Implicit satiety goals and food-related expectations predict portion size in older adults: Findings from the BAMMBE cohort.

Portion size selection is an indicator of appetite and within younger adults, is predicted by factors such as expected satiety, liking and motivations to achieve an ideal sensation of fullness (i.e., implicit satiety goals). Currently, there is limited research available on the determinants of portion size selection within older adults. Therefore, the current study aimed to examine the relationship between individual differences in implicit satiety goals, food-related expectations, and portion size selection in older adults. Free-living older adult Singaporeans (N = 115; Nmales = 62; age: M = 66.21 years, SD = 4.78, range = 60-83 years) participated as part of the Brain, Ageing, Microbiome, Muscle, Bone, and Exercise Study (BAMMBE). Participants completed questionnaires on their subjective requirements for experiencing different states of satiety and food-related expectations (i.e., liking, how filling) as well as a computerised portion size selection task. Using a multiple regression, we found that goals to feel comfortably full (B = 3.08, SE = 1.04, t = 2.96, p = .004) and to stop hunger (B = -2.25, SE = 0.82, t = -2.75, p = .007) significantly predicted larger portion size selection (R2 = 0.24, F(4,87) = 6.74, p < .001). Larger portion sizes (R2 = 0.53, F(5,90) = 20.58, p < .001) were also predicted by greater expected satiety (B = 0.47, SE = 0.09, t = 5.15, p < .001) and lower perceptions of how filling foods are (B = -2.92, SE = 0.77, t = -3.79, p < .001) but not liking (B = -0.09, SE = 0.91, t = -0.10, p = .925) or frequency (B = -18.42, SE = 16.91, t = -1.09, p = .279) of consumption of target foods. Comparing our findings to results of studies conducted with younger adults suggests the influence of factors such as satiety related goals on portion size selection may change with ageing while the influence of other factors (e.g., expected satiety/fullness delivered by foods) may remain consistent. These findings may inform future strategies to increase/decrease portion size accordingly to ensure older adults maintain an appropriate healthy weight.

Age-Related Differences in Immunological Responses to SARS-CoV-2.

There is a striking age-related disparity in the prevalence and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 infections, which might be explained by age-dependent immunological mechanisms. These include age-related physiological differences in immunological responses, cross-neutralizing antibodies, and differences in levels and binding affinity of angiotensin-converting enzyme 2, the SARS-CoV-2 target receptor; antibody-dependent enhancement in adults manifesting with an overexuberant systemic inflammation in response to infection; and the increased likelihood of comorbidities in adults and the elderly. Emerging immunological phenomena such as Pediatric Multi-System Inflammatory Disorder Temporally associated with SARS-CoV-2 or Multisystem Inflammatory Syndrome in Children are now being observed, though the underlying mechanisms are still unclear. Understanding the mechanisms through which pediatric patients are protected from severe novel coronaviruses infections will provide critical clues to the pathophysiology of coronavirus disease 2019 infection and inform future therapeutic and prophylactic interventions. Asymptomatic carriage in children may have major public health implications, which will have an impact on social and health care policies on screening and isolation practices, school reopening, and safe distancing requirements in the community.