You notice them more and more in the supermarket, and there is a good chance that you are like them too: Careful and probing consumers. You make sure to read the ingredient list and compare the nutritional facts tables between products. But even skilled, nutrition–conscious and health–minded consumers make a large portion of their purchasing decisions within seconds, long before they have read a single line on the back.
The mechanism operates through two parallel channels. The first is explicit text on the packaging – “Rich in fiber", “Enriched", “No added sugar", “Organic". These statements consistently improve how the product is perceived from a health perspective, even when they are technically correct but not always relevant. The second channel is quieter and operates without words: Green packaging color, an illustration of grain stalks or leaves, minimalist design, delicate lettering.
Together, the two channels create what researchers call the "health halo effect": One positive detail causes the brain to attribute positive qualities to the entire product, and to fill in the rest of the information without checking. A granola bar in green packaging with the caption "rich in fiber" can contain more sugar than a chocolate chip cookie, and still be perceived as the healthier option.
A systematic review conducted by two researchers, Steiner and Florack, from the University of Vienna revealed several interesting conclusions. The review, published in the journal Foods in 2023, found that packaging color alone affects the consumer's perception of health – Usually in favor of green, although the intensity of the effect varies between food categories.
Another study by Mediano Stoltze from the University of North Carolina, published in the journal Appetite in 2021, revealed that mentioning the term "dietary fiber" significantly improved the health perception of breakfast cereals, even when dealing with products of low nutritional quality according to accepted criteria. Even when red warning labels for sugar or fat were added alongside the mention, the effect weakened but was not eliminated.
The World Health Organization (WHO) recommends front–of–package nutritional labeling as an effective policy tool to encourage healthy choices, and recognizes several approaches: Warning labels for excessive ingredients (sugar, sodium, saturated fat) and colored traffic light systems, among others, to help consumers clearly understand the nutritional composition of the food they buy.
In Israel, the front–of–package nutritional labeling regulation has been active since 2020. Products that exceed the threshold for sodium, sugar or saturated fat carry a red label. Products that meet health criteria are eligible for a green label. A Ministry of Health survey, published in the International Journal of Food Sciences and Nutrition in 2022, found that a high percentage of the public recognizes the labels and reports using them when shopping. In response to the reform, manufacturers acted in two pathways: They changed recipes to avoid red labeling, and added positive statements alongside the label, such as “sugar from fruit only", which were designed to weaken the intensity of the message.
“Free of" – not what you thought
Claims of the type “no added sugar" or “gluten–free" are often perceived as a sign that the product is healthier, even though their nutritional significance is limited. Thus, for example, a “gluten–free" product is not necessarily healthier for people who do not have celiac disease or gluten sensitivity. Sometimes it contains more sugar, starches or food additives designed to compensate for the lost texture.
Another example: The claim “no added sugar" can create a misleading illusion. True, white sugar was not added to the product, but sometimes it still contains high amounts of sugars originating from honey, date syrup, fruit concentrate, corn syrup or other ingredients. As far as the body is concerned, some of these products still provide a significant amount of sugar, even if the caption on the front paints a healthier picture. The prominent caption says little about what the product actually provides.
Among parents, the impact of the front of the packaging is even stronger. Parents tend to attribute good nutritional quality to products bearing markings such as “from whole grains", “rich in calcium" or “no food coloring", even when the product contains a high concentration of sugar, salt or fat. A review published in the journal Current Nutrition Reports in 2024 summarized over ten studies on the subject and found that the mere appearance of a single health claim on the packaging caused parents to estimate that the entire product was nutritious.
Another study published in the journal Maternal & Child Nutrition in 2024 examined baby and toddler food products (ages 6 to 36 months) in supermarkets in Australia. More than 75% of the products did not meet international nutritional requirements, mainly due to excess energy (calories) and sugar. None of the products met the World Health Organization criteria regarding marketing claims, including frequent claims of the type “no added sugar", “gluten–free" or “no preservatives", which actually appeared on products with a weak nutritional profile.
So what should you check at the supermarket?
The basic recommendation is to read the ingredient list. This recommendation is correct but not sufficient. The ingredient list is written in descending order of quantity, and therefore the first three ingredients are particularly significant: If sugar, syrup, white flour or oil open the list, the claim on the front can describe one detail out of a product whose main substance is different. The nutrition table expands the information of the ingredient list, but on the condition that we refer to the serving size that we actually eat, not to the one the manufacturer chose to display. A bag with a snack that looks “light" in the values of a 30–gram serving might turn into a 120–gram serving when it includes the entire contents of the bag.
Every design element in the packaging – Color, font, illustration, slogan – Is the product of a marketing decision. The ingredient list and the nutrition table, usually on the back or side of the packaging, are subject to strict regulation, and therefore provide more reliable information than what appears on the front side of the packaging.