Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- Creators: Johnston, Carol
Description
Gastrointestinal (GI) complaints are prevalent among athletes. Fermented foods with pre-or probiotic features may relieve GI symptoms by improving gut health. This study aimed is to examine the impact of a nutritional supplement containing fermented whey protein with Galacto-oligosaccharide (GOS) fiber on GI distress among well-trained athletes over time by analyzing self-reported GI complaints without a control group. This quasi-experimental clinical trial consisted of a 3-week baseline period, reflected by two baseline measurements on Day 1 and Day 22, which was followed by a 3-week intervention period, reflected by a post-intervention measurement on Day 43, in which athletes added 15g of a fermented whey protein product to their diet. The primary outcome was based on the self-reported gastrointestinal symptom rating scale (GSRS), and the secondary outcome was based on a daily questionnaire, in which daily GI complaints and exercise occurrences were reported. Tertiary outcomes included a 24-hour diet recall (ASA24) and self-reported diet quality (REAP). Outcomes obtained during baseline (Day 1 and Day 22 average) were compared to those post-intervention (Day 43). Statistical significance was set at P<0.05. A total of n=50 athletes (24.7±4.5 years) with GI issues were included in the study. Five individual items of the GSRS including abdominal pain, acid reflux, bloating, burping, and loose stools reflected significantly lower scores on Day 43 in comparison to baseline (P≤0.028). A total of 78% reported GI complaints at baseline, and 61% of the participants reported lower GI complaints on Day 43 after supplementation in comparison to baseline (P=0.004). Further research is needed to explore the potential benefits of a hydrolyzed and fermented whey protein with prebiotics in a more controlled setting among athletic populations.
ContributorsClear, Anna Marie Grace (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Wharton, Christopher (Committee member) / Arizona State University (Publisher)
Created2023
Description
Sleep is an essential biological requirement to sustain human life and a critical component for athletes. There has been a rising trend for poor sleep in the general population and the problem persists as well within the athletic population. Research has demonstrated numerous benefits of optimized sleep on athletic performance and athlete wellness. Further investigation of potential dietary strategies to improve self-perceived sleep quality is warranted. This study examined the differences in perceived sleep quality and wellness between a 3-week baseline period and after a 3-week supplementation period, in which participants consumed a dietary supplement containing fermented whey protein + galacto-oligosaccharides (GOS) + casein protein daily. Validated questionnaires, namely, Athens Insomnia Scale (AIS), Physical Health Questionnaire (PHX), Kessler-6 Mental Stress Scale (K6) were used to measure perceived sleep quality and wellness on Day 1, Day 22 and Day 43. Additionally, multiple 24-h dietary recalls (ASA24), and food quality using the validated Rapid Eating Assessments for Participants (REAP) questionnaire, were used to assess dietary patterns throughout the study, while exercise occurrence was tracked through a self-developed daily questionnaire. A total of 54 healthy active adults (age=18-35yrs) experiencing gastro-intestinal (GI) complaints were included in the trial, and 50 participants were included in the final analysis. Significantly lower AIS-8 total scores were found on Day 43 compared to Day 22 while controlled for Day 1 (Day 43: 4.36 ± 3.68 versus Day 22: 5.02 ± 4.11, F=4.379 (1, 50), p=0.042), while no differences were found for wellbeing (p≥ 0.180). Dietary intake, food quality and exercise frequency did not change over time (p≥0.080). These results suggested that a daily protein + GOS supplement was associated with a decrease in AIS-8 total scores suggesting improved perceived sleep quality among athletes after 3 weeks. A controlled research study should confirm these results in the future. More research is required to assess the effects of protein + prebiotic supplementation on sleep parameters among athletes.
ContributorsChan, Yat (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Wharton, Christopher (Committee member) / Arizona State University (Publisher)
Created2023
Description
Background: Vegan and vegetarian diets have gained in popularity in recent years. Stated reasons for this include some possible health benefits and concerns of animal welfare. Though considered to be nutritionally adequate, questions remain over whether current protein recommendations of 0.8 g/kg/d are sufficient to maintain body processes and growth. Protein is unique in that it is the only macronutrient that contains nitrogen. Its status can be determined through nitrogen balance analysis of the urine if protein content of the diet is known. Nitrogen balance is considered the gold standard for determining protein intake requirements. A negative balance indicates a catabolic state, whereas a positive nitrogen balance is seen during anabolism. In healthy people, nitrogen equilibrium is desired under normal circumstances. This equilibrium reflects the net synthesis and breakdown of proteins. While nitrogen balance techniques have been used for decades, currently, there are no known studies measuring nitrogen balance and protein intake in strict vegans. Methods: Twenty vegan, inactive, male participants were recruited and received a 5-day eucaloric diet with a known protein content held constant at 0.8 g/kg/d. On day five, 24-hour urine was collected by participants and aliquoted for future analysis. Nitrogen content of the urine was determined through photometric assay and compared to the known nitrogen content of the diet to calculate nitrogen balance status.
Results: Mean absolute nitrogen balance (-1.38 ± 1.22 g/d, effect size = -1.13) was significantly lower than zero (equilibrium) (p < .001). Mean relative nitrogen balance (-18.60 ± 16.96 mg/kg/d, effect size = -1.10) was significantly lower than zero (p < .001). There were no correlations seen between nitrogen balance and age, years as vegan, or fat- free mass.
Conclusion: Consuming 0.8 g/kg/d of protein is insufficient to produce nitrogen balance in long-term vegans.
ContributorsBartholomae, Eric (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Wharton, Christopher (Committee member) / Lee, Chong (Committee member) / Kressler, Jochen (Committee member) / Arizona State University (Publisher)
Created2022