Introduction

What is Obesity?

The incidence of overweight and obesity in our society is on the rise and is due to a complex interaction of human behaviour, environmental and genetic factors.

In order to know wether one has overweight or obesity, the Body Mass Index or BMI should be determined. In addition, this chapter provides an overview of a number of conditions or diseases that can be associated with obesity.

Body Mass Index (BMI)

To find out whether or not you are overweight or obese, you first need to calculate your 'Body Mass Index' or BMI:

BMI (kg/m2) = weight (kg)/ (height (m))2

A person with a BMI between 25 and 29.9 (kg/m2) is considered as overweight. A person with a BMI of 30 kg/m2 or more is considered obese. Obesity itself is further subdivided into class I (BMI 30 -34.9 kg/m2), class II (BMI 35.0 – 39.9 kg/m2) and class III or extreme obesity (BMI ≥ 40 kg/m2).

How prevalent is obesity?

Based on the latest official statistics from the UK Government's Office for Health Improvement and Disparities and the NHS:

In 2021/22, 64.2% of adults in England were classified as overweight or obese, with 25.9% falling into the obese category. This marks a significant increase from the mid-1990s, when 52.9% of adults were overweight or obese, and only 15% were obese.

The figures are particularly concerning across the devolved nations, with Scotland reporting 66% of adults as overweight or obese, Wales at 61%, and Northern Ireland at 65% according to their respective national health surveys.

The childhood obesity crisis in the UK is equally alarming. NHS Digital data shows that in 2021/22, 23.4% of Year 6 children (aged 10-11) were classified as obese, and a further 14.3% as overweight. This represents a worrying increase from a decade ago.

The UK Health Security Agency projects that if current trends continue, by 2030 approximately 70% of the UK population could be overweight or obese. This forecast aligns with broader global predictions from the World Health Organisation, which suggests similar patterns worldwide, though the UK's rates remain among the highest in Europe.

These statistics specifically reflect measurements using the NHS BMI classification system, where a BMI of 25-29.9 is considered overweight, and 30 or above is classified as obese.

Understanding the causes of obesity

Whilst obesity is increasingly prevalent in modern British society, there remains significant stigma towards individuals with obesity, who often face unfair accusations of being 'lazy' or 'lacking willpower'. However, current scientific evidence demonstrates that obesity is a complex medical condition influenced by multiple factors beyond individual control.

Genetic Predisposition

Research indicates that genetic factors play a substantial role in determining an individual's likelihood of developing obesity. Studies have shown that children whose parents have obesity are significantly more likely to develop the condition themselves. The NHS estimates that inherited genes can affect how efficiently our bodies convert food into energy, where we store fat, and how we regulate our appetite.

Behavioural Factors

Several behavioural aspects influence weight management:

• Eating patterns and relationship with food

• Food choices and portion control

• Response to stress and emotional eating

• Sleep quality and duration, which recent studies have shown significantly impacts weight regulation

• Physical activity levels and exercise habits

Environmental Influences

Modern British society has created what health experts term an 'obesogenic environment':

Food Environment

The UK food landscape has transformed dramatically over recent decades, characterised by:

• Increased availability of ultra-processed foods

• Greater portion sizes in restaurants and packaged foods

• Heavy marketing of high-calorie, low-nutrient foods

• Proliferation of fast-food outlets, particularly in deprived areas

• Higher consumption of sugary drinks and snacks

Lifestyle Changes

Contemporary British lifestyle factors contributing to obesity include:

• Increased sedentary occupations

• Reduced active travel (walking/cycling)

• Greater reliance on cars and public transport

• More screen time and less physical activity

• Longer working hours affecting meal preparation time

The Interaction of Factors

According to Public Health England and leading obesity researchers, genetic factors account for approximately 70% of an individual's predisposition to obesity, whilst environmental and behavioural factors contribute the remaining 30%. However, these proportions can vary significantly between individuals, highlighting the need for personalised approaches to weight management.

This complex interplay of factors underscores why simplistic approaches to obesity prevention and treatment often prove ineffective, and why comprehensive, evidence-based strategies addressing multiple contributing factors are essential.

Health Risks of Obesity

Life Expectancy Impact

Obesity significantly reduces life expectancy. Research shows obese men with type 2 diabetes at age 30 live approximately 10 years less than their healthy-weight counterparts.

Key Medical Risks

Type 2 Diabetes

• Five times higher risk in obese individuals

• Causes insulin resistance and elevated blood sugar

• Increases cardiovascular disease risk

Heart and Circulation

Triple risk of cardiovascular problems

Common issues include:

• High blood pressure

• Atherosclerosis

• Abnormal cholesterol levels

• Higher stroke risk

Fertility Problems

• Strong link to PCOS in women

• Half of PCOS patients are overweight/obese

• Reduced ovulation in obese women with PCOS

Other Physical Health Risks

• Sleep apnoea

• Liver disease

• Joint problems

• Various cancers

• Respiratory issues

• Digestive disorders

• Gallbladder disease

Mental Health Impact

Psychological Effects

• Increased anxiety and depression

• Lower self-esteem

• Social stigma

• Workplace discrimination

• Healthcare bias

Contributing Factors

• Hormonal changes

• Physical limitations

• Social prejudice

• Failed weight loss attempts

These combined factors often create a cycle where mental health challenges can lead to further weight gain.

Source: Based on NHS and UK Health Security Agency data

Treatment Options

Your Health Matters

Stay Informed, Stay Healthy

At EliteSurgix, we believe in empowering our patients with knowledge. Explore our detailed information on various gastroenterology conditions to better understand your health and wellbeing. Learn about symptoms, causes, and when to seek medical advice. Click on each condition to find comprehensive descriptions and personalized treatment options.

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