Overweight and Obesity: The Silent Threat Affecting Long-Term Health

• Overweight and obesity are chronic, complex conditions that affect both physical and mental health. They involve more than just body shape, impacting various bodily systems and long-term quality of life. Therefore, they require systematic care following medical principles.
• Among Asians, the risk of chronic diseases begins at a BMI over 23, even if it does not meet obesity criteria. Assessing waist circumference alongside BMI improves risk screening. Even if BMI is normal, an excessive waist circumference indicates long-term health risks.
• Bariatric surgery is a treatment option for individuals with severe obesity or multiple comorbidities. This method can aid weight loss and help balance hormones related to metabolism. However, patients must have continuous long-term follow-up and lifestyle adjustments to maximize treatment effectiveness.

Overweight (Overweight) and obesity (Obesity) refer to conditions where the body accumulates excess fat beyond what is necessary, which can impair the functioning of various body systems, including cardiovascular, metabolic, respiratory, and hormonal systems. These abnormalities increase the risk of chronic health problems and diseases over time.

Medically, overweight and obesity are not merely issues of appearance or beauty but are classified as chronic diseases requiring continuous and systematic management. Without proper care, the risk of severe complications such as cardiovascular disease, diabetes, and hypertension rises, negatively affecting long-term quality of life.

Today, global health organizations recognize obesity as a major health issue of the century. Obesity is not caused solely by overeating or lack of exercise but is a complex condition involving genetics, lifestyle behaviors, environmental factors, and internal bodily system functions. This complexity is reflected in the continuous rise of overweight and obesity rates across all age groups, from children and adolescents to adults.

Why is overweight not a minor issue?

Many believe that slight overweight is not a health problem. However, current medical evidence shows that the risk of chronic diseases begins to increase at a body mass index (BMI) above 23.kg/m2Even if it does not meet obesity criteria, excess body fat—especially abdominal fat—is linked to insulin resistance, low-grade chronic inflammation, and hormonal imbalances, all of which are key mechanisms leading to various non-communicable diseases (NCDs) over time.

Assessing overweight and obesity in Asian populations

Body Mass Index (BMI)

BMI is a basic tool to assess body weight status, calculated by dividing body weight in kilograms by height in meters squared.kg/m2For Asian populations, the risk of diabetes and heart disease occurs at lower BMI levels than Western populations, leading to the following appropriate thresholds:

BMI Calculation Formula

BMI = weight (kg) ÷ height (m)²

• BMI 18.5–22.9kg/m2: Normal weight
• BMI 23.0–24.9kg/m2: Overweight
• BMI ≥25.0kg/m2: Obesity

Using BMI criteria for Asians helps identify at-risk individuals early, even without obvious symptoms or clear obesity.

Is BMI alone sufficient?

Although BMI is widely used, in some cases—such as muscular individuals or the elderly—doctors may also consider waist circumference or body composition tests to assess abdominal fat, which is more closely related to heart disease and diabetes risk than subcutaneous fat.

Waist Circumference and Abdominal Obesity

Besides BMI, waist circumference is a key indicator of abdominal fat accumulation, directly linked to risks of heart disease, diabetes, and hypertension.

For South Asian and Chinese populations, risk waist circumference thresholds are:

• Men ≥ 90 centimeters
• Women ≥ 80 centimeters

Even with a normal BMI, exceeding these waist circumference limits indicates long-term health risks.

Causes of overweight and obesity

Obesity is not caused solely by "overeating" but results from the complex interplay of behavioral, biological, and lifestyle factors affecting energy balance and long-term body weight control.

1. Behavioral factors

Daily consumption and lifestyle behaviors play key roles in obesity development, especially:

• Eating high-energy foods rich in fats and sugars
• Regular consumption of processed foods and sugary drinks
• Lack of physical activity, such as prolonged sitting or continuous screen time

2. Biological factors

Internal bodily factors also significantly influence weight control, including:

• Genetics affecting metabolism and fat storage
• Hormonal disorders related to hunger and satiety
• Age-related hormonal changes that impact metabolism and body composition

3. Lifestyle and overall health factors

Long-term lifestyle patterns correlate with obesity risk, particularly:

• Inadequate or poor-quality sleep
• Chronic stress affecting hormones and eating behaviors
• Use of certain medications, such as steroids or some psychiatric drugs, which may cause weight gain

Dangers and complications from overweight and obesity

Overweight and obesity affect multiple body systems and are major risk factors for various chronic diseases, impacting quality of life and increasing the risk of long-term complications as follows:

1. Metabolic disorders

• Type 2 diabetes
• Insulin resistance
• Abnormal blood lipid levels

2. Cardiovascular diseases

• Hypertension
• Coronary artery disease
• Stroke

3. Other system diseases and disorders

• Non-Alcoholic Fatty Liver Disease (NAFLD)
• Obstructive Sleep Apnea
• Osteoarthritis and chronic joint pain
• Certain cancers, including breast, colorectal, and ovarian cancers

Mental health and quality of life impacts

Overweight and obesity affect not only physical health but also mental health and overall quality of life, potentially causing:

• Fatigue and reduced mobility, affecting daily activities
• Reduced self-confidence and concerns about body image
• Increased risk of depression, stress, and other mental health issues
• Overall reduced quality of life and higher risk of premature death due to complications

Approaches to proper management of overweight and obesity

Managing overweight and obesity should follow a holistic approach involving a multidisciplinary team, including doctors, dietitians, physical therapists, and other health specialists, to ensure effective, safe, and sustainable care.

1. Lifestyle modification
Suitable for individuals with a BMI between 25 and 26.9 kg/m2
Care focuses on appropriate daily behavioral changes, such as:

• Balancing and meeting nutritional needs in diet
• Reducing intake of high-fat and high-sugar foods
• Increasing physical activity and daily movement
• Ensuring adequate rest and managing stress properly

2. Medication combined with lifestyle changes
Appropriate for

• Individuals with BMI ≥ 25 kg/m2 plus comorbidities
• Or those with BMI ≥ 27 kg/m2

In some cases, doctors may prescribe weight-loss medications to help control appetite or fat absorption. Medication use must be closely supervised by physicians and combined with lifestyle modifications to ensure safe and sustainable outcomes. Medication alone without behavioral changes is not recommended.

3. Bariatric surgery
Suitable for

• Individuals with BMI ≥ 32.5 kg/m2 and comorbidities
• Or those with BMI ≥ 37.5 kg/m2

Bariatric surgery is an option for those with severe obesity or multiple comorbid conditions such as type 2 diabetes. This treatment helps reduce weight and balances hormones related to metabolism. However, patients require long-term follow-up and concurrent lifestyle adjustments to optimize treatment efficacy.

Preventing overweight

Prevention starts with regular health monitoring and long-term lifestyle adjustments. Key strategies include:

• Regular health check-ups and BMI assessments to evaluate risk and plan appropriate care
• Promoting healthy eating behaviors from childhood to build a strong health foundation
• Increasing regular physical activity and movement in daily life
• Creating health-supportive environments at home, school, and in society

Overweight and obesity are not just about body shape or appearance but are chronic diseases affecting all health dimensions. Understanding causes, BMI criteria, risks, and proper medical care helps reduce complications and supports sustainable quality of life.

Information provided by : Dr. Arthit Weerabenjapol (W.27104), Endocrinologist and Metabolism SpecialistSamitivej Hospital