High levels of food processing can have detrimental health effects independent of nutrient content. Experts and advocates have proposed adding information about food processing status to front-of-package labeling schemes, which currently exclusively focus on nutrient content. How consumers would perceive “ultraprocessed” labels has not yet been examined. To address this gap, we conducted a within-subjects online experiment with a convenience sample of 600 US adults. Participants viewed a product under three labeling conditions (control, “ultraprocessed” label, and “ultraprocessed” plus “high in sugar” label) in random order for a single product. The “ultraprocessed” label led participants to report thinking more about the risks of eating the product and discouraging them from wanting to buy the product more than the control, despite not grabbing more attention than the control. The “ultraprocessed” plus “high in sugar” labels grabbed more attention, led participants to think more about the risks of eating the product, and discouraged them from wanting to buy the product more than the “ultraprocessed” label alone. “Ultraprocessed” labels may constitute promising messages that could work in tandem with nutrient labels, and further research should examine how they would influence consumers’ actual intentions and behaviors.

Importance: Front-of-package food labels (FOPLs) about nutrient content and health effects are a promising policy to improve diet quality but may also contribute to harmful weight stigma.Objective: To assess whether different types of FOPLs impact perceived weight stigmatization, whether weight-neutral label content mitigates stigmatization, and possible trade-offs between perceived stigmatization and effectiveness.Design, Setting, and Participants: This randomized clinical trial with a between- and within-participant design used a single-exposure online survey conducted from January 18 to 26, 2024. Participants were US adults aged 21 years or older recruited using an online crowdsourcing research platform.Interventions: Participants were randomly assigned 1:1:1:1 to 1 of 4 types of FOPLs applied to sugary beverages: control labels, nutrient warnings (ie, indicating beverages high in calories or added sugar), text-only health warnings, or graphic health warnings (ie, indicating beverages were linked to obesity, diabetes, and tooth decay). In random order, participants viewed 2 versions of their assigned label type differing on whether the content referenced calories and obesity (ie, standard version) or not (ie, weight-neutral version).Main Outcome and Measures: The primary as-treated outcome was perceived weight stigmatization. Secondary outcomes were perceived message effectiveness, attributional judgments of responsibility for weight, and explicit weight bias.Results: A total of 2522 participants completed the experiment (1262 [50%] women; mean [SD] age, 44.3 [15.2] years). Among standard labels, graphic warnings (mean differential effect [MDE], 0.81; 95% CI, 0.71-0.92) and text-only warnings (MDE, 0.41; 95% CI, 0.30-0.51) were perceived as more stigmatizing than control labels, while nutrient warnings were not (MDE, 0.003 [95% CI, −0.10 to 0.11]; P = .96). Weight-neutral labels were perceived as less stigmatizing than their respective standard versions (range: MDE, −0.66 [95% CI, −0.72 to −0.60] for graphic health warnings to −0.08 [95% CI, −0.14 to −0.02] for nutrient warnings). Weight-neutral versions were perceived as less effective than standard versions for nutrient warnings (MDE, −0.11; 95% CI, −0.16 to −0.06) and graphic health warnings (MDE, −0.05; 95% CI, −0.10 to −0.001) but not for text-only warnings. Graphic and text-only warnings did not affect explicit weight bias, while nutrient labels led to a small bias reduction (MDE, −0.08; 95% CI, −0.16 to −0.002).Conclusions and Relevance: In this randomized clinical trial of FOPLs, nutrient warnings performed best compared with other FOPL types at simultaneously maximizing perceived effectiveness and minimizing perceived stigmatization. Labels perceived as more stigmatizing were not consistently perceived as more effective. Removing references to obesity from health warnings reduced stigmatization without meaningfully reducing perceived effectiveness.Trial Registration: ClinicalTrials.gov Identifier: NCT06179043

In Chile, added sugar warning labels prompted product reformulation with nonnutritive sweeteners (NNS). Some countries have since adopted NNS labels to discourage this industry response, but evidence of their effects on consumer behavior is limited. This study aimed to examine the impact of 2 types of NNS labels on Chilean parents' NNS-containing product identification, product choices for their children, and product perceptions. In 2025, 3523 Chilean parents (children age 2-14 y) were randomly assigned to either no NNS label (control), a child-focused NNS warning ("CONTAINS NON-NUTRITIVE SWEETENERS, AVOID CONSUMPTION AMONG CHILDREN"), or an NNS disclosure ("CONTAINS NON-NUTRITIVE SWEETENERS"). Participants viewed sets of 4 products (one without added sweeteners and others with sugar, NNS, or both) and identified NNS-containing products, selected one product for their child, and, afterward, recalled labels seen. Next, participants viewed NNS-containing products and rated labels' perceived message effectiveness (PME), products' perceived healthfulness, and intentions to limit children's NNS intake. Average differential effects (ADEs) are reported in percentage points (pp) or 1 to 5 scales. Both the child-focused NNS warning and NNS disclosure led to higher correct identification of NNS-containing products (ADE = 67 pp; ADE = 69 pp, both P < 0.001), lower selection of NNS-containing products (ADE range: -22 pp to -35 pp; ADE range: -22, -33 pp, all P < 0.001), and higher selection of products without added sweeteners (ADE range: 20-35 pp, ADE range: 22-31 pp, all P < 0.001) than control, respectively. Neither NNS label increased selection of sugar-sweetened products. NNS label recall was 63% for the child-focused NNS warning, and 84% for the NNS disclosure (P < 0.001). Both the child-focused NNS warning and NNS disclosure led to higher PME (ADE = 1.53; ADE = 0.92, both P < 0.001), lower product healthfulness perceptions (ADE = 1.43; ADE = 0.81, both P < 0.001), and higher intentions to limit children's NNS intake (ADE = 0.66; ADE = 0.17, both P < 0.001) than control, respectively. Both NNS labels improved parents' NNS-containing product identification and encouraged choice of products without added sugar or NNS for their children.This trial was registered at the clinicaltrials.gov as NCT06842693. https://clinicaltrials.gov/study/NCT06842693.

Introduction: Ultra-processed foods (UPFs), defined as foods in group 4 of the NOVA classification system, are a key contributor to chronic disease in the United States. Front-of-package warning labels (“warnings”) offer a promising strategy to help Americans reduce consumption of UPFs. Requiring warning labels on UPFs could help reduce consumption of these foods. However, the effects of UPF warnings are largely unknown. The impact of warning labels on UPFs among Latino adults was examined. Study design: Online randomized trial. Setting/participants: 4,107 Latino adults (49% limited English proficiency) in the US. Intervention: Participants viewed one of three labels: control labels displaying barcodes; identity warnings stating “WARNING: Ultra-processed food”; or health warnings stating “WARNING: Consuming ultra-processed food and drinks can cause weight gain, which increases the risk of obesity and type 2 diabetes”. Main outcome measures: Participants viewed four UPF products displaying their randomly assigned labels. Participants indicated whether the product was UPF (primary outcome) and rated perceived healthfulness of the product, intentions to purchase the product, and perceived message effectiveness (secondary outcomes). Results: Identity warnings (70% correct) and health warnings (67% correct) both led to higher correct identification of UPF compared to control labels (54%, p<.001), with the identity warning having a larger impact than the health warning ( p =.007). Compared to the control label, the identity warning and health warning both elicited higher perceived message effectiveness and lower perceptions of healthfulness and purchase intentions ( p <.001 for all outcomes) with no significant differences between UPF labels. The impact of the health warning label (vs. the control label) on correct identification of UPF was greater for participants with high education ( p =0.012) compared to those with low education, and participants with limited English proficiency ( p =0.001). Conclusions: UPF warnings may help consumers identify UPFs and influence product perceptions and intentions. Trial registration: NCT06296355.