The impact of computed tomography-defined sarcopenia on outcomes in head and neck cancer has been well described. Sarcopenic obesity (SO) (depleted muscle mass combined with obesity) may pose a more serious risk than either condition alone. We investigated SO and its impact on survival and critical weight loss (≥ 5 %) in patients with head and neck cancer who received curative radiotherapy (± other modalities). Retrospective analysis of computed tomography cross-sectional muscle at cervical (C3), thoracic (T2) and lumbar (L3) regions was conducted. Patients were grouped by BMI and sarcopenia status based on established thresholds. A total of 413 patients were included for analysis, the majority having oropharyngeal carcinoma (52 %), and 56 % received primary concurrent chemoradiotherapy. The majority of the cohort (65 %) was overweight or obese (BMI ≥ 25 kg/m2). Sarcopenia was found in 43 %, with 65 % having SO (n 116), equating to 28 % of the whole cohort. Critical weight loss was experienced by 58 % (n 238). A significantly higher proportion of patients with SO experienced critical weight loss (n 70 v. 19, P < 0·001) and were four times more likely to do so during treatment (OR 4·1; 95 % CI 1·5, 7·1; P = 0·002). SO was not found to impact on overall or cancer-specific survival; however, in patients with sarcopenia, those with SO had better overall survival (median 9·1 v. 7·0 years; 95 % CI 5·2, 16·8; P = 0·021). SO at the time of presentation in patients with head and neck cancer is predictive of critical weight loss during treatment, and muscle evaluation can be useful in identifying patients at nutritional risk regardless of BMI and obvious signs of wasting.

(Protein–energy) malnutrition in individuals living with obesity presents complex diagnostic challenges due to the distinctive physiological characteristics of obesity. This narrative review critically examines the identification of malnutrition within the population with obesity, distinguishing malnutrition in obesity from related conditions such as sarcopenic obesity. While noting some shared features, the review highlights key differences between these conditions. The review also highlights the limitations of current malnutrition screening tools, which are not designed for individuals living with obesity. These tools primarily rely on anthropometric measurements, neglecting (among others) nutrient intake assessment, which hinders accurate malnutrition detection. Additionally, this review discusses limitations in existing diagnostic criteria, including the Global Leadership Initiative on Malnutrition (GLIM) criteria, when applied to individuals living with obesity. Challenges include the identification of appropriate cut-off values for phenotypic criteria (unintentional weight loss, low body mass index and muscle mass) and aetiological criteria such as reduced food intake and inflammation for the population with obesity. Overall, this review emphasises the need for modified screening tools and diagnostic criteria to recognise and assess malnutrition in obesity, leading to improved clinical outcomes and overall wellbeing.

Malnutrition is a key factor in metabolic syndrome (MS) and sarcopenia, assessing the nutritional status of these patients is a pressing issue. The purpose of this study was to clarify sarcopenia and sarcopenic obesity in patients with MS based on nutritional status. This was a case–control study between MS/non-MS. Body composition was measured by dual-energy X-ray absorptiometry. Muscle function was assessed by handgrip strength, five times sit-to-stand test, gait speed test and short physical performance battery (SPPB). The Mini Nutritional Assessment (MNA) was performed to assess the nutritional status in the participants in this study. Overall, a total of 56 % and 13 % of participants suffered from possible sarcopenia and sarcopenia, respectively. There was a higher rate of possible sarcopenic obesity in the MS group than in the non-MS group (48·9 % v. 24·7 %, P < 0·01), and all the sarcopenia participants in the MS group had sarcopenic obesity. MNA score was significantly associated with sarcopenia status (P < 0·01). The MNA combined with body fat score showed better acceptable discrimination for detecting sarcopenic obesity and sarcopenia in MS (AUC = 0·70, 95 % CI 0·53, 0·86). In summary, there was a higher prevalence of possible sarcopenic obesity in MS, and all the MS patients with sarcopenia had sarcopenic obesity in the present study. We suggest that the MNA should be combined with body fat percentage to assess the nutritional status of MS participants, and it also serves as a good indicator for sarcopenia and sarcopenic obesity in MS.

Sarcopenic obesity is regarded as a risk factor for the progression and development of non-alcoholic fatty liver disease (NAFLD). Since male sex is a risk factor for NAFLD and skeletal muscle mass markedly varies between the sexes, we examined whether sex influences the association between appendicular skeletal muscle mass to visceral fat area ratio (SVR), that is, an index of skeletal muscle mass combined with abdominal obesity, and the histological severity of NAFLD. The SVR was measured by bioelectrical impedance in a cohort of 613 (M/F = 443/170) Chinese middle-aged individuals with biopsy-proven NAFLD. Multivariable logistic regression and subgroup analyses were used to test the association between SVR and the severity of NAFLD (i.e. non-alcoholic steatohepatitis (NASH) or NASH with the presence of any stage of liver fibrosis). NASH was identified by a NAFLD activity score ≥5, with a minimum score of 1 for each of its categories. The presence of fibrosis was classified as having a histological stage ≥1. The SVR was inversely associated with NASH in men (adjusted OR 0·62; 95 % CI 0·42, 0·92, P = 0·017 for NASH, adjusted OR 0·65; 95 % CI 0·43, 0·99, P = 0·043 for NASH with the presence of fibrosis), but not in women (1·47 (95 % CI 0·76, 2·83), P = 0·25 for NASH, and 1·45 (95 % CI 0·74, 2·83), P = 0·28 for NASH with the presence of fibrosis). There was a significant interaction for sex and SVR (Pinteraction = 0·017 for NASH and Pinteraction = 0·033 for NASH with the presence of fibrosis). Our findings show that lower skeletal muscle mass combined with abdominal obesity is strongly associated with the presence of NASH only in men.

The most important issue for the clinical application of sarcopenic obesity (SO) is the lack of a consensus definition. The aim of the present study was to determine the best measurement for SO by estimating the association between various definitions and the risk of falls and metabolic syndrome (MS). We studied a community of 765 adults aged 65 years and older in 2015–2017. Sarcopenia obesity was measured by sarcopenia (defined by low muscle mass with either low handgrip strength or low gait speed or both) plus obesity (defined by waist circumference, body fat percentage and BMI). The MS was defined according to the National Cholesterol Education Program ATP III. Logistic regression models were constructed to examine the relationships between sarcopenia obesity and risk of fall and MS. In the analysis of the fall risk with SO defined by waist circumference, the participants with non-sarcopenia/non-obesity were treated as the reference group. The OR to fall in participants with SO was 10·16 (95 % CI 2·71, 38·13) after adjusting for confounding covariates. In the analysis of the risk of the MS between participants with individual components of sarcopenia coupled with obesity defined by waist circumference, the risk was statistically significant for low gait speed (OR: 7·19; 95 % CI 3·61, 14·30) and low grip strength (OR: 9·19; 95 % CI 5·00, 16·91). A combination of low grip strength and abdominal obesity for identifying SO may be a more precise and practical method for predicting target populations with unfavourable health risks, such as falls risk and MS.

Our understanding of body composition (BC) variability in contemporary populations has significantly increased with the use of imaging techniques. Abnormal BC such as sarcopenia (low muscle mass) and obesity (excess adipose tissue) are predictors of poorer prognosis in a variety of conditions or clinical situations. As a catabolic illness, a defining feature of cancer is muscle loss. Although the conceptual model of wasting in cancer is typically conceived as involuntary weight loss leading to low body weight, recent studies have shown that both sarcopenia and cachexia can be present with obesity. The combination of low muscle and high adipose tissue (sarcopenic obesity) is an emerging abnormal BC phenotype prevalent across the body weight, and hence BMI spectra. Sarcopenia and sarcopenic obesity in cancer are in most instances occult conditions, which have been independently associated with higher incidence of chemotherapy toxicity, shorter time to tumour progression, poorer outcomes of surgery, physical impairment and shorter survival. Although the mechanisms are yet to be fully understood, the associations with poorer clinical outcomes emphasise the value of nutritional assessment as well as the need to develop appropriate interventions to countermeasure abnormal BC. Sarcopenia and sarcopenic obesity create diverse nutritional requirements, highlighting the compelling need for a more comprehensive and differentiated understanding of energy and protein requirements in this heterogeneous population.

The first reports of accurate skeletal muscle mass measurement in human subjects appeared at about the same time as introduction of the sarcopenia concept in the late 1980s. Since then these methods, computed tomography and MRI, have been used to gain insights into older (i.e. anthropometry and urinary markers) and more recently developed and refined methods (ultrasound, bioimpedance analysis and dual-energy X-ray absorptiometry) of quantifying regional and total body skeletal muscle mass. The objective of this review is to describe the evolution of these methods and their continued development in the context of sarcopenia evaluation and treatment. Advances in these technologies are described with a focus on additional quantifiable measures that relate to muscle composition and ‘quality’. The integration of these collective evaluations with strength and physical performance indices is highlighted with linkages to evaluation of sarcopenia and the spectrum of related disorders such as sarcopenic obesity, cachexia and frailty. Our findings show that currently available methods and those in development are capable of non-invasively extending measures from solely ‘mass’ to quality evaluations that promise to close the gaps now recognised between skeletal muscle mass and muscle function, morbidity and mortality. As the largest tissue compartment in most adults, skeletal muscle mass and aspects of muscle composition can now be evaluated by a wide array of technologies that provide important new research and clinical opportunities aligned with the growing interest in the spectrum of conditions associated with sarcopenia.