Doctor of Philosophy / Human Nutrition / Edgar Chambers IV / Understanding “why people eat what they eat” is important for improving the lives of people around the world by helping provide industrial and social solutions for people so that they may have greater pleasure and health from the foods they choose. The objectives of the research were to investigate motivations behind everyday meals and choices of different food groups using three different approaches incorporating two psychological perspectives: top-down and bottom-up. The first approach was the Eating Motivation Survey (TEMS) targeting the specific choices of foods and beverages people consumed at specific eating events (breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner, and late-night snack). The second approach was the Food Choice Map (FCM) technique to explore motivations for individual food choices for all eating within a typical week. These two approaches employed the bottom-up process. The last approach used TEMS to investigate food choice directly for six eating occasions, without information about what were eaten specifically. This procedure demonstrated a top-down process because people first thought about their eating as a whole and then read through all TEMS scales to find the motivations that they consider "appropriate" for their answers. The first surveys were completed by 198 participants. The FCM interview was conducted on 100 respondents and the same respondents also participated in the last approach. Data were analyzed by Correspondence Analysis. Liking was the strongest motivation that drove people’s food choice. In addition, need and hunger, habits, price, and convenience were the other main motivations for breakfast, lunch, and dinner while health and weight control were found to be the main driving factors for mid-morning and mid-afternoon snacking. Late-night snacks were linked to pleasure and visual appeal. For dinner, people also were motivated most by variety seeking and traditional eating. Different food groups were also chosen with different motivations. Grain, pasta, meats and poultry were linked to convenience, variety seeking, traditional eating, and price while nuts, seeds, eggs and dairy were associated with need and hunger, health, and weight control. Findings from this project advanced and reinforced the knowledge about food choice and encouraged investigating food choice from different perspectives.

The purpose of this research was to develop, validate, and test an instrument to evaluate motivations to eat in low-income women during the early postpartum period. The instrument was also used in a sample of young college women to further validate the measure and explore determinants of eating in this population. In study 1, the Eating Stimulus Index was validated in 179 low-income women in early postpartum. Validity and reliability were determined via principal components analysis, internal consistency reliability, and test-retest reliability using a subgroup of 31 low-income new mothers. The factor analysis produced an eight factor structure with reliability coefficients ranging from 0.54-0.89. Convenience eating (r=-0.25, P<0.01), emotional eating (r=-0.17, P<0.05), and dietary restraint (r=-0.21, P<0.01) were significantly related to weight status. In study 2, the relationship between eating motivations and diet quality, determined via the Dietary Guidelines Adherence Index, was established in 115 low-income women in early postpartum. High diet quality was related to fruit and vegetable availability (r=0.25, P<0.01), convenience eating resistance (r=-0.36, P<0.001), and vegetable taste preference (r=0.23, P<0.05). Motivations to eat differed between overweight and obese women with the primary motivation being convenience eating and taste, respectively. In study 3, determinants of weight loss were examined in 58 low-income women in early postpartum participating in an 8-week weight loss intervention. Participants were evaluated at pre- and post-study for all measures. Factors related to weight loss included increases in dietary restraint, weight management skills, and weight loss self-efficacy and decreases in fruit juice servings, total energy, and discretionary energy intakes. After hierarchical regression analysis, improvement in weight loss self-efficacy was the most significant determinant (β=0.263, P<0.05) followed by decreases in discretionary energy intake (β=-0.241, P<0.05). In study 4, determinants of diet quality were assessed in a sample of 88 young college women using the Eating Stimulus Index. Low diet quality was associated with poor fruit and vegetable availability, convenience eating resistance, vegetable taste preference, and weight management self-efficacy, while high diet quality was related to increased frequency of meals prepared at home and decreased frequency of meals consumed at fast food restaurants. / text