The Management of Obesity and Related Disorders (PDF)

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Much of the condemnation of current dietary treatment strategies is based on the results of clinical trials and hospital-based programmes. Patients who participate in these represent a very small percentage of the total obese population and tend to be the more challenging patients, often presenting with significant psychological problems and a higher incidence of ‘binge eating’ disorder, factors known to affect treatment outcome detrimentally.

It is therefore inappropriate to consider the .ndings from clinical trials and hospital-based programmes as being representative of the likely outcome of intervention in the general overweight and obese population.
Evaluating the long-term effect of dietary intervention is essential if we are to achieve improved practice and treatment outcomes. It has been suggested that this should be a research priority in the primary care setting. Nevertheless, careful and appropriate interpretation of .ndings is paramount.

Interpretation of the ‘diets don’t work’ message is also influenced by the definition of the term ‘diet’; it is important to make the distinction between medically approved healthy diets with a scientific rationale and the plethora of popular weight loss diets, which often make unrealistic and scientifically unsupported claims.

Energy balance

It is well known that the body’s fat and energy stores are determined by the balance between energy intake and energy expenditure. As illustrated in Figure 7.1, weight loss occurs when the body is in negative energy balance, as fat stores must be mobilized in order to meet the body’s energy demands.
Negative energy balance can be induced by a reduction in energy consumed, an increase in energy expended, or a combination of both. In theory, reducing fat stores should be simple; eat less and exercise more. However, as our understanding of obesity has increased so it has become evident that the condition is not simply the result of eating too much and exercising too little. The regulation of body weight is controlled by a complex, and as yet incompletely understood, number of physiological processes which interact with various environmental and societal factors.