Obesity is a complex, chronic medical condition characterised by excess body fat that may negatively affect health. It is commonly assessed using Body Mass Index, which is calculated using a person’s height and weight.
In clinical terms:
- A BMI of 25 to 29.9 is classified as overweight
- A BMI of 30 or above is classified as obese
If you would like to understand your current BMI, you can use our BMI Calculator for an initial indication.
The NHS provides an overview of obesity and its health risks here:
https://www.nhs.uk/conditions/obesity/
Tonic is rated 5-star ‘Excellent’ on Trustpilot and provides structured, medically responsible care for people living with obesity across the UK.
Is Obesity a Disease?
Many global medical organisations, including the World Health Organization, recognise obesity as a chronic disease. It is influenced by a complex interaction of biological, environmental, psychological and social factors.
Classifying obesity as a disease helps reduce stigma and reinforces the need for structured medical support. It also acknowledges that obesity is not simply a matter of willpower.
By recognising obesity as a medical condition, healthcare professionals can develop personalised treatment plans that address underlying causes and long-term management.
What Health Risks Are Linked to Obesity?
Obesity is associated with an increased risk of:
- Type 2 diabetes
- Cardiovascular disease
- High blood pressure
- Stroke
- Sleep apnoea
- Joint disease such as osteoarthritis
- Certain cancers
It may also impact mental wellbeing, contributing to anxiety, low mood and reduced confidence.
NICE guidance outlines when intervention, including bariatric surgery, may be considered for people living with severe obesity (CG189):
https://www.nice.org.uk/guidance/cg189
What Causes Obesity?
Obesity is rarely caused by a single factor. Contributing influences can include:
- Genetics
- Hormonal and metabolic conditions
- Dietary patterns
- Low physical activity levels
- Environmental factors
- Certain medications
Because obesity often results from multiple interacting factors, treatment may require a multidisciplinary approach.
What Is Weight Loss Surgery?
Weight loss surgery, also known as bariatric surgery, is a medical treatment designed to support significant and sustained weight reduction in people living with severe obesity.
It is typically considered for individuals with:
- A BMI of 40 or above
- A BMI of 35 to 40 with serious obesity-related health conditions
- In some cases, type 2 diabetes at lower BMI thresholds
Bariatric surgery works by altering the digestive system to reduce food intake and, in some procedures, influence metabolic processes.
At Tonic, available Weight Loss procedures include:
Each procedure has different indications, benefits and considerations.
What Are the Potential Benefits?
Clinical studies show that bariatric surgery may support:
- Significant weight reduction
- Improved blood glucose control
- Reduced blood pressure
- Improvement in sleep apnoea
- Reduced joint discomfort
- Enhanced mobility
In some patients, type 2 diabetes may enter remission. However, results vary and ongoing monitoring remains essential.
Is Weight Loss Surgery Safe?
All surgery carries risk. Bariatric surgery is commonly performed using keyhole, or laparoscopic, techniques, which involve smaller incisions and may support shorter recovery times compared to open surgery.
Your surgeon will explain potential risks and benefits in detail during consultation so you can make an informed decision.
Common Questions After Surgery
Can I drink fizzy drinks after surgery?
Carbonated drinks are generally discouraged, particularly in the early stages of recovery. They may cause discomfort, bloating or irritation in a smaller, more sensitive stomach. Sugary fizzy drinks may also contribute to weight regain.
Your dietitian will guide you on safe reintroduction of foods and drinks.
When can I drive again?
Driving should only resume when you feel physically and mentally capable, and after discussion with your surgeon. The DVLA provides general guidance suggesting at least one week after laparoscopic surgery and longer after open surgery, depending on recovery.
Always follow individual medical advice before returning to driving.
Structured Aftercare Matters
Weight loss surgery is not a standalone event. Long-term outcomes depend on sustained engagement with follow-up care.
Tonic includes a structured 5-year aftercare programme. Years 1–2 include personalised 1-to-1 support from our team, psychotherapy, dietitian support, nurse support and fitness trainer support — alongside surgeon follow-up. Years 3–5 include ongoing telephone support from the aftercare team, with continued surgeon follow-up.
This approach supports nutritional monitoring, behavioural change and long-term health management.
If you are considering bariatric surgery, you can arrange a consultation via Contact Us to discuss your individual circumstances.
Tonic is rated 5-star ‘Excellent’ on Trustpilot and remains committed to quality-led, medically responsible care across the UK.
Sources
NHS – Obesity
https://www.nhs.uk/conditions/obesity/
NHS – Weight loss surgery
https://www.nhs.uk/conditions/weight-loss-surgery/
National Institute for Health and Care Excellence – Obesity: identification, assessment and management (CG189)
https://www.nice.org.uk/guidance/cg189
British Obesity and Metabolic Surgery Society – Patient information
https://www.bomss.org.uk/patients/
World Health Organization – Obesity and overweight
https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
