What are those weird ingredients in our favorite US packaged foods?

<span>‘Ultra-processed foods (or UPFs) are commonly composed of two types of ingredients: industrial food substances and cosmetic additives.’</span><span>Photograph: HannamariaH/Getty Images/iStockphoto</span>
‘Ultra-processed foods (or UPFs) are commonly composed of two types of ingredients: industrial food substances and cosmetic additives.’Photograph: HannamariaH/Getty Images/iStockphoto

If you’ve glanced at a nutrition label lately, you may have found yourself stumbling trying to pronounce ingredients like carboxymethyl cellulose or butylated hydroxyltoluene. In the United States, 73% of the food supply is what researchers would today call “ultra processed” (think chips, sodas, microwave dinners, packaged bread and fast food) – and products are often packed full of those difficult-to-say ingredients.

Ultra-processed foods (or UPFs) are commonly composed of two types of ingredients: industrial food substances and cosmetic additives. While industrial food substances are highly processed versions of ingredients that might otherwise occur in food (proteins, carbohydrates, sugars and oils, for example), cosmetic additives are included to improve the appearance or taste of foods.

Many of these additives have long and difficult-to-pronounce names – but that’s not to say that they’re always dangerous or unhealthy. The preservative ascorbic acid, for example, is just vitamin C. That said, little is known about the health impacts of additives that are often used to make otherwise non-nutritious food impossible to put down. Through precise engineering, corporations use a combination of emulsifiers, thickeners, colorings, flavorings and preservatives to give foods high in sugar, salt and saturated fat the perfect texture, appearance and taste.

Here are some of those ingredients that you’re likely to encounter on your next trip to the grocery store – and what we know about the health impacts associated with them.

Industrial food substances

Sugars and sweeteners are ubiquitous in the US food supply. From sugars like corn syrup, cane sugar, maltose and dextrose to sweeteners like aspartame, sucralose and stevia, these ingredients make ultra-processed foods hyper-palatable and hard to put down. While sugars on their own are found in nature, very high amounts of them (in combination with other additives) are a signal of ultra processing.

Hydrogenated oils are liquid fats that manufacturers add hydrogen to in order to create a solid fat. Fully hydrogenated oils are composed primarily of saturated fats, but “partially hydrogenated” oils contain more dangerous trans fats. Fortunately, the US Food and Drug Administration banned partially hydrogenated oils in 2018 – so all labels today that say “hydrogenated oil” should refer only to fully hydrogenated oils.

Maltodextrin is a highly processed carbohydrate generally extracted from rice, corn, wheat or potato starch. It’s common in lots of foods, and you’ll likely spot it in salad dressings, puddings, soups, energy drinks and frozen dinners.


Emulsifiers keep oil and water components from separating in processed and packaged foods – thereby smoothing out their consistency and extending their shelf lives. A good example is found in most chocolate: emulsifiers keep the cocoa solids and sugars from separating out from the cocoa butter (though in high-quality chocolate, companies just use more and better-quality cocoa butter). Some of the most commonly used emulsifiers include soy lecithin, mono- and diglycerides, polysorbates and sorbitan monostearate.

Lecithin is a fatty substance that occurs in both plants and animals – its defining characteristic is that it attracts both oil and water. Soy lecithin (which comes from soybeans) is particularly common, but sunflower lecithin is an increasingly popular alternative for individuals with soy allergies and those who may be wary of genetically modified soy.

Monoglycerides, like those pesky triglycerides your doctor may check for on a lipid panel, are a type of fatty acid, as are diglycerides. Monoglycerides naturally occur in certain seed oils, but are manufactured and added to many other foods (they’re the most common emulsifiers in the United States). Although generally considered safe, they do contain small amounts of trans fats, which – when eaten in large amounts – can increase the risk of heart disease and stroke.

Polysorbates are industrially manufactured from three ingredients: sorbitol (a sugar alcohol often made from corn or tapioca), a fatty acid and ethylene oxide (a flammable, colorless gas). Research has found that polysorbate 80 and other synthetic emulsifiers (like carboxymethyl cellulose) may “profoundly impact intestinal microbiota in a manner that promotes gut inflammation and associated disease states”.

Thickeners are added to improve, or standardize, the texture of foods. They range from the well-known (gelatin, pectin and whey, for example) to the more obscure (like guar gum and carrageenan).

Guar gum is extracted from the guar (or cluster) bean and commonly added to gluten-free foods to mimic the texture of bread (though you’ll find it in yogurt, ketchup, cheese and meat, too). Because it’s high in fiber, many people use guar gum to treat constipation, diarrhea and irritable bowel syndrome – and some research suggests it may also lower cholesterol and blood sugar. In very large amounts, though, guar gum can cause gas and bloating (and in the 1990s, the FDA called a diet pill that contained extremely high levels of guar gum “hazardous”).

Xanthan gum is created through a process of fermentation, and Xanthan gum powder quickly thickens any liquid it’s added to. In food, that thickening reaction creates elasticity and fluffiness; in the body, it thickens digestive juices and slows digestion. That can have the benefit of slowing blood-sugar spikes. But at very high levels (higher than most people consume), Xanthan gum can increase gas and alter gut bacteria.

Carrageenan is a thickener made from red seaweed and has been used in some parts of the world since as early as 600 BCE (it rose to popularity in processed foods only as recently as the 1950s). Some research suggests that carrageenan may cause inflammation in the digestive tract.

Colors are added to many ultra-processed foods to improve their appearance. These range from natural colorings – like grape-skin extract and saffron – to a range of artificial colors, like FD&C Green No 3 and Citrus Red No 2. Artificial food dyes are made from synthetic, petroleum-based chemicals – the most commonly used are Red No 40 and Yellow No 5. In October 2022, the food policy watchdog group the Center for Science in the Public Interest petitioned the FDA to ban FD&C Red No 3, citing research that showed the dye causes cancer. (CSPI also created a food-additive safety ratings database to help consumers navigate these ingredients.)

In October 2023, California became the first state in the US to ban the manufacture or sale of food containing Red No 3.

Preservatives like salt, vinegar and alcohol have been used to safely extend the lifespan of foods for hundreds of years. In more recent years, other preservatives have been employed to keep foods from spoiling – no small feat for protecting consumer health – like ascorbic acid (vitamin C), sodium benzoate, tocopherols (vitamin E) and nitrites. A few with lengthier names – butylated hydroxyanisole (BHA) and butylated hydroxyltoluene (BHT), for example – have drawn the most attention in recent years. Although both are anti-oxidants, with some health benefits if consumed in moderation, BHA was shown to be carcinogenic in rats and may be an endocrine disruptor in humans.

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