---

In February 2010 the Scottish Intercollegiate Guidelines Network (SIGN) published its guideline on Management of obesity.¹ This has been the first major review of all available evidence since the National Institute for Health and Clinical Excellence (NICE) published a comprehensive obesity guideline in 2006.² Since this document, there have been very few consensus guidelines or updates to reflect recent changes in practice. Is the new SIGN guideline a welcome addition?

One main focus of the SIGN guideline was the review of best practice based on the current available evidence, taking cost effectiveness out of the equation. There is an obvious argument for having a review that only examines what clinical management should involve and provide if cost is not an issue. A further welcome addition in the guideline is the incorporation of ‘good practice points’ that reflect the consensus opinion of specialists in this field—when current practice suggests a clear management option, but there is no evidence to support it.¹ In this way the guideline serves to be both a reference point for current evidence and also a consensus guideline on best practice when the evidence is lacking. This provides the practitioner with much more practical help than a simple literature review.

It is reassuring to find that 4 years after the publication of the NICE guideline, the new SIGN guideline reinforces most of the same advice that appeared in it.^1,2 There is once again clear and referenced advice on the key areas such as classification of weight using body mass index (BMI) and waist circumference, prevention, identification, assessment, and treatment in both adults and children.¹ However, there are some areas worthy of note and clarification to avoid potential confusion among practitioners and these are discussed below.

Assessment of obesity in children

It is important to highlight the fact that during assessment of obesity in children, the classification of overweight/obese has been based on the 91^st/98^th BMI centiles, respectively.³ There is in fact at least some evidence to support this, which is given in the guideline,¹ and this criteria has been used by the Royal College of Paediatrics and Child Health for some time. However, it has now been rendered unhelpful south of the Scottish border since the advent of the National Child Measurement Programme for England, in which the Department of Health (DH) insists on using the arbitrary 85^th/95^th classification.⁴

In practice it would have been better for the DH to have adopted the 91^st/98^th BMI centile criteria, especially as these are clearly marked on the child growth charts that all clinicians should be encouraged to use. However, I imagine that this classification is now too established to be altered, and is here to stay. This could obviously lead to confusion among patients and healthcare professionals, and there are issues relating to the compatibility of data if patients are accessing healthcare services in a different country within the UK.

Managing obesity and co-morbidities

One further point of note in the new SIGN guideline is with respect to the treatment of patients with a BMI >35 kg/m². There is an assumption that patients with a BMI >35 kg/m² are likely to have obesity related co-morbidities and that the focus of weight-loss interventions should be aimed at improving these co-morbidities,¹ with the implication that we should not just be reducing actual weight for the sake of it. This may be considered a welcome opinion as there has been long debate over how ‘simple obesity’, in the absence of co-morbidities, should be managed, and whether the same time and resources should be apportioned to this group of patients. However, how will this advice be interpreted?

For those GPs keen to manage obesity, they will see this as an opportunity to manage patients more aggressively if their BMI >35 kg/m² (aiming for the recommended 15%–20% or over 10 kg weight loss),¹ assuming that co-morbidities are present, even when currently not yet diagnosed. However those practitioners who have never been keen on managing obesity may interpret this advice as an opportunity not to offer any weight management services to a patient with a BMI >35 kg/m² if they have no proven co-morbidity, with the obvious potential argument that it then becomes no different to a cosmetic procedure. This would be extremely short-sighted on a number of levels, and I hope this scenario never arises.