High concern

High fructose corn syrup

HFCS · HFCS-55 · HFCS-42 · "corn sweetener"

An industrial sweetener made by enzymatically converting cornstarch into fructose and glucose. Cheaper than sugar, sweeter than sugar, and ubiquitous in American processed food since the 1980s.

Why we flag it

HFCS isn't chemically that different from table sugar — both are roughly half glucose and half fructose. The honest concern isn't that HFCS is uniquely poisonous; it's that HFCS made cheap sweetness possible at a scale that has remade the food supply. American per-capita added-sugar consumption roughly doubled in the decades after HFCS replaced cane sugar in soda and processed foods, and that excess is strongly associated with obesity, type 2 diabetes, fatty liver disease, and metabolic syndrome.

There's also some evidence that the unbound fructose in HFCS may be metabolized slightly differently than the fructose-glucose bond in sucrose — but the bigger story is dose. When HFCS is in your bread, ketchup, salad dressing, and yogurt, the cumulative load adds up fast.

Where you'll find it

Nearly any processed food product where sweetness or shelf-stability matters:

What to look for instead

The cleanest answer is to eat fewer sweetened processed products overall — but when you do want sweetness, less-refined options carry more flavor and a bit more nutrition:

The clearest label signal is the absence of corn syrup of any kind on the ingredient list, paired with USDA Organic certification — which prohibits HFCS outright.