The Food Rating Log included a 9-Point Hedonic Scale for each food item consumed, on which participants rated each food from 1 = “dislike extremely” to 9 = “like extremely.” This Hedonic Scale was originally developed by the U.S. Armed Forces to measure soldiers’ food preferences , but is now used by NASA to assess astronauts’ food preferences, as well. For each participant, I averaged their daily food ratings so that each participant had 8 average daily food rating scores, with 1 being the lowest possible rating and 9 being the highest possible rating. I also conducted exploratory analyses in which I evaluated each food item’s average rating. These exploratory analyses provided insight into which individual food items should be replaced, but these analyses were not included in the study’s main analyses. Every evening , participants completed the Food Monotony Scale , adapted from questions previously used by Redden in NASA-funded studies. The scale included three questions, with two questions asking participants to rate their satisfaction with food variety from 1 to 9 . The remaining question asked participants to rate their boredom with food from 1 to 9 . However, this question was sometimes negatively correlated with the other two questions, suggesting that participants misread the wording of the response options and interpreted 9 as indicating high boredom. Consequently, only the first two items were used in analyses. This resulted in consistent positive correlation between the two items every day. These two items were averaged to calculate 8 average daily satisfaction with variety scores, with 1 indicating lowest satisfaction with variety and 9 indicating highest satisfaction with variety.
If a participant ate half of a food item on Monday and finished that food item on Wednesday,nft vertical farming only their Monday rating was included when calculating that participant’s daily average food rating. On two instances, one participant ate half of a food item in the morning and the other half of that food item in the afternoon. In these instances, I averaged the food ratings and counted them as a single rating. If a participant smelled or tasted but did not eat a food item, the ratings were included in analyses, just as if the food had been eaten. Three participants requested and ate additional food items during days 3 and 4 of the experimental condition. Providing these additional food items was considered acceptable because the trading and sharing of food would likely be common during spaceflight. One participant was provided with another Asian Noodle and Indian Potato Entrée, one participant was provided with two more BBQ Chicken Sandwiches, and one participant was provided with two more applesauce pouches and two more yogurt pouches. Participants’ ratings of these additional food items were included when calculating participants’ daily food ratings. When computing the average rating a particular food item, I averaged ratings if one participant rated the food twice in one day. However, I used only the first rating if a participant rated the same food item on two separate days. This is the same way that I assessed ratings when computing participants’ daily food ratings. However, when computing average ratings of particular food items, I did not include the ratings of any additional items that were requested by participants, so that each participant’s evaluations were weighted the same . Two items were provided twice in the experimental condition. All ratings for the Italian-Style Sandwiches were averaged together to compute its average food rating.
The same approach was used for Turkey Jerky. Eight individuals participated in the study. One participant had a medical emergency on Thursday of the Control week, leading to extreme changes in diet , the inability to weigh the participant in-person, and the delayed completion of surveys. Additionally, it was unknown if the medical event led to altered eating on the other days of the study. Consequently, this participant was excluded from all analyses, leaving a sample size of N = 7.The remaining seven participants were comprised of four females and three males . Participants were not asked to report their precise age, but they all appeared to be in their late 20’s to early 30’s – largely mirroring NASA selected astronaut candidates, whose average age is 34 . The seven participants were of Caucasian descent. A sample that more accuracy reflected the U.S. population would have been preferred, but the sample nevertheless reflected NASA’s former astronaut population . Prior to participating in the study, participants reported they ate the breakfast that was served at work a mean of 2.43 times a week , the lunch a mean of 3.86 times a week , and the dinner a mean of 3.00 times a week . Prior to participating in the study, participants reported most commonly eating their meals at the cafeteria/Mezz at work , at their desks , and at home . No participant reported that they ate foods such as juice or meal replacement bars most days. However, participants did report having food patterns, such as eating protein shakes or oatmeal most days. The anonymous personality survey that participants completed on the last Friday of the study revealed that participants did not have extremely unusual personalities, as compared to norms based on 1,813 respondents . Compared to these norms, participants in this study scored 1.42 points higher on Extroversion, 0.60 points higher on Emotional Stability, and within a half point of every other measured personality trait. These comparisons were computed using the worksheet designed by DeNeui to compare TIPI scores to TIPI norms . These comparisons are shown in Table 5, with each participant depicted as a number.The primary aims of this study were to investigate the impact of a possible commercial space food diet on nutrient intake, food satisfaction, psychological health, and physical health. These aims were investigated by having a sample of aerospace employees eat a diet of commercial, ready-to-eat food for four days one week, and comparing their outcomes to when they ate essentially as normal for four days another week. The seven employees that participated in this study were an ideal sample, given that they had a high workload and represented the type of space enthusiast that will likely seek out commercial space flights, once they become more readily available.
These employees had relatively ordinary eating habits and average personalities, being just slightly more extraverted and emotionally stable than a normedsample. Their adherence to the study was extremely high, largely driven by their desire to contribute to the future of space food.The experimental diet was designed to meet nearly all nutrient recommendations set forth by NASA and to be highly satisfying. Consequently, I had hypothesized that while in the experimental condition, participants would consume the same amount of calories as they did while in the control condition. I had also hypothesized that there would be no significant decline in caloric intake across the four days of each condition. The results of this study coincided with these hypotheses. When caloric intake was computed based on participants’ self-reported food intake, there was no significant difference in caloric intake between conditions and no significant change in caloric intake over time. Although the experimental diet was designed to be highly satisfying, it was nevertheless made entirely of commercial, ready-to-eat food. Consequently, I had hypothesized that while in the experimental condition, participants would rate the food as being slightly less hedonically rewarding and slightly more monotonous, with “slightly” being defined as less than 2-point decreases on the 9-point scales assessing hedonic food ratings and satisfaction with variety. In line with these hypotheses,vertical tower for strawberries the experimental food, as compared to the control food, was rated 1.345 points lower on the hedonic food rating scale and 1.750 points lower on the scale assessing satisfaction with variety. In both instances, these differences between conditions were statistically significant . Consequently, as predicted, the experimental diet was rated as being slightly less hedonically rewarding and slightly more monotonous.I had also hypothesized there would be no significant decline in food satisfaction over the four days. In line with this hypothesis, there was no significant interaction between condition or time and no significant main effect of time on either hedonic food ratings or on satisfaction with variety. Thus, although participants rated the experimental diet as being slightly less hedonically rewarding and slightly more monotonous, the diet did not become less rewarding or more monotonous over time. Because the diet was comprised of long shelf-life, ready-to-eat food, it contained few vegetables and was a relatively sweet, salty diet. Consequently, I had hypothesized that during the experimental condition, as compared to during the control condition, participants would show higher cravings for vegetables, lower cravings for salty food, and lower cravings for sweets. The results showed that, in line with the hypothesis regarding sweets, participants reported lower cravings for sweets while in the experimental condition. However, contrary to my hypotheses regarding cravings for vegetables and salt, there were no significant differences between conditions on cravings for vegetables or salt. In post study interviews, some participants reported they would have liked to have seen more vegetables and more salty food. Unexpectedly, there was a significant interaction between condition and time on cravings for meat, with participants in the experimental condition craving meat significantly more than participants in the control condition on day 2.
Although cravings for meat were not significantly different on the other days of the week, this significant result coincides with participants’ qualitative feedback that they would have liked to have seen more meat in the experimental condition. The experimental condition was designed to be nutritious and highly satisfying, and was therefore expected to meet participants’ psychological needs. Consequently, I had hypothesized that while in the experimental condition, participants would show psychological health that was equivalent to their psychological health while in the control condition, as indicated by no significant differences in mood, perceptions of social disconnection, and perceived stress. I also hypothesized there would be no significant decline in psychological health over the four days, as indicated by non-significant time by interaction terms. In line with these hypotheses, participants showed no significant differences in perceptions of social disconnection, perceived stress, or mood between conditions. There were also no significant differences in perceptions of social disconnection or perceived stress over time. The only mood that changed significantly over time was fatigue; participants reported being less fatigued on the fourth day of each week than they were on the first day of each week. The time term was also significant for the mood of vigor, however pairwise comparisons showed no significant differences on any particular day. Thus, there was no significant decline in psychological health over the four days. The experimental diet was designed to be nutritious, and I had anticipated participants would consume equivalent calories in both the experimental and control conditions. Consequently, I had hypothesized that while in the experimental condition, participants would have physical health that was equivalent to their health while in the control condition, as indicated by no significant differences in sleep or self-reported health and no significant weight loss. I also hypothesized there would be no significant change in self-reported health or weight over time. In line with my hypotheses for sleep and self-reported health, participants showed no significant differences in global sleep scores or self-reported health between conditions, and no significant decline in self-reported health over time. However, contrary to my hypothesis for weight, participants in the experimental condition lost significantly more weight than participants in the control condition. In the control condition, participants lost just 0.071 pounds from Monday to Friday, a change that was not significant. Conversely, in the experimental condition, participants lost 2.157 pounds from Monday to Friday, a change that was statistically significant. Why did participants lose more weight in the experimental condition if they didn’t eat fewer calories? There are many possible explanations. It is possible that participants lost fat mass or lean mass due to eating less in the experimental condition. However, given that there were no significant differences in caloric intake between the two conditions, and that my visual checks of the leftovers showed that participants accurately reported their food intake, this is unlikely. Participants were not asked to record their exercise, and consequently, it is possible that participants exercised more during the experimental week, resulting in weight loss. However, there were no significant differences in vigor or fatigue between the two conditions, and consequently this is also considered unlikely.