Food and mood: A nutritional and mood assessment of a 30-day vegan space diet A. Olabi a,⇑ , D.A. Levitsky b , J.B. Hunter c , R. Spies d , A.P. Rovers b , L. Abdouni a a Nutrition and Food Sciences Department, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon b Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, NY 14853, USA c Biological and Environmental Engineering, Cornell University, 218 Riley-Robb, Ithaca, NY 14853, USA d School of Hotel Administration, Cornell University, 249A Statler Hall, Ithaca, NY 14853, USA article info Article history: Received 8 April 2014 Received in revised form 10 September 2014 Accepted 12 September 2014 Available online 28 September 2014 Keywords: Vegan Space diet Weight Mood Vigor Fatigue abstract The purpose of this study was to examine the effects of eating a total vegan ‘‘space diet’’, ad libitum, on nutrient intake, weight and mood in a group of 16 non-vegetarians. The 10-day diet was repeated three times within the 30 day study. A weekly mood questionnaire was administered to the 16 subjects of the study and to a control group prior, during and post consumption of the vegan diet. Consumption of the diet produced a mean weight loss of 1.7 kg. In addition, two mood factors changed significantly between the pre-study, study and post-study periods: vigor and fatigue. The effect of the diet on mood appeared to be more related to the weight loss than to the effects of diet. The nutritional profile of the diet was sat- isfactory with the exception of its low calcium level and high fiber level. Ó 2014 Elsevier Ltd. All rights reserved. Introduction This study is part of a project aimed at the optimization of a diet for a bioregenerative life support system on the lunar or Martian surface. The high closure bioregenerative diet scenario adopted for this project depended mostly on crops produced in a hydro- ponic station on the Martian planetary surface. The optimization of the diet was based on several factors, including acceptability, variety, astronauts’ specific nutritional requirements and low cost, in addition to macronutrient and micronutrient balance (Smith & Zwart, 2008). A list of 220 previously developed and tested foods was used as a pool for devising the 30-day diet (Hunter, Olabi, Spies, Rovers, and Levitsky, 1999 and Waters, Olabi, Hunter, and Dixon, 2002). A closed diet study was suitable for assessing con- sumption and its related nutritional intake and for examining the effect of the diet on the subjects’ weights, mood and sense of well-being. Vegan diets are usually nutritionally adequate in dietary fiber, carbohydrates, folic acid, vitamin C, vitamin E and magnesium. However, they are typically low in protein, saturated fat, and of particular concern calcium, vitamin B12 (Key, Appleby, & Rosell, 2006) and vitamin D since major sources are animal products (Crowe et al., 2010). It is essential for space travelers to receive adequate nutrition due to their exposure to a closed food system and to environmental factors (Smith & Zwart, 2008); posing chal- lenges to maintaining energy, sodium, potassium, water require- ments (Lane & Feeback, 2002) and vitamin D (Smith & Zwart, 2008). Water, energy and potassium requirements do not differ from the recommended levels on Earth; however, sodium should be reduced because high intakes are associated with increased uri- nary calcium excretion (Lane & Feeback, 2002), and vitamin D remains a challenge for space travelers despite supplementation due to the lack of sunlight exposure which is essential for vitamin D synthesis (Smith & Zwart, 2008). A change from a typical omnivorous American diet to a totally vegan diet could be a source of concern to the space program due to several reasons: weight loss, low acceptability of vegan foods and effect on mood. People who consume a vegetarian diet consume fewer calories and have a reduced body weight (Tonstad, Butler, Yan, & Fraser, 2009). A loss in body weight could have negative effects on the physical performance of astronauts. Vegetarians tend to have a lower BMI than non-vegetarians (Tonstad et al., 2009) despite the fact that obesity is present among some vegetarians Jebb, Rennie, and Cole (2004) and Shetty (2002). A low-fat vegan diet has been shown to result in significant mean http://dx.doi.org/10.1016/j.foodqual.2014.09.003 0950-3293/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Nutrition and Food Sciences Department, 315 FAFS, American University of Beirut, Riad El Solh, 1107 2020 Beirut, Lebanon. Tel.: +961 1 374374x4500; fax: +961 1 744460. E-mail address: ammar.olabi@aub.edu.lb (A. Olabi). Food Quality and Preference 40 (2015) 110–115 Contents lists available at ScienceDirect Food Quality and Preference journal homepage: www.elsevier.com/locate/foodqual