literacy are essential for engagement, particularly in diverse and resource-constrained settings (93). System-level changes - training of primary health care providers, creating referral pathways, and leveraging technology-enabled models - are critical for scalability and sustainability. Recommendations were adopted from the Canadian CPG (Table 1).

Commercial products and programs in obesity management

The weight loss industry is vast and often characterized by unrealistic claims. While some commercial programs may achieve modest short-term weight loss and marginal glycemic improvements, evidence for sustained benefits - or impact on blood pressure and lipids - is lacking (94). Over-the-counter supplements are widely available but unproven in high-quality trials and may pose health risks (95). Healthcare providers should familiarize themselves with local offerings and guide patients toward safe, evidence-based options, while PLWO should critically evaluate commercial claims. Recommendations were adapted from the Canadian CPG and specific products and programs were not mentioned (Table 1).

Emerging technologies and virtual medicine in obesity management

Emerging technologies in obesity management encompass digital health tools such as telemedicine, mobile apps, wearable devices, web-based platforms, and artificial intelligence (AI). Innovations enhance accessibility, convenience, and cost-effectiveness while maintaining supportive elements of conventional care. Interventions include self-monitoring, goal setting, and personalized feedback delivered via smartphones, text messaging, or wearable trackers.

Evidence suggests these strategies can improve short-term weight loss, particularly when combined with face-to-face care, but long-term data remain limited (96). Hybrid models integrating digital and in-person approaches show promising results for weight reduction and physical activity and may be especially applicable to SA. Challenges include short study durations, methodological limitations, and underrepresentation of men and diverse populations. Ethical considerations such as data privacy (POPIA compliance), digital literacy, and equitable access are critical, especially in resource-limited settings (97). Recommendations were adopted from the Canadian CPG (Table 1).

Weight management over the reproductive years for adult women living with obesity

Weight management during the reproductive years is critical for women with obesity due to increased risks of infertility, gestational diabetes, hypertensive disorders, caesarean delivery, and adverse neonatal outcomes (98, 99). During pregnancy, achieving guideline-concordant gestational weight gain of 5–9 kg for BMI ≥30 kg/m² is essential, as excess gain is linked to complications such as macrosomia, preterm birth, and postpartum weight retention (24). Evidence supports behavioral interventions as the most effective strategies, while pharmacotherapy is generally avoided (100). Postpartum weight retention is common and contributes to long-term obesity and complications in future pregnancies, while breastfeeding offers health benefits but may require additional support for women with obesity (26). Recommendations were adopted from the Canadian CPG (Table 1).

Model of care, referral & health-system integration

Management of obesity follows disease classification - genetic, secondary and primary (Figure 1). For primary obesity, the “path in” is driven by environmental factors such as sleep habits, stress, medications and early-life programming. This differs from the “path out”, which targets the final common pathway of increased appetite. Effective treatment therefore prioritizes appetite-modulating therapies including GLP-1 receptor agonists and MBS - supported by MNT, physical activity and behavioral and psychological care (34). Prevention and harm-reduction strategies operate at population and primary health care levels. Early detection and non-stigmatizing care should be honored throughout.

Research gaps and future directions

Culture and ethnicity

Limited local evidence suggests a tendency to underestimate body weight and highlights varied perceptions of body image, body size, healthy food choices, obesity related health, and the Health Promotions Levy (Sugar Tax) (101–103).

While cultural beliefs, traditional body ideals, and community norms profoundly influence obesity perceptions and treatment-seeking behaviors, literature does not adequately represent SA’s diverse ethnic groups, languages, and socioeconomic contexts. Rather than providing guidance based predominantly on high-income country research or extrapolating inappropriately from other settings, we explicitly acknowledge this evidence gap and prioritize it as a critical research area for future guideline iterations.

Obesity in people living with HIV

This guideline is placed in a context of high HIV prevalence, with nearly 6 million South Africans receiving lifelong antiretroviral therapy (ART) (104). However, evidence linking HIV infection, ART exposure, and obesity-related outcomes remains insufficient to support local guidance. People living with HIV (PWH) may have an increased risk of cardiovascular and metabolic disease, including myocardial infarction, stroke, and T2DM, which now account for the growing share of premature deaths (105–108). Prevention trials such as REPRIEVE, demonstrate targeted interventions can reduce major adverse cardiovascular events, even among PWH traditionally classified as low risk, but these alone are unlikely to offset cardiometabolic risk in the setting of prevalent and accelerating obesity (109).

Dolutegravir-based ART used by most PWH in South Africa is central to SA’s HIV program and is unlikely to be displaced in the near future (110, 111). Across African and international cohorts, dolutegravir-associated weight gain is often rapid and clinically meaningful, with disproportionate effects among women and black PWH (112, 113). SA trial data further show weight gain is accompanied by rising blood pressure, incident hypertension, and increased cardio–kidney-metabolic risk (114).

Despite these observations, three evidence gaps limit guideline development. First, the biological meaning of post-ART weight gain in PWH remains unclear. Unlike in the general population, weight gain in PWH may reflect preferential expansion of visceral and ectopic fat rather than generalized adiposity, driven by chronic inflammation, prior treatment effects, and reproductive life stages (including pregnancy and menopause) (115–117). Without SA-specific longitudinal data, clinicians cannot reliably distinguish metabolic harm from immune recovery. These uncertainties are compounded by overlapping HIV and weight stigma, where weight gain may be interpreted as wellness and weight loss as illness, delaying risk recognition and complicating counselling (118, 119).

Second, evidence is limited on when obesity-related complications emerge in PWH, by ART regimen and baseline adiposity. Third, although pharmacotherapy is well studied in the general population, their real-world integration into HIV care remains an evidence gap, particularly regarding safety, acceptability, retention, and delivery within in public-sector services (120, 121). Progress requires SA-based prospective cohorts and pragmatic studies within HIV care platforms. Without this evidence, guidance is based on imported thresholds rather than context-appropriate screening, staging, and treatment pathways for obesity in PWH.

Conclusion and recommendations

This guideline adaptation represents a landmark in South Africa’s obesity response, providing clinicians with the country’s first national evidence-based guideline for adult obesity management. The committee produced a rigorous, locally relevant guideline efficiently and cost-effectively, underpinned by a transparent GRADE-ADAPTE methodology and multidisciplinary stakeholder engagement.

Challenges remain, including the absence of routine obesity surveillance, resource constraints, and limited local research funding. Successful implementation will require integration with national NCD strategies, workforce training, community outreach, and ongoing monitoring and evaluation.

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Footnotes

Edited by: Liu Dongbo, Hunan Agricultural University, China

Reviewed by: Avivar Awasthi, Dr. Ram Manohar Lohia Institute of Medical Sciences, India

Sidrah Lodhi, King Edward Medical University, Pakistan