Is Obesity Genetic, and Can Bariatric Surgery Help

Genetic Obesity

There is a particular frustration we see in clinic, and it is different from simple disappointment with dieting.

It is the frustration of someone who has watched obesity move through their family for years.

A mother who developed type 2 diabetes in her forties.
A father who struggled with weight and heart disease.
Siblings who are now facing the same pattern.

When that history is there, weight gain does not feel random. It feels inherited.

And many patients quietly ask the same question.

If this is in my genes, what chance do I really have?

The Role of Genetics in Obesity

Obesity is not simply the result of eating too much or moving too little. Modern research is clear that body weight is strongly influenced by biology. In fact, genetic factors can account for a significant proportion of a person’s tendency to gain weight.

Certain inherited traits affect how the brain regulates hunger and fullness. Some people feel satisfied quickly after a meal. Others feel persistent hunger even when they have eaten adequately. Some individuals burn energy more efficiently. Others store energy more readily.

When obesity runs in families, it is often because these biological signals are shared.

This is why two people can follow similar diets and exercise routines, yet experience very different results. One may lose weight steadily. The other may struggle constantly, losing and regaining weight despite genuine effort.

It is not a character flaw. It is physiology.

Why Weight Regain Is So Common

For patients with hereditary obesity, the body often defends its weight very aggressively.

When weight is lost through calorie restriction alone, the brain responds by increasing hunger hormones and reducing metabolic rate. The body interprets weight loss as a threat. It works to restore what has been lost.

If you are genetically predisposed, that response can be stronger and longer lasting.

This is why so many people describe years of dieting followed by regain. Over time, the cycle becomes exhausting. Confidence drops. Shame creeps in. And yet the underlying biology has never truly been addressed.

The Link With Diabetes and Other Conditions

Genetic obesity rarely exists in isolation. It is frequently associated with:

  • Type 2 diabete
  • High blood pressure
  • Sleep apnoea
  • Fatty liver disease
  • Cardiovascular risk

In Ireland, we are seeing younger patients developing metabolic disease earlier than previous generations. A strong family history of diabetes or heart disease should not be ignored.

Obesity is not simply about weight. It is about long-term health risk.

Where Do Medications Like Ozempic and Mounjaro Fit

Treatments such as Ozempic and Mounjaro have changed how we approach obesity management. These medications act on gut hormones that regulate appetite and blood sugar. For many patients, they reduce constant hunger and make portion control achievable for the first time.

For individuals with moderate obesity, particularly those with early type 2 diabetes, these treatments can be very effective. They can reduce weight, improve HbA1c, and lower cardiovascular risk.

But for patients with severe obesity — particularly BMI over 40 or over 35 with significant medical complications — medication alone may not provide enough metabolic change to reverse established disease.

That does not mean medication has failed. It simply means the severity of the condition may require a more powerful intervention.

How Bariatric Surgery Addresses the Underlying Biology

Bariatric surgery, including gastric sleeve, gastric bypass and SADI-S, works at a deeper hormonal level.

It changes the communication between the gut and the brain. Hunger signals are reduced. Satiety improves. Insulin sensitivity increases. In many cases, blood sugar levels normalise rapidly after surgery, even before significant weight loss occurs.

For patients with hereditary obesity, this hormonal shift can counteract the biological drivers that have made weight control so difficult.

This is why bariatric surgery remains the most effective treatment for severe obesity and obesity-related type 2 diabetes. Long-term studies show sustained weight loss, high rates of diabetes remission and meaningful reductions in cardiovascular risk.

In Ireland and the UK, bariatric surgery is recognised as a medically necessary treatment for appropriate patients — not a cosmetic procedure.

Breaking a Pattern That Feels Inevitable

One of the most powerful moments in consultation is when a patient realises that their story does not have to follow the same path as their parents’.

If a parent required insulin in their fifties, that does not mean the same outcome is unavoidable.

If heart disease developed early in one generation, intervention can change the risk in the next.

Treating obesity effectively is not only about today. It is about reducing the likelihood of kidney disease, stroke, heart attack and mobility loss in the years ahead.

When obesity is genetic, early and appropriate treatment matters even more.

So Can Bariatric Surgery Help If Obesity Is Genetic

Yes. It can.

It does not erase your genes. But it can significantly reduce their impact.

For patients with severe or complex obesity, particularly those with a strong family history of metabolic disease, bariatric surgery offers the most durable improvement in weight, diabetes control and overall health risk.

The decision is never rushed. Assessment is careful. Medical treatment, including weight loss injections, may still have a role before or after surgery.

The goal is not simply weight reduction. The goal is long-term metabolic health.

You Are Not Alone In This

If obesity runs in your family and you feel that you have tried everything, it is important to understand that your experience is valid.

You may not lack discipline. You may be living with a chronic, genetically influenced disease that requires medical and possibly surgical care.

At Blackrock WeightCare, based at the Blackrock Clinic, we provide comprehensive obesity treatment including medical weight management and advanced bariatric surgery. Each patient is assessed individually, with careful consideration of family history, metabolic health and long-term goals.

If you would like to explore your options, you can begin by filling out a form on our website here or speak directly with our team on 01 255 2479.

Your Health. We Care.

Dr Eddy Ferrufino Rivera

Consultant in Respiratory and Sleep Medicine

Dr Eddy Ferrufino Rivera is a Consultant in Respiratory and Sleep Medicine with specialist experience in sleep-related breathing disorders, respiratory medicine and conditions commonly associated with obesity.

He has been practising in Ireland since 2015, working across both public and private hospitals. He completed his specialist training in Respiratory Medicine in Spain in 2013 and later obtained a Master’s Degree in Clinical Research and an International Master’s Degree in Sleep Medicine.

At Blackrock WeightCare, Dr Ferrufino supports patients with respiratory and sleep-related concerns, including obstructive sleep apnoea, obesity-associated hypoventilation and sleep disorders linked with conditions such as COPD, asthma and interstitial lung disease. He also facilitates sleep studies for patients where further assessment is needed as part of their bariatric care pathway.

Dr Ferrufino has experience in managing respiratory, cardiovascular and metabolic conditions associated with sleep pathology. He is an Associate Professor at University College Dublin and a member of the Irish Thoracic Society, the Royal College of Physicians of Ireland and the European Respiratory Society.

Emer O’Driscoll

Senior Dietitian

Emer O’Driscoll holds an MSc in Nutrition and Dietetics from the University of Ulster, Coleraine (2014). Emer has experience in clinical and outpatient settings, in particular, her passions are intuitive eating, counselling, and weight management. Emer is actively involved in the support of patients before and after weight loss surgery. She recognises the importance of consistent follow-up care with a dietitian through your pre and post-surgical journey. 

She holds a certificate in Motivational Interviewing from the National Institute for Preventive Cardiology (NIPC) and is a Certified Intuitive Eating counsellor. Emer developed and leads the SUCCEED Programme. She is a member of the Irish Nutrition & Dietetic Institute (INDI) and a CORU registered dietitian.

David Johnston

Senior Dietitian

David Johnston is a Senior Dietitian at Blackrock WeightCare. He holds a BSc in Human Nutrition and Dietetics from Trinity College Dublin and TU Dublin, and has completed additional training in behaviour change skills and the delivery of evidence-based obesity management.

David has worked in rehabilitation and integrated care services in both Ireland and Australia, supporting patients living with obesity, diabetes and other long-term health conditions. Chronic disease management has been a key area of interest throughout his career, and he understands the importance of a multidisciplinary approach when supporting people with obesity.

As part of the Blackrock WeightCare team, David provides education and follow-up care for patients before and after surgery. He helps patients prepare for surgery, supports them as they adjust to changes in eating and drinking afterwards, and works with them to build sustainable habits that support long-term health and weight management.

David is a CORU registered dietitian and a member of the Irish Nutrition and Dietetic Institute (INDI). His approach is practical and patient-centred, with a focus on helping patients better understand their nutrition and managing it in a way that works for them.

Niamh Forster

Senior Dietitian

Niamh Forster is a Senior Dietitian at Blackrock WeightCare, with 6 years of experience working with people living with obesity and supporting them with practical nutrition and lifestyle advice. She has worked in both clinical and outpatient settings, including weight management, and has a particular interest in supporting patients before and after bariatric surgery.

Niamh holds a BSc in Human Nutrition and an MSc in Clinical Nutrition and Dietetics from University College Dublin, completed in 2020. She has also completed further training in Behaviour Change, Intuitive Eating Counselling and Nutrition for PCOS.

She is a CORU registered dietitian and a member of the Irish Nutrition and Dietetic Institute (INDI).

As part of the Blackrock WeightCare team, Niamh supports patients in making sense of the dietary changes that come with bariatric surgery and helps them build habits that are realistic, manageable and suited to everyday life. Her approach is practical, evidence-based and centred around the individual, with a strong focus on supporting patients in a way that feels steady, respectful and achievable.

Nikki O’Toole

Bariatric CNS

Nikki O’Toole is a Bariatric Candidate CNS at Blackrock WeightCare, with over 18 years of nursing experience and a strong background in surgical nursing. She has worked in Blackrock Clinic for more than 10 years, caring for bariatric patients at ward level and now supporting patients throughout their journey before and after surgery.

Nikki holds a BSc Degree in Nursing and has recently completed a course in An Integrated Approach to Cardiometabolic Chronic Disease. In her role, Nikki provides education, preparation and ongoing support to patients at each stage of their journey. She helps patients feel informed and ready for surgery, and continues to support them after their procedure, both during their hospital stay and long after they go home. She understands how important it is for patients to feel reassured and know that support is always there when they need it.

Nikki gets great fulfilment in being part of transformation for patients and their families. She is committed to helping each patient feel cared for and confident throughout their time with Blackrock WeightCare.

Susan Healy

Bariatric CNS

Susan Healy is a Bariatric Clinical Nurse Specialist (CNS) at Blackrock WeightCare, with more than 20 years of nursing experience and a long-standing specialist interest in bariatric care. She first began working with bariatric patients in Australia almost 19 years ago and has been caring for bariatric patients in Blackrock Clinic for the past 10 years. She became a Bariatric CNS in June 2024.

Susan holds a BSc Degree in Nursing and is a Registered Nurse (RN) and Certified Bariatric Nurse (CBN) through the American Society for Metabolic and Bariatric Surgery (ASMBS). She is also a member of BOMSS, the British Obesity and Metabolic Surgery Society.

In her role, Susan supports patients right through their bariatric journey, both physically and emotionally, with a strong focus on education, reassurance and ongoing care. She is a steady point of contact before and after surgery, helping patients feel informed, prepared and well supported. Susan is passionate about providing patient-centred care and believes that people should be met with compassion and respect at all times. She takes great satisfaction in seeing the positive difference bariatric surgery can make and is committed to making sure each person feels listened to and supported throughout their journey.

Dr Matilde Mijares Zamuner

Consultant Endocrinologist and Diabetologist

Dr Matilde Mijares Zamuner is a Consultant Endocrinologist and Diabetologist at Blackrock WeightCare, with a particular interest in obesity, diabetes and the medical management of weight-related conditions. She graduated from medical school at the Central University of Venezuela in Caracas and completed her Higher Specialist Training in Endocrinology, Diabetes and Nutrition at Alicante University Hospital in Spain in 2013. She also completed a Master’s Degree in Clinical Research in Spain.

During her specialist training in Spain, she gained extensive experience in the management of metabolic conditions, including obesity and related conditions such as type 2 diabetes, high blood pressure and high cholesterol. She moved to Ireland in 2014 and completed a research fellowship in diabetes at the Mater Misericordiae University Hospital. 

As part of the Blackrock WeightCare team, Dr Mijares Zamuner supports patients by assessing hormonal, metabolic and nutritional factors that may be contributing to weight gain, including conditions such as PCOS and thyroid disease. She also works closely with patients before and after bariatric surgery and is involved in the medical treatment of obesity, including prescribed medication where appropriate.

Dr Mijares Zamuner is a member of the Irish Endocrine Society, the Spanish Endocrine and Diabetes Society, the European Society of Endocrinology and the Royal College of Physicians of Ireland. Her approach is centred on helping patients understand obesity as a chronic disease and supporting them in a clear and compassionate way to improve their long-term health and quality of life.

Achille Mastrosimone

Consultant Upper Gastrointestinal Surgeon and Bariatric Endoscopist

Achille Mastrosimone is a Consultant General and Upper Gastrointestinal Surgeon with a specialist interest in upper gastrointestinal surgery, diagnostic and therapeutic endoscopy, and bariatric and metabolic surgery. He works across Connolly Hospital, Hermitage Clinic and Blackrock Clinic, and is also an Honorary Clinical Senior Lecturer at RCSI University of Medicine and Health Sciences.

He holds an MD, a PhD in Clinical and Molecular Oncology, a Professional Diploma in Clinical Leadership from RCSI, and a Master in Bariatric and Metabolic Surgery from Gemelli Hospital, Rome.

As part of the Blackrock WeightCare team, he supports patients through pre-operative endoscopic assessment and post-operative endoscopic follow-up. 

Excitingly, Achille also brings expertise in endobariatric procedures, including TORe (Transoral Outlet Reduction), to help manage post-bypass weight regain and dumping syndrome.

Achille is registered on the Irish Medical Council Specialist Register in General Surgery and is a member of IFSO (International Federation for the Surgery of Obesity and Metabolic Disorders), ESGE (European Society of Gastrointestinal Endoscopy), ISDE (International Society for Diseases of the Esophagus) and EAES (European Association for Endoscopic Surgery).

His approach is centred on giving patients clear, compassionate and personalised support, helping them feel informed, reassured and well cared for before and after endoscopy.

Dr Finian Fallon

Psychologist

Dr Finian Fallon provides psychological support and assessments for patients seeking bariatric surgery at Blackrock WeightCare. He works closely with bariatric teams in Ireland and has a strong interest in supporting patients as they prepare for surgery and adjust to the changes that come with it.

Finian has contributed to research and published work in the area of obesity, and was previously a Research Fellow at St Vincent’s University Hospital, where he provided group support for people living with obesity. He has also worked as Dean of Psychology at a private college in Dublin, where he developed education programmes in areas including CBT, addiction and traumatology.

His academic work has included External Examinerships and supporting PhD students in their development. He has also presented at the SCOPE School on Obesity, an internationally recognised training programme in obesity led by experts in the field.

Finian has a particular interest in the psychological impact of obesity, including the effect of stigma and self-stigma on people’s lives. He is also very aware of the role trauma can play for some patients living with obesity. His research includes a widely reported study on trauma and wellbeing among more than 2,000 members of An Garda Síochána.

His approach is thoughtful, respectful and compassionate, with a strong focus on helping patients feel understood, supported and well prepared throughout their journey.

Professor John McDermott

Consultant Endocrinologist

Professor John McDermott is Consultant Endocrinologist at the Hermitage Medical Clinic. Working closely with Mr Robb and the team at Blackrock WeightCare, he supports patients through their weight loss journey with a focus on metabolic health, endocrine assessment and long-term aftercare. He plays an important role in guiding patients before and after bariatric surgery, and supporting them as they adjust to the hormonal, metabolic and lifestyle changes that follow treatment.

Professor McDermott graduated from the University of Galway with first-class honours and the gold medal for first place in medicine. Following his specialist training, he was appointed as a Consultant Endocrinologist in 2007. He has extensive experience in endocrinology, diabetes and general internal medicine, and a strong commitment to clinical research and medical education.

Dr Conor Woods

Endocrinologist & Bariatric Physician

Dr Conor Woods is an Endocrinologist and Bariatric Physician at Blackrock WeightCare, with specialist interests in obesity medicine, endocrinology and diabetes. He completed his undergraduate medical training at RCSI and his Higher Specialist Training in Endocrinology in Ireland. He also holds a PhD from UCD in steroid metabolism and obesity, and completed a fellowship in Oxford.

Dr Woods supports patients with the medical assessment and management of obesity and related metabolic conditions. As part of the multidisciplinary team, he helps ensure patients are well informed, appropriately assessed and supported throughout their care.

Barkha Jain

Digital Marketing Manager and Web Developer

Barkha Jain is the Digital Marketing Manager at Blackrock WeightCare, with over 20 years of experience in advertising, marketing and business development. She holds a Bachelor’s degree in Journalism and Mass Communication from DAVV University, India, and a Master’s degree in Digital Marketing from UCD, Ireland.

For the past 10 years, she has specialised in healthcare marketing, working with surgeons across bariatric surgery, plastic surgery, respiratory medicine, IVF and orthopaedics. Before moving to Ireland, she founded a digital marketing agency in India in 2016 and worked with healthcare clients across the country, including spending 8 years with Mohak Bariatrics, an internationally renowned bariatric service in Indore, India. Barkha has facilitated a collaboration between Mohak Bariatrics and Blackrock WeightCare – a connection we are proud to have established.

Her work is rooted in a genuine belief that healthcare communication should do more than promote services. It should bring clarity, build trust and help people make informed decisions for their health and wellbeing.

Susan Anderson

Patient Co-Ordinator

Susan Anderson is a Patient Co-Ordinator at Blackrock WeightCare and is often the first point of contact for patients enquiring about weight loss surgery. Susan speaks with patients by phone to guide them through the process, answer their questions and provide clear information about the process from first appointment, assessment for surgery and our dedicated follow up program of care. She follows up with detailed information on the next steps, helping patients feel informed from the outset.

Susan also attends clinics and values meeting patients in person, offering support as they move through different stages of treatment. She understands that reaching out about bariatric surgery can feel like a big step and how important it is for patients to be given time, information and reassurance to make the decision that is right for them.

With almost two decades of experience working in a hospital setting, Susan is committed to helping each patient feel comfortable, informed and well supported from their first contact with Blackrock WeightCare.

Lucy O’Shea

Patient Co-Ordinator

Lucy O’Shea is a Patient Co-Ordinator at Blackrock WeightCare, where she supports patients throughout all phases of their treatment – from bariatric surgery, to medical follow up with optimisation of health and weight and then also co-ordinating body contouring surgery for those patients who require this final phase.

Lucy helps guide patients through each stage of the process, from explaining what to expect and preparing them for consultations to providing support before and after surgery.

Working closely with the clinical team, Lucy ensures that patients feel informed, supported and reassured throughout their journey to better health. She understands that this can be a significant step, and Lucy is committed to making the experience as comfortable and straightforward as possible.

Lucy helps each patient feel heard, supported and at ease throughout their care with Blackrock WeightCare.

Maria Cray

Practice Manager

Maria Cray is the Practice Manager at Blackrock WeightCare, with over 20 years of experience managing busy private surgical clinics. Before joining the team, she spent two decades as Practice Manager for a consultant eye surgeon, where she ran a successful multi-staff practice and supported patients through every stage of their care.

She brings a calm, organised and caring approach to the role, with a great understanding of what patients need from specialist care. From coordinating appointments and referrals to helping manage surgical schedules, Maria plays a central role in ensuring that every patient’s experience is as smooth as possible.

WIth the whole team, Maria creates a welcoming and professional environment where patients feel supported, informed and genuinely cared for throughout their journey with Blackrock WeightCare.

Go Surgical Limited
Suite 9, Blackrock Clinic, Rock Road, Blackrock, Dublin, A94 E4X7