Ultra-Processed Foods: What the Biggest Review Yet Actually Found

Evidence: Strong

Ultra-processed foods make up a large share of what many Americans eat every day: packaged snacks, sugary cereals, soft drinks, frozen ready meals and fast food. For years researchers have suspected these foods are bad for health. In 2024, the largest review of the evidence so far put numbers on that suspicion, and the pattern was hard to ignore.

Here’s what the researchers found, how strong the evidence really is, and what it means for your grocery cart.

What are ultra-processed foods?

Most food is processed in some way. Frozen vegetables, canned beans and plain yogurt are all processed, and that’s fine. Ultra-processed foods are different. Researchers commonly use a system called NOVA, which sorts foods into four groups by how much they’ve been industrially changed. Ultra-processed foods sit in the last group.

They’re industrial formulations, typically made from extracted or modified ingredients like refined starches, sugars, oils and protein isolates, plus additives such as colors, emulsifiers, flavors and sweeteners. According to The BMJ, these products tend to be high in added sugar, fat and salt and low in vitamins and fiber.

Common examples

• Soft drinks and sweetened juice drinks
• Packaged chips, cookies and snack cakes
• Sugary breakfast cereals and cereal bars
• Instant noodles and many frozen ready meals
• Hot dogs, chicken nuggets and other reconstituted meats
• Many flavored yogurts, packaged breads and pastries

A quick rule of thumb: if the ingredient list includes things you wouldn’t find in a home kitchen, such as hydrogenated oils, maltodextrin, “natural flavors” or long chemical names, it’s probably ultra-processed. Our Ingredient Decoder breaks down what those names mean.

What the biggest review found

In February 2024, an international team published an umbrella review in The BMJ, one of the world’s leading medical journals. Instead of running one more study, they gathered 45 pooled analyses from 14 review articles, covering nearly 10 million participants, and graded how strong each link was.

Higher intake of ultra-processed food was directly associated with 32 different health outcomes. The researchers rated the evidence as convincing for:

• About a 50% higher risk of death from cardiovascular disease
• A 48–53% higher risk of anxiety and common mental disorders
• A 12% higher risk of type 2 diabetes

They rated the evidence as highly suggestive for a 21% higher risk of death from any cause, a 40–66% higher risk of heart-disease-related death, obesity and sleep problems, and a 22% higher risk of depression.

Notably, the review was not funded by companies involved in producing ultra-processed foods, according to the BMJ Group’s announcement.

Does it prove ultra-processed foods cause harm?

Not on its own, and the authors say so. Observational studies can’t rule out other factors. People who eat a lot of ultra-processed food may also sleep less, exercise less or have less access to fresh food. Some outside experts also noted that parts of the underlying research are weak.

But there’s a reason researchers take the link seriously. In a tightly controlled 2019 trial at the U.S. National Institutes of Health, adults lived in a research clinic and ate either an ultra-processed diet or a minimally processed diet for two weeks each, eating as much as they wanted. On the ultra-processed diet, people ate roughly 500 more calories a day and gained weight. On the minimally processed diet, they lost weight. The meals offered were matched for calories, sugar, fat, fiber and salt.

That doesn’t answer every question, but it shows one clear way these foods may affect health: they’re easy to overeat.

What this means for your cart

The goal isn’t zero. Ultra-processed foods are convenient and sometimes the only realistic option. The research points toward shifting the balance, especially for the foods you eat most often. Here’s a practical approach:

1. Start with drinks. Swapping soda or sweetened drinks for water, sparkling water or unsweetened tea is one of the simplest, highest-impact changes.
2. Fix your most frequent snack. Trade one daily packaged snack for fruit, nuts, plain yogurt or popcorn you make yourself.
3. Read the ingredient list, not just the front of the box. Short lists with recognizable ingredients are a good sign. Our guide to decoding labels can help.
4. Cook a few more meals from scratch. Even simple meals like eggs, rice and beans or a sheet-pan dinner are minimally processed.
5. Keep easy staples on hand. Frozen vegetables, canned beans, oats and plain frozen fruit are processed, but not ultra-processed, and they make quick meals easier.

The bottom line

The largest review to date found consistent links between ultra-processed foods and dozens of health problems, from heart disease to anxiety, and a controlled trial suggests these foods make it easy to eat more than we need. You don’t need to be perfect. Focus on the ultra-processed foods you eat most often, swap a few for whole or minimally processed options, and build from there.

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Sources

1. Lane MM, Gamage E, Du S, et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024;384:e077310.
2. BMJ Group. Consistent evidence links ultra-processed food to over 30 damaging health outcomes. February 2024.
3. Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metabolism. 2019;30(1):67–77.