4.3. Subjective Variables
eating behaviors, mood disturbance, fullness, ’ appetite
No group × time effects were observed for changes in food and eating behaviors, sleep quality, or mood disturbance as assessed via our series of validated questionnaires. Across the entire sample, mood disturbance was reduced (−1.5; Notably, use of the thermogenic supplement did not appear to result in decreased sleep quality over the month-long intervention as assessed via the PSQI. These results indicated that daily intake of a supplement containing 300 mg caffeine, including 150 mg taken in the afternoon hours, did not adversely affect sleep to a meaningful degree. This is a meaningful finding for potential users of thermogenic supplements containing central nervous stimulants such as caffeine, as these users would likely prefer to avoid disruptions in sleep quality and related downstream consequences on athletic performance in addition to quality of life. Changes in subjective hunger, emotional eating, and uncontrolled eating as assessed via the TFEQ-R18 were also not statistically different between groups. Therefore, use of the protein and/or thermogenic supplement did not appear to affect experiences of appetite or overeating in the current investigation, regardless of the potentially anorexigenic effects of these compounds. Contrary to our findings that four weeks of a caffeinated supplement (approximately 300 mg/day) did not adversely affect sleep quality in young, trained, individuals, Sowinski et al. [Sowinski and colleagues also elicited data pertaining to subjects’ appetite, hunger, satisfaction from food, fullness, energy, and overall diet quality, assessing each item on a ten-point visual analog scale. In line with our results, the authors found no differences between those given a thermogenic supplement or placebo for any outcome. However, beyond the findings of Sowinski et al., there currently exists a dearth of research related to the chronic effects of similar supplementation interventions on subjective variables in populations similar to ours. 