Bariatric and Obesity Surgery

Bariatric and Obesity Surgery

Main Address

  • Outpatient consultations
    Clinic 4A and 4B
    Outpatient department
    Whittington Hospital
  • Appointments: 020 7288 5511 / 5512
The bariatric service at the Whittington Hospital is known as the North London Obesity Surgery Service (or NLOSS). The Whittington Hospital has been providing bariatric surgery since 1998 and is one of the most established providers of such services in the UK.
At NLOSS, we undertake Gastric banding, Roux-en-Y bypass (gastric bypass), Single Anastomosis Gastric Bypass and Sleeve gastrectomy as well as revision surgeries.  All operations are performed laparoscopically (keyhole surgery), which will help you to get up and around and back to normal very soon after surgery.
One of the mainstays of the NLOSS is our multidisciplinary team. Each team member has his or her own role and all together we ensure you are fully informed about weight loss surgery and that your operation is performed in the safest possible environment. Your safety is our first priority.

Opening Hours

Monday to Friday
9am - 5pm


Referrals can be made via your GP.

Range of services

  • Gastric banding (LAGB)
  • Roux-en-Y Gastric Bypass (LRYGB)
  • Single Anastomosis Gastric Bypass (SAGB)
  • Sleeve gastrectomy (LSG)
Psychological (prior to surgery)
  • Eating Disorder Evaluation
  • Self-help group for correction of eating disorders such as binge eating
  • Cognitive behaviour therapy (CBT)

General Enquiries

0207 288 5372 (Bariatric Patient Pathway Co-ordinator)


020 7288 3071 or 07769 926527


If patient's do not attend appointments, they may be discharged back to their GP. This will allow other patients the opportunity to  undergo treatment.

Bariatric Surgery Pathway Explained

Initial Appointment
At your initial assessment you will meet one of our members of the staff, this could be a surgeon, a registrar a specialist nurse or a dietitian.
At your initial appointment, you will be asked a great number of questions regarding your past medical, surgical history, weight management history, psychological wellbeing, eating behaviour and social circumstances.

Your clinician will order tests and investigations to help determine your suitability for surgery.  Most commonly ordered investigations are:

  • Blood Test
  • Oesophago-gastro-duodenoscopy (OGD)
  • Eating Disorder Assessment
  • Cognitive Behaviour Therapy (CBT)
  • Echocardiogram (ECHO) Electrocardiograph (ECG)
  • Sleep Study
  • Attend a virtual education session
  • Other necessary investigations or treatment – based on previous medical history

Having undergone your first assessment does not guarantee that you are a suitable candidate for bariatric surgery; suitability will be determined after the second appointment. 

Follow-up Appointment
After the initial assessment you will be invited to see your surgeon for the second time  approximately 4 – 6 moths later to review the result of the above investigation, which will determine if you are a suitable candidate for bariatric surgery.

After your second appointment the surgeon will do one of three things:

  1. List you for surgery
  2. Request further investigations
  3. Discharge you – if you are found to be unsuitable for surgery.

Further Information

Lorna Antoine
Bariatric MDT Co-ordinator (020 7288 5226)
Naiara Fernandez-Munoz
Bariatric and Upper GI Advanced Nurse Practitioner (020 7288 3071)

Eirini Aritzi
Bariatric and Upper GI Nurse Practitioner (020 7288 3071)

Melisa Ilkgoren
Specialist Bariatric Dietitian (020 7288 5989)
Katarina Burton
Specialist Bariatric Dietitian (020 7288 5989) 

Key staff

Mr Ali Alhamdani

Mr Ali Alhamdani


Mr Chetan Parmar

Mr Chetan Parmar

Consultant in Upper Gastrointestinal and Bariatric Surgery

Pratik Sufi

Mr Pratik Sufi

Consultant in Upper Gastrointestinal and Laparoscopic Surgery

Last updated23 Apr 2024
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