Obesity is a chronic, complex disease characterised by excessive fat accumulation that presents a risk to health. WHO defines it as a BMI of 30 or above, though waist circumference and body fat distribution are also important. The 2022 WHO/Lancet NCD-RisC study found that more than 1 billion people globally now have obesity — with childhood and adolescent obesity quadrupling since 1990.

Obesity results from a sustained energy imbalance — more calories consumed than expended — but this imbalance is shaped by far more than individual choices. Genetics, gut microbiome, sleep, stress, medications, food environments (availability, affordability, marketing of ultra-processed foods), built environments (walkability, green space) and social inequalities all profoundly shape body weight. This complexity is why moralising about "willpower" is both scientifically wrong and clinically unhelpful.

What diseases does obesity cause?

Obesity is a risk factor for: type 2 diabetes (obesity accounts for ~80% of the type 2 diabetes burden); cardiovascular disease (heart attack, stroke, hypertension); at least 13 cancers (including breast, colorectal, endometrial, kidney and liver cancer); sleep apnoea; non-alcoholic fatty liver disease and cirrhosis; osteoarthritis; fertility problems; depression and anxiety; and severe COVID-19. The global economic cost is estimated at over $2 trillion per year.

Are GLP-1 drugs (Ozempic, Wegovy) safe and effective for obesity?

Yes — at the higher doses approved specifically for obesity management, GLP-1 receptor agonists (semaglutide/Wegovy, tirzepatide/Zepbound) produce 15-25% weight loss in clinical trials — the largest effect ever demonstrated by a medical therapy for obesity. They also reduce cardiovascular events, sleep apnoea severity and kidney disease progression. Side effects are mainly gastrointestinal (nausea, vomiting) and generally subside. They are approved by FDA, EMA and other regulators for chronic obesity management.

What is bariatric surgery and who is eligible?

Bariatric surgery modifies the anatomy of the stomach or intestines to reduce food intake and calorie absorption. The most common procedures are sleeve gastrectomy and gastric bypass. It produces 25-40% weight loss, achieves type 2 diabetes remission in 50-80% of cases and is highly cost-effective for severe obesity. IFSO guidelines recommend it for adults with BMI >=35 with obesity-related conditions, or BMI >=40. It remains unavailable to the vast majority of eligible people in LMICs.

Can obesity be prevented?

Yes — through population-level policies that make healthy choices easier and reduce exposure to obesity-promoting environments: taxation of sugar-sweetened beverages (shown to reduce consumption by 20-30%); mandatory front-of-pack nutrition labelling; restrictions on marketing of unhealthy foods to children; reformulation of processed foods; active transport infrastructure; and school-based nutrition and physical activity programmes. Individual interventions alone cannot reverse an epidemic driven by environmental and systemic factors.

Why is obesity increasing in LMICs?

Nutrition transition — the shift from traditional diets to high-calorie, low-nutrient ultra-processed foods — is occurring faster in LMICs than it did in high-income countries, driven by trade liberalisation, urbanisation and aggressive marketing by the food industry. The double burden of malnutrition (undernutrition and obesity coexisting) now affects most LMICs. Access to obesity treatment — including GLP-1 medicines at costs exceeding $1,000/month — is essentially non-existent in these settings.

What is the relationship between obesity and mental health?

Obesity and mental health are bidirectionally linked. Depression and anxiety increase the risk of obesity through emotional eating, reduced physical activity and medication side effects. Obesity increases the risk of depression through biological mechanisms (adipokine-mediated inflammation) and through weight stigma, discrimination and reduced quality of life. Effective obesity management requires integrated physical and mental health approaches.

How does childhood obesity develop?

Childhood obesity is driven by the same environmental factors as adult obesity, amplified by developmental vulnerabilities. Key drivers include formula feeding (vs breastfeeding), introduction of sugar-sweetened beverages and ultra-processed foods in early childhood, excessive screen time, reduced physical activity and sleep deprivation. The WHO Commission on Ending Childhood Obesity (ECHO) report provides a comprehensive framework. Interventions in the first 1,000 days of life have the highest impact.

What is the WHO Acceleration Plan to Stop Obesity?

The WHO Acceleration Plan to Stop Obesity (2022) is the global framework for addressing the obesity epidemic. It identifies six priority focus areas: creating healthy food environments; creating active environments; providing weight management programmes; supporting optimal nutrition in early life; using behaviour change communication; and building enabling health systems. It calls on governments to implement evidence-based policies rather than relying on individual behaviour change.

What is weight stigma and why does it matter?

Weight stigma is negative attitudes and discrimination towards people with obesity — in healthcare, employment, education and social settings. It is pervasive and has serious health consequences: it increases psychological distress, reduces healthcare seeking, worsens eating behaviours and physiologically activates stress pathways that worsen metabolic health. Major medical societies (EASO, TOS, IFSO) have issued position statements calling for weight-stigma-free care as a clinical standard.

How does GMJ News cover obesity?

GMJ News tracks GLP-1 drug developments, WHO Acceleration Plan implementation, bariatric surgery evidence, and the equity dimensions of obesity treatment access. The Supplement Desk also addresses nutrition and weight management supplements with mandatory evidence standards. Obesity is an emerging public health challenge in Georgia as dietary patterns westernise.

Home › Topics › Obesity

Obesity

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

More than one billion people worldwide now live with obesity — about 1 in 8 — including some 890 million adults, and adolescent obesity has quadrupled since 1990 (WHO/Lancet 2024). Obesity drives type 2 diabetes, cardiovascular disease, at least 13 cancers and premature death, yet it is a chronic disease shaped by food environments, not a personal failing — the framing of the WHO Acceleration Plan to Stop Obesity. The therapeutic landscape is being transformed by GLP-1 receptor agonists, raising urgent questions of access, cost and long-term evidence that GMJ News tracks alongside the policy levers: food taxes, marketing restrictions and school nutrition.

Key messages

Global epidemic

More than 1 billion people — 1 in 8 globally — now live with obesity, and the number of adults with overweight or obesity exceeds 2.5 billion. Obesity has tripled since 1975 (WHO/Lancet 2024).

Not a personal failing

Obesity is a chronic, complex disease shaped by genetics, physiology, food environments, sleep, stress and socioeconomic determinants — not a failure of willpower. WHO's Acceleration Plan treats it explicitly as a disease requiring medical and policy responses.

Disease driver

Obesity is a primary driver of type 2 diabetes, cardiovascular disease, at least 13 cancers, sleep apnoea, osteoarthritis, fatty liver disease and depression — costing health systems trillions annually.

GLP-1 revolution

GLP-1 receptor agonists (semaglutide, tirzepatide) produce 15-25% weight loss in clinical trials — the most effective medical therapy ever demonstrated for obesity. They also reduce cardiovascular events, sleep apnoea and kidney disease progression.

WHO Acceleration Plan

The WHO Acceleration Plan to Stop Obesity (2022) calls for action across six focus areas: healthy food environments, active environments, weight management programmes, early life nutrition, behaviour change support, and supportive health systems.

Equity challenge

Obesity disproportionately affects lower-income populations and countries — increasingly LMICs — where ultra-processed food is heavily marketed and healthy options are expensive or unavailable. Access to GLP-1 medicines in LMICs is virtually zero.

Key statistics

1B+

people with obesity globally

WHO/Lancet 2024

2.5B

people overweight or obese

WHO/Lancet 2024

increase in obesity since 1975

WHO

cancer types linked to obesity

IARC

15-25%

weight loss with GLP-1 drugs

NEJM trials 2021-23

$2T

global economic cost/year

McKinsey 2023

Global adult obesity prevalence (%) 1975-2022 — WHO/NCD-RisC

Source: NCD Risk Factor Collaboration (NCD-RisC) / WHO. Age-standardised obesity prevalence (BMI >=30 kg/m2).

Glossary of key terms

BMI
WHOBody mass index — weight (kg) divided by height squared (m2). WHO classifies overweight as BMI 25-29.9 and obesity as BMI >=30. BMI is a population screening tool; individual assessment requires waist circumference and clinical context.

Class III obesity
WHOSevere obesity, defined as BMI >=40 kg/m2. Associated with dramatically elevated risks of type 2 diabetes, CVD, sleep apnoea and mortality. Most eligible for bariatric surgery as a highly effective treatment option.

GLP-1 receptor agonist
FDA/EMA/WHOA class of injectable medicines (semaglutide/Ozempic/Wegovy, tirzepatide/Mounjaro) that mimic gut hormones, reduce appetite and slow gastric emptying. At high doses approved for obesity, they produce 15-25% body weight loss in clinical trials.

Bariatric surgery
IFSOSurgical modification of the stomach or intestines to induce substantial weight loss — including gastric bypass, sleeve gastrectomy and adjustable gastric banding. Produces 25-40% body weight loss, often achieving type 2 diabetes remission. Highly cost-effective for severe obesity.

Obesogenic environment
WHOAn environment in which food choices, physical activity opportunities and social norms promote weight gain — through the abundant availability of cheap, ultra-processed food, car-dependent design and sedentary work.

Adiposity
WHO/IDFThe degree of body fatness, particularly visceral (abdominal) fat. Central adiposity — measured by waist circumference — is a stronger predictor of cardiometabolic risk than overall BMI and is particularly important in Asian populations at lower BMI thresholds.