Malnutrition due to starvation, disease or ageing can be defined as “a state resulting from lack of uptake or intake of nutrition leading to altered body composition (decreased fat free mass) and body cell mass leading to diminished physical and mental function and impaired clinical outcome from disease” [1]. Although this definition is well-accepted, the condition lacks clear and generally accepted diagnostic criteria.
During the famine catastrophes in Africa during the 1960s, WHO brought attention to the medical aspects of starvation [2]. The concepts of kwashiorkor and marasmus were introduced to define a particular protein deficient condition characterized by hypo-albuminemic peripheral edema and ascites, i.e. kwashiorkor, and a particular energy deficient state characterized by severe weight loss due to mainly fat store depletion, i.e. marasmus. This classification did not turn out as relevant for the recognition and diagnosis of malnutrition that was increasingly observed in hospitals in the Western countries during the later decades of the last century. Since depletion is usually a combined deficiency and loss of protein and energy, the general term of protein-energy malnutrition (PEM) became widely accepted [3]. Clinical characteristics used to define PEM have varied over time, but there was never a consensus on diagnostic criteria. Various combinations of clinical, anthropometrical, biochemical and immunological measures were used (e.g. Refs. [4], [5]).
The last decades have seen the advent of several malnutrition screening tools that have reached increased acceptance due to their clinical feasibility. These screening tools combine about the same variables, i.e. weight loss, body mass index (BMI), signs of eating difficulties (e.g. appetite loss or reduced food intake) and a grading of on-going disease severity. ESPEN recognizes the following risk screening tools to be used in the hospital, elderly care and community settings; Nutritional Risk Screening 2002 (NRS-2002), Mini Nutritional Assessment-Short Form (MNA-SF) and Malnutrition Universal Screening Tool (MUST) [6]. The major use of these tools is to screen for malnutrition risk. The subsequent clinical actions should be assessment of underlying mechanisms and type of nutritional problems, in order to design personalized nutritional therapies. The diagnostic procedure usually ends there. The reasons for this are many-fold. One may be the imperative to focus on the implementation of the malnutrition risk screening procedures over the past years. Another apparent reason is the lack of consensus over diagnostic criteria. In the absence of such criteria, it is difficult to distinguish the effectiveness and efficacy of nutritional therapies when applied in different phases of the patients decline into malnutrition. The effects of nutritional therapy given at an early stage, before body protein and energy stores have been depleted, might differ as compared to when given at a late stage with overt depletion.
Previous important consensus initiatives have been attempted [7], [8], [9], and the outcomes have reflected the complexity of the issue and the difficulties to reaching consensus. It was considered that these results “… may fuel the discussion within the nutritional societies, which will most ideally lead to an international consensus on a definition and operationalism of malnutrition” [7].
There is moreover a confusion of terminology. Malnutrition, protein-energy malnutrition, undernutrition, depletion, wasting, cachexia are some of the terms used to denominate the condition that ensues deficiencies of macro- and micronutrients and catabolism of protein and energy stores due to disease and ageing. The malnutrition-related concepts cachexia [10], [11], sarcopenia [11], [12] and frailty [13] are today well-established. The current initiative doesn't challenge their definitions.
This statement is aimed at helping clinicians to effectively provide therapeutic nutritional interventions, and accordingly, to document clinically relevant malnutrition, and moreover to facilitate documentation in the Disease Related Group (DRG) and International Classification of Diseases (ICD) systems.
Malnutrition should be recognized as a serious clinical risk factor. In real clinical settings this is not the case, partly due to the lack of simple and unequivocal diagnostic criteria. It is crucial to reach consensus on diagnostic criteria for malnutrition in order to unify the terminology (e.g. for ICD-10), to enhance the legitimacy of nutritional practices, to improve clinical care and to move the clinical and scientific nutrition field forward. For this purpose the European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a consensus group with a clear mission to provide criteria for the diagnosis of malnutrition.
The primary objective was to reach consensus for simple, clear and generally applicable diagnostic criteria of malnutrition in the sense of energy and protein store depletion. The intention was to provide criteria that are independent from etiologic mechanisms, and that can be used for all patients and in all clinical settings.
Secondary objectives were to try to bring clarity to the nutritional terminology, and to provide a general nutritional disorders concept tree.