OBJECTIVE: This umbrella review aimed to assess whether dietary protein intake with regard to quantitative (higher vs. lower dietary protein intake) and qualitative considerations (total, plant-based or animal-based protein intake) affects body weight (BW), fat mass (FM) and waist circumference (WC).
METHODS: A systematic literature search was conducted in PubMed, Embase and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with and without meta-analyses of prospective studies published between 04 October 2007 and 04 January 2022. Methodological quality and outcome-specific certainty of evidence of the retrieved SRs were assessed by using AMSTAR 2 and NutriGrade, respectively, in order to rate the overall certainty of evidence using predefined criteria.
RESULTS: Thirty-three SRs were included in this umbrella review; 29 were based on randomised controlled trials, a few included cohort studies. In studies without energy restriction, a high-protein diet did not modulate BW, FM and WC in adults in general (all \"possible\" evidence); for older adults, overall certainty of evidence was \"insufficient\" for all parameters. Under hypoenergetic diets, a high-protein diet mostly decreased BW and FM, but evidence was \"insufficient\" due to low methodological quality. Evidence regarding an influence of the protein type on BW, FM and WC was \"insufficient\".
CONCLUSIONS: \"Possible\" evidence exists that the amount of protein does not affect BW, FM and WC in adults under isoenergetic conditions. Its impact on the reduction in BW and FM under hypoenergetic conditions remains unclear; evidence for an influence of protein type on BW, FM and WC is \"insufficient\".

OBJECTIVE: The recent consensus statement of ESPEN and EASO recommends reviewing existing datasets to assess the prevalence of sarcopenic obesity based on the new definition and diagnostic criteria. Therefore, this study aimed to determine the prevalence of sarcopenic obesity in a population-based study and to assess the association of this new definition with clinical traits.
METHODS: The KORA (Cooperative Health Research in the Region of Augsburg)-Age baseline examination (2008/2009) comprised 1079 participants aged 65 years and older from southern Germany. Sarcopenic obesity was defined in 998 participants (mean age 75.6 years, 498 women) with complete data according to the 2022 ESPEN and EASO algorithm, which includes reduced handgrip strength, reduced skeletal muscle mass per weight, and elevated fat mass. Body composition was measured using bioelectrical impedance analysis. Associations between sarcopenic obesity and physical activity, disability, multimorbidity, and polypharmacy were assessed using logistic regression analysis.
RESULTS: The overall prevalence of sarcopenic obesity was 4.5 % (5.0 % in men, 4.0 % in women). Sarcopenic obesity was associated with disability (2.87 [CI 1.84-4.48]), multimorbidity (≥ 2 comorbidities; 2.59 [CI 1.23-5.46]), polypharmacy (≥ 5 drugs; 1.96 [CI 1.05-3.63]), cognitive impairment (3.03 [CI 1.51-6.06]) and arthritis (2.66 [CI 1.39-5.07]) after adjusting for age, sex and marital status.
CONCLUSIONS: Sarcopenic obesity is prevalent in the older German population and is associated with several clinical traits. Future longitudinal studies are needed to further elucidate whether the observed associations could be causal.