Degree Name

Doctor of Philosophy


School of Health Sciences, Faculty of Health and Behavioural Sciences


Obesity is one of the most common disorders encountered in clinical practice and has major public health implications. It is also one of the most difficult and frustrating disorders to manage successfully. The prevalence of overweight and obesity in Saudi Arabia is high and increasing over recent years. Management of obesity should be based on the best available scientific evidence. At present, there are no national clinical practice guidelines of use by dietitians and other health practitioners for the management of obesity. Since dietetics is a relatively new profession in Saudi Arabia there is little published data available in this area.

This thesis aimed to describe the current dietetic practices of obesity in Saudi Arabia and to develop a draft set of national clinical practice guidelines for obesity management. The present thesis includes three main projects. Based on the outcomes of these projects, a draft of evidence-based practice guidelines for the nutritional management of obesity in Saudi Arabia was prepared.

The first project (Chapter 3) involved dietitians to investigate the context and better understand the range of current practices in obesity management in Saudi Arabia, demand for and level of service, and barriers to obesity management. Analysis of the study showed that Saudi Arabian dietetic practice for the management of obesity does incorporate most practice recommendations, but some specific elements are rarely used. The most common assessment approaches were assessment of BMI, exercise habits and weight history while the most common strategies for obesity management were dietary total fat reduction and increased incidental daily activity. The major barriers for establishment of a weight management clinic were inadequate resources and administration and referral issues. None of the participants used local obesity guidelines but 61% of participants relied on international guidelines.

The second project included two studies focused on the validity of the most important practical tools used for the classification of obesity (Chapter 4) and the assessment of energy requirements (Chapter 5) since research has been lacking in this area in the Saudi population. The first study examined the use of different BMI cut-off points for obesity classification. Results indicated that the diagnostic usefulness of BMI alone in defining obesity is limited in the Saudi adult population, for both men and women. It seems likely that limiting management of obesity only to those individuals with a BMI ≥ 30, as defined by the WHO, may mean that many Saudis at risk of serious co-morbidities could be missing necessary interventions. The second study assessed the accuracy of prediction equations and a popular hand-held calorimeter (BodyGem) for assessment of resting energy expenditure (REE). Based on the findings of this study it was concluded that the Harris-Benedict, Schofield and WHO equations tend to predict REE more accurately than the BodyGem device. However, their accuracy was not clinically acceptable on an individual level. Therefore, the value of the use of both BodyGem devices and predictive equations is still uncertain for Saudi population and more research is needed in this area.

The third project (Chapter 6) focused on the development of draft clinical practice guidelines, based on a review of existing international guidelines, supplemented with systematic literature reviews, and refined through the use of consultation workshops and Delphi technique consultations with Saudi experts and practitioners. Findings from the systematic mini reviews provided low to medium level evidence for the use of some novel dietary interventions such as the high intake of calcium, PUFA or fiber to assist with weight loss or maintenance. There was also similar evidence for the use of a low glycemic index diet. Higher eating frequency, not exceeding 6 meals per day, may also help in weight reduction. Regular breakfast intake also appears to be associated with lower body weight. Consultations workshops and Delphi consultations indicated that there are cultural differences between Saudi Arabian population and other Western populations. Therefore, specific consensus statements were developed to cover practice areas such as behavioral modifications, dietary counselling strategies, physical activity and obesity management in Ramadan.

In summary, this thesis has provided clinical practice guidelines for obesity management in Saudi Arabia. The application of these guidelines will improve nutritional management of obesity and enable dietitians and other health professionals to use approaches based on the best available evidence.

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