This app is trying to change how people eat

The Star

10-06-2025

Cheez-Its used to be one of Marissa Gradei's go-to snacks, in part because she thought of them as 'healthier' alternatives to other savory nibbles such as potato chips.
That changed three months ago, when Gradei, 27, a social media manager in Fairfax, Virginia, started using a smartphone app called Yuka. The app prompts users to scan the bar codes of food and personal care items – in grocery stores and at home – and then offers a score out of 100 to indicate how 'healthy' it thinks the item is for you or the environment.
Gradei's trusty snacks scored a 2 out of 100 – 'bad' for health, according to the app. She hasn't purchased any since.
After the Yuka app launched in the United States in 2022, more than 20 million people have downloaded it – a figure that has more than doubled since January 2024. In a recent interview with CNN, Health Secretary Robert F. Kennedy Jr. said he and his wife 'consider it invaluable'.
'You can go into any grocery store, flash it at any product, and you can get a 'go' or a 'no',' he said.
But can the Yuka app accurately portray how good a given food is for your health? And should you rely on an app to guide your food choices in the first place? We asked four nutrition experts.
How does it work?
The Yuka app originally launched in France in 2017 as a tool to help people quickly understand the healthfulness of certain food and personal care products. It expanded to the United States in 2022.
After scanning a product's bar code, the app assigns the product a health value out of 100 – with 100 being the best – and a corresponding colour score of excellent (dark green), good (light green), poor (orange) or bad (red).
To generate these scores for certain foods, the app uses an algorithm based on three criteria: the food's nutritional quality (60% of the score), the presence of additives and whether the app deems the additives risky (30%) and whether the food is organic (10%).
Yuka uses a European labeling system called Nutri-Score to assess a food's nutritional quality. High protein and high fiber are good, for example; high amounts of sugar, sodium, saturated fats and calories are bad.
The company has two full-time employees – one with a toxicology background and one with a food engineering and human nutrition background – who sort through the scientific research on about 600 food dyes, preservatives, thickening agents, artificial sweeteners and other food additives. They classify them as 'high risk', 'moderate risk', 'limited risk' or 'risk-free' based on their potential links to health conditions such as cancer, heart disease, attention-deficit/hyperactivity disorder and infertility.
The app is free, although it offers a premium version for between US$10 (RM42) and US$50 (RM211) per year, said Julie Chapon, one of Yuka's co-founders. The premium version includes extra features such as the ability to use the app when your phone is offline.
The company does not promote the app through paid advertisements, or take money from food and cosmetics industries, said Chapon, who has a marketing and consulting background.
Kennedy's endorsement has most likely helped with awareness, she said, but the app isn't affiliated with the Make America Healthy Again, or MAHA, movement.
What do nutrition experts think of Yuka?
The app has hit on a real hunger for more clear-cut nutrition information, said Dr Dariush Mozaffarian, director of the Food Is Medicine Institute at Tufts University. 'The public is really confused about what defines a healthy food,' he said.
And it can be valuable for people to use their smartphones to help them make better food choices, said Lisa Harnack, a professor of public health nutrition at the University of Minnesota.
Anyone can flip over a product and read its nutrition label, she said, but for the average person, it can be burdensome to try to parse the healthfulness of dozens of foods at a time. Scanning a product and glancing at its ranking and color score is much simpler.
That said, some experts worry that labelling food as either 'good' or 'bad' can lead to disordered eating.
'I don't like that,' Elaine Siu, a dietitian at the City of Hope cancer center in Duarte, California, said of the labeling system. Instead, she said, people should focus on following a balanced diet overall. This typically involves eating plenty of fruits, vegetables, whole grains, lean sources of protein and healthy fats.
And keep in mind that your nutritional needs will vary depending on your health and activity levels, she said, which the Yuka app can't account for.
Siu, for instance, advises cancer patients on how to eat. Many are undernourished and could benefit from consuming more calories. But the Yuka app deducts points for high-calorie foods.
Several of Siu's patients have refused to drink the nutrition shakes or eat the protein bars she has recommended, she said, because the Yuka app has scored them poorly.
Is its rating system trustworthy?
The Nutri-Score system that Yuka uses to assess a food's nutritional quality is an 'OK' system, Mozaffarian said. He said he doesn't agree with the idea of penalising foods for calories, since many high-calorie foods can be nutritious. The app labels many nuts and nut butters, for instance, as 'too caloric'. And, Mozaffarian said, it's problematic that Yuka doesn't distinguish between natural sugars and added sugars – the latter of which are most concerning for health.
Because there's still a lot we don't know about how food additives affect us, Mozaffarian said, it's 'a little excessive' to devote 30% of the score to their presence.
Much of the research Yuka uses to assess the risk level of additives are either observational studies – which can't demonstrate cause and effect – or animal studies that use much higher doses of those additives than what you'd find in food. Animal study results also don't always translate to humans.
Siu said she was surprised to see monosodium glutamate, or MSG, categorised as 'high risk'. Although some limited studies have linked the ingredient to conditions such as heart disease and Type 2 diabetes, the amount we normally consume in food has not been shown to cause harm, she said.
Siu said she recently used the app on a package of seaweed sheets that contained just 10 calories per serving, and it ranked the product as 'too high' in calories. 'The scoring system is very questionable,' she said.
Of the four experts we consulted, none agreed with Yuka's decision to include a food's organic classification in its scoring system.
There's no proof of any nutritional benefit from eating organic foods relative to conventionally grown foods, said Melanie Hingle, a professor of nutritional sciences at the University of Arizona.
What's the bottom line?
The experts largely agreed that it could be beneficial to limit highly processed foods, to which the Yuka app typically gives low scores. Eating unprocessed, whole foods – such as fruits, vegetables, nuts, legumes and whole grains – is associated with reduced risks of various chronic conditions such as Type 2 diabetes, heart disease and some cancers.
But you don't necessarily need an app to help you do that. And whole foods typically don't have bar codes you can scan anyway.
'Ideally, the app would include foods that don't come in packages,' Harnack said. 'If these types of foods are missing, it might be easy to overlook some of the best choices in the supermarket.' – ©2025 The New York Times Company
This article originally appeared in The New York Times.