Investigating Associations between Consumption of Unprocessed and Ultra Processed Foods and Maternal and Neonatal Health Outcomes—Secondary Outcomes of LIFT Trial

Abstract

Investigating Associations between Consumption of Unprocessed and Ultra Processed Foods and Maternal and Neonatal Health Outcomes—Secondary Outcomes of LIFT Trial Kathryn Whyte The ultra-processing of food has become a much more important aspect of dietary patterns and dietary quality in terms of its impact on body weight, diet related diseases, health, and well-being in the past decades. NOVA is a set of guidelines developed that classifies diet quality by degree of food processing. The NOVA guidelines distinguish four categories: unprocessed /minimally processed foods; culinary ingredients; processed foods; and ultraprocessed foods. Numerous studies have found an association of ultra-processed foods and health conditions such as obesity and metabolic syndrome. This study analyzed the associations between maternal diet quality as measured by NOVA and maternal anthropometric and neonatal body composition outcomes. The optimal method of nutrition intervention and education for this special population remains unknown; using NOVA may provide researchers with a different lens to assess diet quality and health care professionals with additional vocabulary to convey more tailored messages regarding optimal nutrition strategies for mother and offspring. Using data collected from a large randomized controlled intervention trial at pre and post intervention, this study aimed to compare the NOVA guidelines assessment of maternal diet quality to the parent study assessment of diet quality, the Healthy Eating Index (HEI), using statistical correlations. Secondly, this study aimed to look at the relationship of ultra-processed food intake to the maternal gestational weight gain experience using a logistic regression. Thirdly, this dissertation aimed to explore the relationship between maternal ultra-processed food intake and neonatal lean mass as measured by quantitative magnetic resonance (QMR) and fat free mass as measured by air displacement plethysmography (ADP: PEAPOD). In terms of maternal outcomes, the study found that NOVA and HEI were significantly correlated at pre intervention but not at post intervention. The odds of gaining excessive gestational weight decreased as maternal ultra-processed food intake increased which was not in the hypothesized direction when using study participant data. However, the odds of gaining excessive gestational weight increased as maternal ultra-processed food intake increased which was in the hypothesized direction when using the Institute of Medicine weight gain recommendations. Also, while obesity did not predict excessive gestational weight gain, those with obesity ultra-processed food intake did predict gestational weight gain. These various inconsistencies are likely due to the instability of the dietary intake data because only one 24 hour dietary recall was obtained from mother. In addition, the mothers’ diets were very healthy to begin with, where ultra-processed food intake formed about 45% of calories both pre and post intervention, when the national average is 57%. Race was also significant predictors of gestational weight gain for the mothers. Being non-white significantly increased the odds of gaining excessively as did the interaction of having obesity and eating more ultra-processed foods. In terms of neonatal outcomes, findings from this study suggest that length and fat mass are significant predictors of lean mass in neonates. In terms of the impact of maternal ultraprocessed food intake, the higher the consumption of ultra-processed food, the greater the neonatal lean mass, which this was not in the hypothesized direction. However, the association was minimal with very small beta weights and regression line, when plotted was quite flat, so that the finding is not clinically meaningful. It remains important to know whether maternal ultra-processed food intake influences gestational weight gain and the body composition of the neonate. Thus, future research should include using similar data analyses on a population with a more nationally representative diet, a larger sample size, and a more robust measure of dietary intake such as three 24-hour recalls. Given that a similar recent study found ultra-processed food to be highly predictive of maternal and neonatal outcomes, and many other studies have demonstrated that ultra-processed food is related to several health conditions in many countries that this study did not measure, it seems prudent for healthcare providers to take advantage of prenatal visits as a window of opportunity to encourage the consumption of unprocessed and minimally foods and help women make informed decisions regarding ultra-processed foods. TABLE OF CONTENTS List of Tables ................................................................................................................................. iv List of Figures ............................................................................................................................... vii List of Acronyms ......................................................................................................................... viii Acknowledgments.......................................................................................................................... ix Dedication ........................................................................................................................................x Chapter I – INTRODUCTION ..................................................................................................... 1 Background: Maternal Diet Quality, Gestational Weight Gain, and Neonatal Outcomes ...................................................................................................................... 6 The NOVA Guidelines .................................................................................................... 10 Purpose of the Study and Specific Aims.......................................................................... 17 Significance...................................................................................................................... 19 Chapter II – LITERATURE REVIEW ........................................................................................ 20 Incidence and Importance of Excessive GWG ................................................................ 20 An Area of Nutrition Intervention Literature With Many Gaps ...................................... 23 Fetal Programming........................................................................................................... 29 Maternal Diet Quality ...................................................................................................... 32 Shifting From Nutrients to a Wider Lens ........................................................................ 39 Comparison With Dietary Quality Indices (HEI/AHEI/DASH/aMED) .......................... 59 Chapter III – METHODS............................................................................................................. 71 Study Setting .................................................................................................................... 73 Source of the Data ............................................................................................................ 73 The LIFT Parent Study ........................................................................................... 73