Warning labels are significantly more effective than other food label designs at helping people identify unhealthy packaged foods, according to a 2026 randomized controlled trial of over 2,000 Bangladeshi adults and teenagers. When people saw warning labels, 68-73% correctly identified products high in sugar, sodium, or unhealthy fats, compared to only 14-15% without any label. This finding suggests countries should implement mandatory warning labels to help consumers make healthier food choices.
A major study in Bangladesh tested four different types of food labels to see which one best helps people understand which packaged foods are unhealthy. Researchers showed adults and teenagers different label designs on fake food packages and measured how well they could identify unhealthy products and whether they wanted to buy them. Warning labels, simple red symbols that say “WARNING”, worked best, helping people correctly identify unhealthy foods about 70% of the time, compared to only 15% without any label. According to Gram Research analysis, this finding suggests that countries like Bangladesh should use warning labels on packaged foods to help people make healthier choices and reduce diet-related diseases.
Key Statistics
A 2026 randomized controlled trial of 2,000+ adults and teenagers in Bangladesh found that warning labels helped 68-73% of people correctly identify unhealthy packaged foods, compared to only 14-15% without any label.
According to research reviewed by Gram, warning labels reduced adults’ intention to purchase unhealthy products more effectively than four other label formats tested, including health star ratings and traffic light labels.
In the Bangladesh study, warning labels generated the strongest psychological responses, with 85%+ of participants rating unhealthy foods as unhealthy and showing high support for mandatory labeling policies.
Multiple traffic light labels (using red, yellow, and green colors) achieved 62-65% correct identification of unhealthy foods, making them the second-most effective label type but still significantly less effective than warning labels.
The Quick Take
- What they studied: Which type of food label design best helps people understand which packaged foods are unhealthy and decide not to buy them.
- Who participated: Over 2,000 teenagers (ages 10-18) and adults (ages 19-60) from all regions of Bangladesh, representing the country’s population.
- Key finding: Warning labels helped people correctly identify unhealthy foods 68-73% of the time, compared to only 14-15% without any label. This was much better than other label types tested.
- What it means for you: If your country uses warning labels on unhealthy foods, you’ll find it much easier to spot which products are high in sugar, salt, or unhealthy fats when shopping. This can help you and your family make healthier food choices.
The Research Details
Researchers conducted a randomized controlled trial, which is the gold standard for testing whether something actually works. They divided over 2,000 people from all 8 regions of Bangladesh into 5 groups. One group saw packaged foods with no labels (the control group), while the other four groups saw the same foods with different types of labels: warning labels (red symbols with warnings), health star ratings (stars showing how healthy a food is), traffic light labels (red, yellow, and green colors), or guideline daily allowance labels (showing percentages of daily nutrients).
Each person looked at fake packaged foods and had to answer questions about whether the products were unhealthy and whether they would buy them. The researchers measured how many people correctly identified unhealthy foods, how much they thought the foods were unhealthy, and how much they supported using these labels on real foods.
This study design is powerful because randomly assigning people to different groups helps ensure that any differences in results are actually caused by the labels, not by differences between the groups themselves.
Testing different label designs in a real population is crucial because what works in one country might not work in another. Bangladesh has high rates of diet-related diseases like diabetes and heart disease, so finding the most effective label design could help millions of people make better food choices. This study was also carefully registered before it started, which means the researchers committed to their plan in advance and couldn’t change their methods based on results.
This is a high-quality study because it used a randomized controlled trial design, included people from all regions of Bangladesh (making results representative of the whole country), and tested the labels on both teenagers and adults. The researchers also measured multiple outcomes, not just one thing. The study was preregistered, meaning they published their plan before collecting data, which prevents researchers from cherry-picking favorable results. The only limitation is that the study used fake packaged foods in a research setting, not real shopping situations.
What the Results Show
Warning labels were dramatically more effective than all other label types. When people saw warning labels, 68-73% correctly identified unhealthy foods, compared to only 14-15% in the control group with no labels. This 4-5 times improvement was statistically significant, meaning it’s very unlikely to have happened by chance.
Multiple traffic light labels (which use red, yellow, and green colors) were the second-best option, with 62-65% correct identification. However, they were still noticeably less effective than warning labels. Health star ratings and guideline daily allowance labels performed better than no label but worse than warning labels and traffic light labels.
Warning labels were also most effective at reducing adults’ intention to purchase unhealthy products. People who saw warning labels were much less likely to say they would buy the unhealthy foods compared to people in the control group.
All four label types improved how people felt about the foods compared to no label. People rated unhealthy foods as more unhealthy when they saw any label, and they were more concerned about health. However, warning labels created the strongest feelings of concern and the strongest belief that the labels were effective.
Beyond just identifying unhealthy foods, the study measured psychological responses. Warning labels made people feel the most concerned about health and made them think the labels were most credible and effective. People also showed more ‘cognitive elaboration,’ which means they thought more deeply about the health information when they saw warning labels. Additionally, warning labels received the strongest support from participants, people were most likely to say they wanted these labels on real foods in stores.
These findings align with research from other countries that have tested warning labels. Studies from Chile, Mexico, and other countries have also found that warning labels are more effective than other label types at helping people understand which foods are unhealthy. However, this is one of the first large-scale studies testing multiple label types in South Asia, so it provides important evidence for the region.
The study used fake packaged foods in a research setting rather than real shopping situations, so results might be somewhat different in actual stores where people are making real purchasing decisions. The study also didn’t follow people over time to see if warning labels actually change their long-term eating habits, it only measured immediate reactions. Additionally, the study was conducted in Bangladesh, so results might differ in other countries with different cultures and food systems.
The Bottom Line
If you’re involved in food policy or public health, this research provides strong evidence (high confidence) that warning labels should be used on packaged foods high in sugar, sodium, saturated fat, or calories. If you’re a consumer, look for warning labels on packaged foods, they’re the clearest way to identify unhealthy products. If you’re a parent, teach children to recognize warning labels on foods.
Government officials and health policymakers in Bangladesh and other South Asian countries should prioritize implementing warning labels. Food companies should prepare for potential labeling requirements. Parents and educators should care about this because it affects children’s ability to make healthy food choices. Anyone concerned about diet-related diseases like diabetes and heart disease should support warning label policies.
The benefits of warning labels should be visible immediately, people will make better choices the first time they see the labels. However, the full public health benefits (reduced disease rates) would take years to appear as eating habits change across the population.
Frequently Asked Questions
What type of food label helps people identify unhealthy foods best?
Warning labels are most effective, helping 68-73% of people correctly identify unhealthy packaged foods. This is 4-5 times better than no label and significantly better than health star ratings or guideline daily allowance labels.
Do food warning labels actually change what people buy?
Yes, according to this Bangladesh study, warning labels reduced adults’ intention to purchase unhealthy products more than other label types. People were significantly less likely to say they would buy foods with warning labels.
Which countries should use warning labels on packaged foods?
This study provides strong evidence for Bangladesh and other South Asian countries. Research from Chile and Mexico shows similar results, suggesting warning labels work across different cultures and food systems.
How quickly do warning labels help people make healthier choices?
The benefits are immediate. In this study, people correctly identified unhealthy foods the first time they saw warning labels, suggesting consumers can quickly learn to use these labels when shopping.
Are warning labels better than colorful traffic light labels?
Yes, warning labels significantly outperformed traffic light labels. Warning labels achieved 68-73% correct identification versus 62-65% for traffic light labels, making them the most effective option tested.
Want to Apply This Research?
- Track the number of packaged foods you purchase each week that have warning labels versus those without. Set a goal to increase the percentage of labeled products you buy, aiming for 80% of packaged foods to have warning labels within 3 months.
- When shopping, use the app to scan packaged foods and check if they would have warning labels based on their sugar, sodium, and saturated fat content. Avoid products that would qualify for warning labels, or choose lower-labeled alternatives.
- Weekly check-ins to review which labeled foods you purchased and how many unhealthy products you avoided. Track your confidence in identifying unhealthy foods over time as you become more familiar with label meanings.
This research describes the effectiveness of different food label designs in helping people identify unhealthy foods in a research setting. While the findings are promising, this study used fake packaged foods rather than real shopping situations. Results may differ in actual stores. Before making major dietary changes based on food labels, consult with a healthcare provider or registered dietitian, especially if you have existing health conditions. Food labels should be one tool among many for making healthy choices, including reading ingredient lists and consulting nutrition professionals.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
