Sarcopenic obesity is defined as the presence of high fat mass and low muscle mass combined with low physical function, and it is closely related with the onset of cardiovasular diseases (CVD). The existing anthropometric indices, which are being utilised in clinical practice as predictors of CVD, may also be used to screen sarcopenic obesity, but their feasibility remained unknown. Using cross-sectional data of 2031 participants aged 70–84 years (mean age, 75·9 ± 3·9 years; 49·2 % women) from the Korean Frailty and Aging Cohort Study, we analysed the association of anthropometric indices, including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and weight-adjusted waist index (WWI) with sarcopenic obesity. Body composition was measured using dual-energy X-ray absorptiometry. Higher WWI, WHtR and WC quartiles were associated with higher risk of sarcopenic obesity; the odds ratio (OR) of sarcopenic obesity were highest in the fourth quartile of the WWI (OR: 10·99, 95 % CI: 4·92–24·85, P for trend < 0·001). WWI provided the best diagnostic power for sarcopenic obesity in men (area under the receiver operating characteristic curve: 0·781, 95 % CI: 0·751–0·837). No anthropometric indices were significantly associated with sarcopenic obesity in women. WWI was the only index that was negatively correlated with physical function in both men and women. WWI showed the strongest association with sarcopenic obesity, defined by high fat mass and low muscle mass combined with low physical function only in older men. No anthropometric indices were associated with sarcopenic obesity in older women.

Obesity is associated with increased muscle mass and muscle strength. Methods taking into account the total body mass to reveal obese older individuals at increased risk of functional impairment are needed. Therefore, we aimed to detect methods to identify obese older adults at increased risk of functional impairment. Home-dwelling older adults (n 417, ≥ 70 years of age) were included in this cross-sectional study. Sex-specific cut-off points for two obesity phenotypes (waist circumference (WC) and body fat mass (FM %)) were used to divide women and men into obese and non-obese groups, and within-sex comparisons were performed. Obese women and men, classified by both phenotypes, had similar absolute handgrip strength (HGS) but lower relative HGS (HGS/total body mass) (P < 0·001) than non-obese women and men, respectively. Women with increased WC and FM %, and men with increased WC had higher appendicular skeletal muscle mass (P < 0·001), lower muscle quality (HGS/upper appendicular muscle mass) (P < 0·001), and spent longer time on the stair climb test and the repeated sit-to-stand test (P < 0·05) than non-obese women and men, respectively. Absolute muscle strength was not able to discriminate between obese and non-obese older adults. However, relative muscle strength in particular, but also muscle quality and physical performance tests, where the total body mass was taken into account or served as an extra load, identified obese older adults at increased risk of functional impairment. Prospective studies are needed to determine clinically relevant cut-off points for relative HGS in particular.

It is unknown if time-restricted feeding confers a protective effect on the physical function of older adults. The aim of this study was to assess prolonged nightly fasting in association with performance-based lower-extremity function (LEF) in a large population of community-dwelling older adults. A cross-sectional study was carried out among 1226 individuals ≥64 years from the Seniors-ENRICA-II (Study on Nutrition and Cardiovascular Risk in Spain) cohort. Habitual diet was assessed through a validated diet history. Fasting time was classified into the following categories: ≤9, 10–11 and ≥12 h/d (prolonged nightly fasting). Performance-based LEF was assessed with the Short Physical Performance Battery (SPPB). After adjusting for potential confounders, a longer fasting period was associated with a higher likelihood of impaired LEF (OR for the second and third categories v. ≤ 9 h/d fasting: 2·27 (95 % CI 1·56, 3·33) and 2·70 (95 % CI 1·80, 4·04), respectively; P trend < 0·001). Fasting time showed a significant association with the SPPB subtests balance impairment (OR for highest v. shortest fasting time: 2.48; 95 % CI 1·51, 4·08; P trend = 0·001) and difficulty to rise from a chair (OR 1·47; 95 % CI 1·05, 2·06; P trend = 0·01). The risk associated with ≥12 h fasting among those with the lowest levels of physical activity was three times higher than among those with ≤9 h fasting with the same low level of physical activity. Prolonged nightly fasting was associated with a higher likelihood of impaired LEF, balance impairment, and difficulty to rise from a chair in older adults, especially among those with low levels of physical activity.

The aim of the study was to investigate whether the interaction of physical activity (PA) and protein intake is associated with physical function (PF). The women from the Osteoporosis Risk Factor and Fracture Prevention Study (n 610) completed a questionnaire on lifestyle factors and PA and underwent PF and body composition measurements at baseline (BL) and over 3 years of follow-up (3y-FU). PA was categorised according to WHO cut-off PA = 0, 0 < PA < 2·5 and PA ≥ 2·5 h/week. Protein intake was calculated from the 3-d food record at baseline and categorised according to the Nordic Nutrition Recommendations <1·1 and ≥1·1 g/kg body weight (BW). The results showed in univariate ANOVA at the baseline and at the 3-year follow-up, women with high PA ≥ 2·5 h/week and protein intake ≥ 1·1 g/kg BW had higher grip strength adjusted for BMI, higher mean number of chair rises, faster mean walking speed, higher modified mean short physical performance battery score and lower mean fat mass compared with other interaction groups. High PA and protein intake were associated with lower BMI despite significantly higher energy intake. In conclusion, higher PA and protein intake interaction was associated with greater PF and lower fat mass, but the association with relative skeletal muscle index and muscle mass was inconclusive. The present study gives noteworthy information for preventing sarcopenia.

During and after hospitalisation, older adults are recommended to consume 1·2–1·5 g of protein/kg body weight per d (g/kg per d) to improve recovery. This randomised controlled trial studied the effectiveness of a 12-week intervention with protein-enriched foods and drinks by following-up seventy-five older patients (mean age: 76·8 (sd 6·9) years) during their first 6 months after hospital discharge. Primary outcomes were protein intake and physical performance (measured with Short Physical Performance Battery (SPPB)). Secondary outcomes for physical recovery were gait speed, chair-rise time, leg-extension strength, hand-grip strength, body weight, nutritional status (Mini Nutritional Assessment), independence in activities of daily living (ADL) and physical activity. The intervention group consumed more protein during the 12-week intervention period compared with the control group (P<0·01): 112 (sd 34) g/d (1·5 (sd 0·6) g/kg per d) v. 78 (sd 18) g/d (1·0 (sd 0·4) g/kg per d). SPPB total score, gait speed, chair-rise time, body weight and nutritional status improved at week 12 compared with baseline (time effect P<0·05), but were not different between groups. Leg-extension strength, hand-grip strength and independence in ADL did not change. In conclusion, protein-enriched products enabled older adults to increase their protein intake to levels that are higher than their required intake. In these older adults with already adequate protein intakes and limited physical activity, protein enrichment did not enhance physical recovery in the first 6 months after hospital discharge.

Dietary protein intake might be beneficial to physical function (PF) in the elderly. We examined the cross-sectional and prospective associations of protein intake of g/kg body weight (BW), fat mass (FM) and lean mass (LM) with PF in 554 women aged 65·3–71·6 years belonging to the Osteoporosis Risk Factor and Prevention Fracture Prevention Study. Participants filled a questionnaire on lifestyle factors and 3-d food record in 2002. Body composition was measured by dual-energy X-ray absorptiometry, and PF measures were performed at baseline and at 3-year follow-up. Sarcopaenia was defined using European Working Group on Sarcopenia in Older People criteria. At the baseline, women with higher protein intake (≥1·2 g/kg BW) had better performance in hand-grip strength/body mass (GS/BM) (P=0·001), knee extension/BM (P=0·003), one-leg stance (P=0·047), chair rise (P=0·043), squat (P=0·019), squat to the ground (P=0·001), faster walking speed for 10 m (P=0·005) and higher short physical performance battery score (P=0·004) compared with those with moderate and lower intakes (0·81–1·19 and ≤0·8 g/kg BW, respectively). In follow-up results, higher protein intake was associated with less decline in GS/BM, one-leg stance and tandem walk for 6 m over 3 years. Overall, results were no longer significant after controlling for FM. Associations were detected between protein intake and PF in non-sarcopaenic women but not in sarcopaenic women, except for change of GS (P=0·037). Further, FM but not LM was negatively associated with PF measures (P<0·050). This study suggests that higher protein intake and lower FM might be positively associated with PF in elderly women.