How Do School Salad Bars Impact Elementary School Students' Dietary Quality and Energy Intake at Lunch? A Randomized Controlled Plate Waste Investigation.

Children's dietary quality is suboptimal, increasing the risk of numerous chronic illnesses. Salad bars (SBs) have potential to enhance children's nutritional intake within the National School Lunch Program (NSLP); yet, empirical support is lacking. To address this gap, we evaluated the impact of school salad bars on dietary quality and energy intake at lunch. Seven matched elementary school pairs were randomly selected. All schools served pre-portioned fruit and vegetables (F&V) at baseline. Within each pair, one school received an SB. Digital imagery plate waste methods were applied at baseline and 4-6 weeks post salad bar installation to determine intake (20% increments for food, ounces for beverages). Dietary quality (Healthy Eating Index (HEI-2015)) and energy intake (kcal) were evaluated in NDSR. Multilevel modeling evaluated group (SB vs. control) and time (baseline vs. post) differences and group-by-time interactions for: (1) HEI-2015 (total and component scores) and (2) kcal intake (overall, F&V, non-F&V, and beverage kcals). Data from 5674 trays are reported. Significant group-by-time interactions were observed for HEI-2015 total scores and Greens and Beans, Total Fruit, Whole Fruit, Refined Grains, and Added Sugar component scores ( < 0.0001), supporting improved dietary quality in SB schools. SB HEI-2015 scores were 60.1 ± 9.8 at post (+5.3 from baseline; < 0.0001) compared with 57.2 ± 9.5 in controls (+1.0 from baseline; = 0.065). Total energy intake significantly increased in SB schools (376 ± 151 kcal (baseline) → 434 ± 176 kcal (post)), driven by F&V energy (+59 kcal), with no change for controls. Within the NSLP, SBs improved dietary quality and increased energy intake due to increased F&V intake without replacing other foods. Results can inform school nutrition policies designed to reduce chronic illness risk.