Dietary Regulation of Successful Aging

The current growth of the older population is unprecedented in U.S. history. Chronic disease and functional limitation commonly develop prior to old age, leading to prolonged physical disability and decreased well-being. The development of chronic disease and loss of independence is associated with lean body mass (LBM) loss and fat mass gain beginning in middle age. Therefore, it is important to identify modifiable factors to mitigate deleterious shifts in body composition to promote successful aging (SA). The concept of SA is associated with longevity, the absence of disease and disability, and subjective components of well-being, however, an operational definition has yet to be established. For this thesis, we defined SA as low cardiometabolic risk, preservation of physical function, and a positive state of well-being. Nutrition is a key driver of SA and is a proposed modulator of cardiometabolic risk, physical function, and well-being in adults. Among nutrients, several studies have identified dietary protein and the omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA; 22:6 n-3), as key supportive nutrients for SA in older adults. Therefore, the overall objective of this dissertation was to determine the effect of nutrition, specifically dietary protein and n-3 PUFAs on SA outcomes of cardiometabolic risk, physical function, and well-being. The central hypothesis of this dissertation was that increased intake of high-quality dietary protein or n-3 PUFAs would improve SA outcomes of cardiometabolic risk, physical function, and well-being in adults. Therefore, one meta-analysis (study 1) and two clinical trials (studies 2 and 3) were designed to test our hypothesis. The objective of the first study was to systematically evaluate the available evidence of randomized control trials assessing the effect of beef and beef’s nutrients on well-being in healthy, adults ≥ 50 years of age to increase physical function and well-being to promote SA. The objective of the second study was to determine and compare the acute effects of a high-protein breakfast containing either animal protein or plant protein on appetite, food intake, energy expenditure, and substrate oxidation in young versus older men to decrease cardiometabolic risk and promote SA. The objective of the third study was to determine the individual and combined effect of protein and n-3 PUFAs on body composition, cardiometabolic risk, indexes of sleep, and mood states in postmenopausal women to decrease cardiometabolic risk and increase physical function, and well-being to promote SA. Collectively, the results suggest high-quality protein and n-3 PUFAs act as potential regulators of SA outcomes. However, additional research is necessary to determine the effectiveness of protein and n-3 PUFA-based nutrition strategies to promote SA

Effects of Time-Restricted Feeding and Whey Protein Isolate Supplementation on Dietary Intake, Mood, and Sleep in a 12-Week Randomized Controlled Trial

Obesity affects adults in the United States, leading to chronic diseases and reduced well-being. Time-Restricted Feeding (TRF) is a type of dietary intervention lacking current data regarding the effectiveness on facets of well-being. This study’s objective was to determine the effect of time-restricted feeding supplemented with whey protein isolate on food intake, sleep, and mood in overweight or obese adults. Nineteen participants were randomly assigned to the control or experimental group: 1) control, TRF, and 2) experimental, TRF with whey protein supplementation. Participants followed the assigned dietary intervention for 12 weeks. Every 4 weeks (baseline, week 4, week 8, and week 12), anthropometrics, including height and weight, were measured along with the Pittsburg Sleep Quality Index (PSQI) questionnaire, Profile of Mood States (POMS) questionnaire, and dietary record results. Additionally, ActiGraphy measured objective sleep quality at week 1 and week 12. There were no differences between the control and protein groups regarding sleep and mood parameters. The PSQI results indicated no difference in sleep between groups. The POMS subscores for tension-anxiety, when controlled for baseline, were different, with a decrease in the protein group compared to the control at week 12 (P \u3c 0.01). Total food consumption was similar between groups. The results suggested whey protein isolate supplementation with TRF may improve outcomes of mood with no effect on sleep. Therefore, a need for further research to investigate the benefits of TRF and protein supplementation on sleep and mood is necessary

Effects of Time-Restricted Feeding and Whey Protein Isolate Supplementation on Dietary Intake, Mood, and Sleep in a 12-Week Randomized Controlled Trial

Obesity affects adults in the United States, leading to chronic diseases and reduced well-being. Time-Restricted Feeding (TRF) is a type of dietary intervention lacking current data regarding the effectiveness on facets of well-being. This study’s objective was to determine the effect of time-restricted feeding supplemented with whey protein isolate on food intake, sleep, and mood in overweight or obese adults. Nineteen participants were randomly assigned to the control or experimental group: 1) control, TRF, and 2) experimental, TRF with whey protein supplementation. Participants followed the assigned dietary intervention for 12 weeks. Every 4 weeks (baseline, week 4, week 8, and week 12), anthropometrics, including height and weight, were measured along with the Pittsburg Sleep Quality Index (PSQI) questionnaire, Profile of Mood States (POMS) questionnaire, and dietary record results. Additionally, ActiGraphy measured objective sleep quality at week 1 and week 12. There were no differences between the control and protein groups regarding sleep and mood parameters. The PSQI results indicated no difference in sleep between groups. The POMS subscores for tension-anxiety, when controlled for baseline, were different, with a decrease in the protein group compared to the control at week 12 (P \u3c 0.01). Total food consumption was similar between groups. The results suggested whey protein isolate supplementation with TRF may improve outcomes of mood with no effect on sleep. Therefore, a need for further research to investigate the benefits of TRF and protein supplementation on sleep and mood is necessary

Primary Care Physicians’ Support of Shared Decision Making for Different Cancer Screening Decisions

BACKGROUND: Despite widespread advocacy, shared decision making (SDM) is not routinely used for cancer screening. To better understand implementation barriers, we describe primary care physicians’ (PCPs’) support for SDM across diverse cancer screening contexts. METHODS: Mailed survey administered to random sample of US-based PCPs. Using multivariable logistic regression we tested association of PCPs’ SDM support with US Preventive Service Task Force (USPSTF) assigned recommendation grade, whether decision pertained to not screening elders, and PCP’s autonomous vs. controlled motivation-orientation for using SDM. RESULTS: PCPs (N=278) were on average aged 52 years, 38% female, and 69% white. 79% endorsed discussing screening benefits as very important to SDM, compared to 64% for discussing risks and 31% for agreeing with patient’s opinion. PCPs were most likely to rate SDM as very important for colorectal cancer (CRC) screening in adults aged 50–75 years (69%), and least likely for CRC screening in adults aged >85 years (34%). Regression results indicated importance of PCPs’ having autonomous or self-determined reasons for engaging in SDM (e.g., believing in benefits of SDM) (OR=2.29, 95% CI 1.87, 2.79). PCPs’ support for SDM varied by USPSTF recommendation grade (overall contrast, chi-square=14.7, p=0.0054), with support greatest for A-grade recommendations. Support for SDM was lower in contexts where decision pertained to not screening elders (OR=0.45, 95% CI 0.35, 0.56). LIMITATIONS: Unknown whether PCP’s perception of importance of SDM behaviors differed by specific screening decision and potential limited ability to generalize findings. CONCLUSIONS: Results highlight need to document SDM benefits and consider specific contextual challenges, such as the level of uncertainty or whether evidence supports recommending/not recommending screening, when implementing SDM across an array of cancer screening contexts