Aging affects almost all physiological processes, but changes in body composition and body phenotype are most observable. In this review, we focus on these changes, including loss of bone and muscle and increase in body fat or redistribution of the latter, possibly leading to osteosarcopenic obesity syndrome. We also address low-grade chronic inflammation, prevalent in aging adults and a cause of many disorders including those associated with body composition. Changes in dietary intake and nutritional requirements of older individuals, that all may lead to some disturbances on tissue and organ levels, are discussed as well. Finally, we discuss the hormonal changes in the aging body, considering each of the tissues, bone, muscle and fat as separate endocrine organs, but yet in the continuous interface and communication with each other. Although there are still many unanswered questions in this field, this review will enable the readers to better understand the aging human body and measures needing to be implemented toward reducing impaired health and disability in older individuals.

Osteosarcopenic obesity (OSO) syndrome describes the simultaneous deterioration of bone, muscle and excess fat, resulting in reduced functionality and systemic metabolic dysregulation. The key component contributing to this may be ectopic fat in the viscera, bone and muscle. OSO research to date is summarized, and the revised criteria for its identification for research purposes are reviewed and proposed, including new criteria to assess visceral fat in males and females. Finally, nutritional and physical activity recommendations are consolidated into a treatment algorithm, which can be validated in future studies and which may also be applied to preventative management.

Some of the universal characteristics of pre-agricultural hominin diets are strikingly different from the modern human diet. Hominin dietary choices were limited to wild plant and wild animal foods, while the modern diet includes more than 70 % of energy consumed from refined sugars, refined vegetable oils, and highly processed cereals and dairy products. The modern diet, with higher intake of fat has also resulted in a higher ratio of omega-6 (n-6) to omega-3 (n-3) polyunsaturated fatty acids (PUFA), contributing to low-grade chronic inflammation (LGCI) and thus promoting the development of many chronic diseases, including obesity and osteoporosis. In this review, we describe the changes in modern diet, focusing on the kind and amount of consumed fat; explain the shortcomings of the modern diet with regard to inflammatory processes; and delineate the reciprocity between adiposity and inflammatory processes, with inflammation being a common link between obesity and osteoporosis. We present the evidence that overconsumption of n-6 PUFA coupled with under-consumption of n-3 PUFA results in LGCI and, along with the increased presence of reactive oxygen species, leads to a shift in mesenchymal stem cells (precursors for both osteoblasts and adipocytes) lineage commitment toward increased adipogenesis and suppressed osteoblastogenesis. In turn, high n-6 to n-3 PUFA ratios in the modern diet, coupled with increased synthesis of pro-inflammatory cytokines due to adiposity, propagate obesity and osteoporosis by increasing or maintaining LGCI.

Objective To investigate protein intakes across demographic characteristics in relation to dietary patterns and functional outcomes in older adults. Design Observational and cross-sectional study. Setting Non-institutionalized participants from the 2005–2014 National Health and Nutrition Examination Survey. Participants Data from 11,680 adults were categorized into 51–60 years (n= 4,016), 61–70 years (n=3,854), and 71 years and older (n=3,810) for analysis. Measurements Adults were stratified by meeting or not meeting the protein recommendation (0.8 g/kg/d) to compare demographics, diet quality with Healthy Eating Index– 2015, functional limitations, and other dietary intakes. Dietary recalls were collected using the multiple pass method. Data analyses were weighted to create a nationally–representative sample. Results Dietary protein intakes were significantly lower in older age groups, with up to 46% of the oldest adults not meeting the protein intake recommendation. Participants consuming protein below the recommended intake level had significantly poorer diet quality across all age groups (P<0.01), however, overall diet quality was better in older adults. Those not meeting the protein recommendation were more likely to have intakes of other nutrients below recommended levels. Those below the protein recommendation had significantly more functional limitations across all age groups, while grip strength was significantly lower in those over 70 years old. Conclusion Lower protein intakes, and lower diet quality and physical functioning are related in an aging population. Meeting the protein recommendation was linked to better overall diet quality and may be protective of lean mass; therefore, evaluation of individual characteristics which may affect protein intakes is crucial in supporting older adults to meet their protein needs.

Conditions related to body composition and aging, such as osteopenic obesity, sarcopenia/sarcopenic obesity, and the newly termed osteosarcopenic obesity (triad of bone muscle and adipose tissue impairment), are beginning to gain recognition. However there is still alack of definitive diagnostic criteriafor these conditions. Little is known about the long-term impact of these combined conditions of osteoporosis, sarcopenia, and obesity in older adults. Many may go undiagnosed and progress untreated. Therefore, the objective of this research is to creatediagnostic criteriafor osteosarcopenic obesity in older women. The proposeddiagnostic criteriaare based ontwo types of assessments: physical,via body composition measurements, andfunctional,via physical performance measures. Body composition measurements such asT-scores for bone mineral density, appendicular lean mass for sarcopenia, and percent body fat could all be obtained via dual energy X-ray absorptiometry. Physical performance tests: handgrip strength, one-leg stance, walking speed, and sit-to-stand could be assessed with minimal equipment. A score could then be obtained to measure functional decline in the older adult. Fordiagnosing osteosarcopenic obesityand other conditions related to bone loss and muscle loss combined with obesity, a combination of measures may more adequately improve the assessment process.