Obesity A Growing Global Health Crisis

Naval Kishor^1*, Piyush Gulati¹

¹Department of Medicine, All India Institute of Medical Sciences, New Delhi, India

*Corresponding Author: Naval Kishor, Department of Medicine, All India Institute of Medical Sciences, New Delhi, India, E-mail: naval435@gmail.com

Abstract

Obesity is a complex, multifactorial disease characterized by excessive body fat that increases the risk of various health problems, including heart disease, type 2 diabetes, and certain cancers. Once considered a problem of high-income countries, obesity now affects populations across the globe, including low- and middle-income nations. This article explores the causes, consequences, classification, and prevention of obesity, as well as treatment strategies. Understanding the social, environmental, and biological factors underlying obesity is crucial for effective intervention and public health policy.

Keywords: Obesity; Body mass index (BMI); Lifestyle diseases; Metabolic syndrome; Nutrition; Public health; Weight management

Introduction

Obesity has emerged as one of the most pressing public health challenges of the 21st century. According to the World Health Organization (WHO) [1], worldwide obesity has nearly tripled since 1975. In 2023, more than 1billion people were classified as obese, including over 340 million children and adolescents. Defined primarily by a body mass index (BMI) ≥30 kg/m², obesity is not just an aesthetic issue but a medical condition linked to a wide range of chronic illnesses.

While genetics play a role, the global obesity epidemic is largely driven by poor dietary habits, physical inactivity, socioeconomic changes, and urbanization. Effective prevention and management require a multi-level approach involving individuals, communities, healthcare systems, and governments.

Classification of Obesity

Obesity is typically assessed using BMI, a simple index of weight-for-height [Table 1].

BMI (kg/m²)	Category
<18.5	Underweight
18.5–24.9	Normal weight
25.0–29.9	Overweight
30.0–34.9	Obesity Class I
35.0–39.9	Obesity Class II
≥40.0	Obesity Class III

Table 1: WHO Classification of Adult BMI

Note: For children and adolescents, BMI-for-age percentiles are used.

Causes of Obesity

Poor Diet

Increased intake of high-calorie, nutrient-poor foods—rich in sugar, fats, and processed ingredients—leads to an energy imbalance and weight gain [2].

Sedentary Lifestyle

Modern conveniences have reduced physical activity levels, both in occupational and recreational settings. Screen time and desk jobs contribute significantly.

Genetics and Metabolism

Some individuals are genetically predisposed to store fat more efficiently or have slower metabolic rates, though environment remains a dominant factor.

Socioeconomic and Environmental Factors

Low-income populations often have limited access to healthy food and safe exercise spaces, increasing their risk of obesity [3].

Psychological and Hormonal Influences

Stress, depression, and hormonal disorders such as hypothyroidism or polycystic ovary syndrome (PCOS) may also contribute to obesity.

Health Consequences of Obesity

Obesity increases the risk of numerous non-communicable diseases (NCDs):

Cardiovascular disease: High blood pressure, atherosclerosis, heart attack

Type 2 diabetes: Insulin resistance is strongly linked to abdominal fat

Certain cancers: Including breast, colon, liver, and pancreatic cancer

Respiratory problems: Such as sleep apnea and asthma

Musculoskeletal disorders: Especially osteoarthritis due to increased joint stress

Mental health issues: Depression, anxiety, and social stigma

Childhood and Adolescent Obesity

Childhood obesity is of particular concern because it often leads to adult obesity and early onset of health problems [4]. Factors include sugary snacks, fast food marketing, lack of physical education, and parental influence on dietary habits.

Intervention in early life, such as promoting breastfeeding, healthy school meals, and active play, is crucial.

Prevention Strategies

Healthy Diet

Emphasize fruits, vegetables, whole grains, and lean proteins

Limit intake of added sugars, trans fats, and refined carbohydrates

Promote portion control and mindful eating

Physical Activity

WHO recommends 150–300 minutes of moderate aerobic activity per week

Encourage walking, cycling, dancing, or any enjoyable movement

Public Policy

Taxation on sugary drinks and junk food

Clear food labeling and nutritional education

Urban planning to support active transport (e.g., bike lanes, parks)

Behavioral Interventions

Counseling and support groups for weight management

Digital health tools like fitness trackers and apps

Workplace wellness programs

Treatment of Obesity

Lifestyle Modification

First-line treatment includes diet, exercise, and behavior therapy [5]. Even a 5–10% weight loss can significantly reduce disease risk.

Pharmacological Treatment

Prescription medications such as orlistat, liraglutide, orsemaglutide may be used under medical supervision.

Bariatric Surgery

For individuals with severe obesity (BMI ≥40 or ≥35 with comorbidities), procedures like gastric bypass or sleeve gastrectomy offer effective long-term weight loss.

Multidisciplinary Approach

Combining medical, nutritional, psychological, and exercise support leads to better outcomes.

Social and Economic Impact

Obesity imposes a heavy financial burden on healthcare systems due to increased treatment of chronic diseases. It also leads to reduced productivity, absenteeism, and lower quality of life. In some cultures, stigma and discrimination worsen the psychological impact, making treatment adherence more difficult.

Emerging Trends and Research

Personalized nutrition based on genetics and microbiome analysis

Digital health tools using AI for personalized coaching

Food environment studies exploring how neighborhood access to healthy food affects weight

Conclusion

Obesity is a multifaceted health condition driven by environmental, behavioral, and biological factors. It is no longer just a problem of affluence but a global epidemic requiring urgent action. Prevention must begin early and involve sustainable lifestyle changes, public health policy, and community engagement. Successful management requires empathy, multidisciplinary care, and long-term commitment. Combating obesity is not just about weight loss—it's about creating healthier societies.

Refernces

1. (2023) World Health Organization. Obesity and overweight factsheet.

2. Guh DP (2009)The incidence of co-morbidities related to obesity and overweight: A systematic review and meta-analysis. BMC Public Health 9: 88.

3. Bray GA, Ryan DH (2020) Evidence-based weight loss interventions: Individualized treatment options to maximize patient outcomes. Diabetes Obesity and Metabolism 22: 3–16.

4. (2023) CDC (Centers for Disease Control and Prevention). Childhood Obesity Facts.

5. Hall KD (2011) Quantification of the effect of energy imbalance on bodyweight. The Lancet 378: 826–837.