Obesity surgery
Bariatric surgery and the importance of nutrition The prevalence of obesity in the UK continues to rise and is associated with many health issues such as diabetes, metabolic syndrome, obstructive sleep apnoea and osteoarthritis. The focus of treatment is on dietary, activity and lifestyle changes; however, for those with severe and complex obesity, bariatric surgery may be a treatment option. Mary O’Kane Consultant Dietitian (Adult Obesity), Leeds Teaching Hospitals NHS Trust
The main bariatric surgical procedures are the gastric band, gastric bypass and sleeve gastrectomy (Figures 1-4). The duodenal switch is performed less frequently. All procedures affect the dietary intake and the gastric bypass, sleeve gastrectomy and duodenal switch affect absorption to varying degrees. For patients with severe and complex obesity, bariatric surgery is an additional tool which will aid weight loss and result in metabolic improvements. The National and Bariatric Surgery Registry (NBSR) reported that the average weight loss at one year after surgery was 58.4% excess weight (1). Two years after surgery, 65 percent of patients with Type 2 diabetes were able to stop their medication. Eligibility for bariatric surgery
Mary is a Consultant dietitian supporting patients with severe and complex obesity in the medical and surgical obesity pathways. Member of BOMSS council. Member of NICE clinical guidelines Obesity 2006 and 2014.
To be eligible for bariatric surgery, a number of criteria must be met (National Institute for Health and Care Excellence (NICE) 2014 (Table 1) (2). In the NHS, patients are referred in for surgery by the Tier 3 medical obesity services. The patient will undergo a comprehensive multidisciplinary team (MDT) assessment which includes exploring the benefits and risks of surgery. The dietitian plays a key role in the assessment of the patient’s understanding of bariatric surgery and ability to comply with postoperative dietary advice and cope with the emotional impact. Not all patients will go forward for surgery as the team may consider some patients to be too high risk or recommend further investigation and treatment. Other patients will de-
cide that surgery is not for them or that the timing is not appropriate. Impact on diet and nutrition
All of the surgical procedures impact on dietary and nutritional intake (Table 2). The gastric bypass, sleeve gastrectomy and duodenal switch procedures affect the absorption of micro and macronutrients to varying degrees. The specialist bariatric dietitian plays an important role is supporting patients through their weight loss journeys and ensuring nutritional needs are met. Following surgery, all patients are advised to progress their diet slowly, beginning with a liquid diet before moving onto blended food, soft food and then foods of a more normal texture. They must learn to chew their food well, eat slowly and avoid having drinks with meals. Certain textures of food are difficult to manage for example, roast or grilled meats and poultry, bread, rice and pasta. These can be replaced with casseroled meats and poultry, crisp breads, crackers and toasted bread and potatoes. The initial portion sizes are very small, but will increase over time. Patients need support to make the dietary changes including the planning of meals. Some patients may struggle to follow the advice. If they try foods of an inappropriate texture or do not chew their food, they may find it becomes lodged in the gastric pouch causing pain and discomfort. This may then lead to food avoidance /phobias or replacement with soft high calorie foods NHDmag.com July 2015 - Issue 106
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