Grocery Delivery and Healthy Weight Gain Among Low-income Pregnant Young Women

The overall aim of this study is to determine whether an intervention that facilitates receipt of healthy food and unsweetened beverages will promote healthy weight gain and improve diet quality among pregnant young women age 14-26 living in Michigan. This hypothesis will be tested in a three-arm randomized controlled trial (RCT) using a parallel design; Arm 1: Usual WIC (Control), Arm 2: Usual WIC + Delivery of WIC-approved food, Arm 3: Usual WIC + Delivery of WIC-approved food PLUS unsweetened beverages. Three arms are necessary because our goal is to make three distinct comparisons. First, we need to determine the effect of food delivery (Arm 2) compared to usual WIC (Arm 1). Second, we need to determine the combined effect of food plus unsweetened beverage delivery (Arm 3) compared to usual WIC (Arm 1). Finally, we need to evaluate the effect of food delivery (Arm 2) compared with food plus unsweetened beverage delivery (Arm 3) to determine the individual impact of replacing SSBs, a major contributor to excessive pregnancy weight gain in our population. Our study does not assess the impact of delivering only unsweetened beverages compared to usual WIC because the potential policy implication is the delivery of WIC benefits. A widespread program that only delivers unsweetened beverages is not likely.

Upon completion of baseline screening and assessments, 570 pregnant young women will be randomly assigned to either the control group or one of the two experimental groups. Enrollment in the study is rolling and starts as early as possible in the pregnancy (must be before 21 weeks gestation). The intervention period begins at enrollment and continues to the end of pregnancy/birth. Thus, each participant will be enrolled for approximately seven months post-randomization. During the intervention period, all groups will receive usual WIC food, nutritional assessment, and counseling benefits, including monthly intensive nutritional counseling sessions based on a state-approved curriculum with trained nutritionists and peer counselors.

• The control group (Arm 1) will receive usual WIC counseling and food benefits loaded onto their electronic benefits card (EBT) for them to use in person at approved grocery stores.
• The first experimental group (Arm 2) will receive usual WIC counseling and food benefits, as well as twice-monthly home deliveries of WIC-approved foods.
• The second experimental group (Arm 3) will receive usual WIC counseling and food benefits as well as twice-monthly home deliveries of WIC-approved foods PLUS unsweetened beverages to replace their current SSB intake.

The primary outcome is weight gain during pregnancy as defined by the Institute of Medicine (IOM)/National Academy of Medicine (NAM) Guidelines. Secondary outcomes include Healthy Eating Index (HEI) scores and dietary intake of fruits, vegetables, whole grains, and SSBs; infant birth weight; and prenatal and delivery complications identified through postpartum medical record review (e.g., small/large for gestational age, gestational diabetes, hypertensive disorders, operative delivery).