Nutritional aspects of bariatric surgery
Too Lean a Service? Mary O’Kane
Clinical specialist dietitian Leeds Teaching Hospitals NHS Trust
BOMSS council member
Does surgery result in a better diet?
• Decreased intake of sweets and sugary drinks but tolerance increases with time, high intake of salty snack foods (Brolin et al 1994)
• Decrease in energy from protein and increase from sugar and alcohol, decrease in prepared meals and increase in sweet foods (Lindroos et al 1996)
• Patients may end up snacking more and eating less regular meals (grazing), poor intake of protein, vitamins and minerals, intakes of iron, zinc, vitamin D below requirements (Naslund et al 1998)
• 37% had resumed snacking 1 year after gastric bypass (Elkins at al 2005)
• Cravings for sweets results on significant less weight loss (Burgmer et al 2005)
Self reported post operative dietary compliance and weight loss after gastric bypass
Sarwer et al. SOARD 4 (2008) 640–646
Role of the dietitian
As a core member of the MDT:
• Initial assessment of diet, nutritional status and eating behaviours (and psycho-social factors)
• Advice and support on the appropriate diet
• Monitoring of micronutrient status
• Individualised nutritional supplementation, support and guidance to achieve long-term weight loss and weight maintenance
NICE CG43 Obesity 2006
NICE CG43 Obesity Bariatric surgery
All appropriate non-surgical measures have been tried but have failed to achieve or maintain adequate, clinically beneficial weight loss for at least 6 months
The person has been receiving or will receive intensive management in a specialist obesity service
The person commits to the need for long-term follow-up.
Too lean a Service? Dietetic input
Pre-referral
• No documented evidence of pre-referral dietetic input in 65% cases
Post-referral
• 22% patients not assessed by a dietitian prior to surgery
• 27% patients, no evidence of dietetic input prior to surgery
Adequacy of dietetic input pre-surgery
Too lean a service?
Adequate dietetic assessment /education for patient
Number of patients¹ (for those with evidence)
% for those with evidence
Number of patients (for all patients)
% for all patients
Yes 195 92.9 200 77.5
No 15 7.1 58 22.5
Subtotal 210 258
Insufficient data
27 123
Total 237 381
MDT meeting
Discharge summary Too Lean a Service?
Poor / unacceptable
• Diet information (10 patients)
• Emergency contact (9 patients)
Inappropriate discharge prescription
• Lack of vitamin supplements (10 patients)
• Inappropriate vitamin B12 (1 patient)
Follow-up Too lean a service
Follow-up clinics Number of hospitals (105)
Bariatric surgeon 95
Dietitian 86
Specialist nurse 58
Psychologist/ psychiatrist 24
Bariatric physician 21
Other 2
Types of follow-up clinic
72/102 hospitals gave early telephone follow-up
Dietary related problems following bariatric surgery
• Dehydration
• Nausea and vomiting
• Regurgitation
• Food intolerances
• Constipation
• Diarrhoea /steatorrhea
• Dumping syndrome
• Loss of appetite / Anorexia
• Fear of stretching the pouch
• Return of appetite
• Alopecia
Bariatric procedures, vitamins and minerals
Vitamin mineral deficiency / Surgery
Pre-surgery AGB Sleeve gastrectomy
RYGB BPD +/- DS
Thiamin Uncommon Uncommon Uncommon Uncommon Uncommon
B12 10-13% Uncommon Uncommon 12-33% Uncommon
Folate Uncommon Uncommon Uncommon Uncommon Uncommon
Iron 9-16% of women
Uncommon 20-49%
Vitamin A Uncommon Rare Rare Rare but can occur
50% at 1 year 70% at 4 years
Vitamin D 60-70% Common V. Common
Zinc Uncommon May occur Common
Protein Uncommon May occur May occur May occur May occur
Protein –energy malnutrition / protein malnutrition
• Food intolerance / Eating habits /Compliance
• Anorexia / loss of appetite
• Stricture / too tight a band
• Diarrhoea
• Requirements of BPD/ DS higher
Implications of “Too Lean a Service?”
• All patients being considered for bariatric surgery should receive dietary assessment and education prior to referral and definitely prior to surgery
• The dietitian is the key MDT member to undertake this assessment, education and provision of follow-up support
• Psychological assessment and support should be available
• Dietetic advice including vitamin and mineral supplements and discharge advice needs to be clearly documented
On-going work
• BOMSS training for dietitians and other healthcare professionals
• “Providing bariatric surgery” - the BOMSS Standards for Clinical Services & Guidance on Commissioning
• Clinical Reference Group on Morbid Obesity – comprehensive patient pathway
• Vitamins and minerals and pre- and post-surgery nutritional monitoring guidelines–work in progress