Management of obesity

In reply: We agree with McHenry and colleagues that, until very recently, surgery was the only effective treatment for morbid obesity. However, the development of effective pharmacotherapy that targets the underlying cause — increased hunger — may well change this situation, as evidenced by the effect of leptin treatment in leptin-deficient children.1 In the not-too-distant future, a medical alternative may be possible.

The issue of the relative merits of surgery to insert a foreign body (gastric band) or permanently alter the anatomy of the gastrointestinal tract versus lifelong pharmacotherapy will need to be considered. However, economic as well as health issues may be important, and, as McHenry and colleagues suggest, may still favour surgery as the preferred therapy.

We thank Davies for bringing to our attention Campos’ book The obesity myth, in which he claims that overweight individuals are in fact healthier than those of normal weight.2 While many of the book’s other claims can be challenged (such as the statements that the prevalence of type 2 diabetes is not rising in the United States, and that bald men have higher testosterone levels), the fact that there is no simple linear relationship between body mass index (BMI) and illness is correct. Sex, race and fat distribution can all influence the relationship. Moderately overweight women with gynoid (hip and thigh) fat are not at increased risk of illness.3 In contrast, South Asian people have an increased risk of developing diabetes at lower BMI values than people of European background. We agree with Davies that maintaining fitness through regular exercise is very important in minimising the health consequences of obesity.

Tran raises the issue of whether it is useful to measure insulin levels in children. It is not unreasonable to assume that insulin levels are raised in most obese children, but this is not always the case. The National Health and Medical Research Council clinical practice guidelines for management of overweight and obesity in children and adolescents state that: “Fasting insulin and glucose should be considered in obese children or adolescents, particularly those with a family history of type 2 diabetes, those with acanthosis nigricans and those from certain ethnic backgrounds”.4 In the presence of insulin resistance, serum glucose level remains normal because of high insulin levels. Thus, glycaemia cannot be used to monitor improvement in insulin sensitivity.