**Background:** Obesity is recognized by the WHO as a chronic disease (ICD-10 E66) with increasing incidence, exacerbated by the COVID-19 pandemic. Despite its prevalence, obesity is underdiagnosed and undertreated, partly due to physicians' lack of knowledge. This is the first joint position statement from six Polish medical societies (Polish Association for the Study on Obesity, Polish Association of Endocrinology, Polish Association of Cardiodiabetology, Polish Psychiatric Association, Section of Metabolic and Bariatric Surgery of the Association of Polish Surgeons, and the College of Family Physicians in Poland) aiming to provide comprehensive, evidence-based guidelines for the prevention, diagnosis, and treatment of obesity and its complications in adults, targeting primary care providers.
**Methods:** The expert panel conducted a literature search using PubMed/MEDLINE, Cochrane Library, Science Direct, and EBSCO databases from January 2010 to December 2022, focusing on English-language meta-analyses, systematic reviews, randomized clinical trials, and observational studies. Websites of scientific organizations (WHO, EASO) were also searched. Six main topics were defined: (1) definition, causes, and diagnosis; (2) treatment; (3) treatment of complications; (4) bariatric surgery; (5) role of primary care; and (6) recommendations for practitioners and health authorities.
**Key Results:** The statement recommends using the AACE/ACE 2016 BMI cutoffs: overweight grade 0 (BMI 25.0–29.9, no complications), obesity grade 0 (BMI ≥30, no complications), obesity grade 1 (BMI ≥25 with at least one mild/moderate complication), and obesity grade 2 (BMI ≥25 with at least one severe complication). Visceral obesity is diagnosed by waist circumference >80 cm in women and >94 cm in men (Caucasians). Body composition via bioimpedance: obesity if fat mass >25% in men, >35% in women. Causes include environmental factors (e.g., Polish population ranked 10th in energy consumption in 2018, low fiber intake ~16 g/day vs. recommended 25 g/day), genetic factors (at least 7% of non-syndromic early-onset severe obesity due to single gene mutations), emotional eating, binge eating disorder (BED), night eating syndrome (NES), hormonal disturbances (Cushing's syndrome prevalence 0.9% in obesity, overt hypothyroidism in 14%, subclinical in 14.6%), and medication-related (glucocorticoids cause weight gain in ~70% of patients, 20% gain >10 kg; up to 80% on atypical neuroleptics gain ≥20% of normal weight). Complications include metabolic (NAFLD/MAFLD, prediabetes, type 2 diabetes, atherogenic dyslipidemia, hypertension, obesity-related glomerulopathy, hormonal disturbances), mechanical (GERD, obesity hypoventilation syndrome, sleep apnea, osteoarthritis, chronic venous disease), and others (cholelithiasis, stress urinary incontinence, asthma, depression/anxiety). Treatment goals are SMART: 5–10% weight loss in 3–6 months, with specific targets for complications (e.g., ≥5% for type 2 diabetes, ≥10% for prediabetes). The 5 A's approach (Ask, Assess, Advise, Agree, Assist) is recommended. Nutritional interventions: energy deficit of 500–600 kcal/day for ~0.5 kg/week loss, macronutrient distribution ~20% protein, 25% fat, 55% carbohydrates. Physical activity: ≥150 min/week moderate aerobic exercise, plus resistance training 2–3 times/week. Pharmacotherapy (orlistat, naltrexone/bupropion, liraglutide 3 mg/day, semaglutide 2.4 mg/week) is indicated for BMI ≥30 or ≥27 with complications, with efficacy assessed at 3 months (≥5% weight loss, or ≥3% in type 2 diabetes). Bariatric surgery criteria: BMI >40, or BMI 35–39.9 with complications (or regardless of complications per latest guidelines), or BMI 30–34.9 with uncontrolled type 2 diabetes. Preoperative weight loss of 5–10% is recommended. Postoperative monitoring includes nutritional assessment (vitamin D, B12, thiamine, folic acid, calcium, iron, zinc, copper) at 3, 6, and 12 months, then annually.
**Clinical Implications:** This statement provides a practical framework for primary care physicians to diagnose and manage obesity as a chronic disease. It emphasizes the need for systematic screening (annual BMI and waist circumference), assessment of psychological factors (emotional eating, BED, NES, depression using HADS), and individualized treatment plans combining lifestyle, pharmacotherapy, and surgery. It highlights the importance of multidisciplinary care and addresses barriers such as time constraints (10-minute consultations in Poland) and lack of specialist referral centers. The recommendations aim to improve obesity care by shifting from a weight-centric to a health-centric approach, with specific weight loss targets for comorbidities. The statement also calls for systemic changes, including establishing an obesitology subspecialty and regional referral centers.