High fructose corn syrup, commonly seen as “HFCS” on ingredient labels is a common sugar substitute used in food products. However, fructose has a few negative associations with it for a few reasons. This has caused some consumers to stay away from high fructose corn syrup. Here I dive into what HFCS actually is and whether it even contains that much fructose.

High Fructose Corn Syrup Vs Table Sugar

How Fructose Is Processed By The Body

Fructose is a form of sugar, just like glucose, but there are a few differences in how these sugar molecules are processed by the body. Your muscles can uptake glycogen from glucose far more easily than they can from fructose. Fructose is primarily processed by the liver which means that consuming higher amounts of fructose may place much more stress on the liver. Furthermore, if you’re replenishing energy from exercise with primarily fructose, it’s far less likely to make it into the muscle cells, hence why glucose is a better way to replenish muscle glycogen.

Composition Of HFCS And Table Sugar

As you might guess, high fructose corn syrup probably has a high proportion of fructose in it. However, the term “high fructose” is certainly misleading since HFCS generally comes in 2 forms. HFCS-42 and HFCS-55, each respectively containing 42% or 55% fructose with the rest of the sugar being made out of mostly glucose and a few other carbohydrate molecules. The more common version is HFCS-55 which contains 55% fructose, 41% sucrose and 4% other oligosaccharides. When you compare that to table sugar or sucrose, which has a composition of 50% fructose and 50% glucose, this is highly misleading.

If you’re avoiding HFCS because you’re concerned that it contains far more fructose than table sugar, well, you probably shouldn’t be worried about it since they contain very similar proportions of fructose.

Why Do People Avoid Fructose?

The main reason people avoid fructose is because of some studies linking fructose with negative health outcomes such as decreased insulin sensitivity and increased visceral adiposity although there are other studies and meta-analysis showing that fructose does not appear to promote weight gain when substituted for other carbohydrates in the diet providing similar calories (any increase in weight is attributed to the calorie increase). The main concern is that since fructose is primarily metabolised by the liver, if you consume too much fructose, it will be mostly stored as fat.

Some studies out there performed on mice which have shown issues with fructose such as increased intestinal permeability and intestinal bacterial overgrowth.

Other studies conclude that it’s the fructose causing negative health effects. One I came across suggested it could cause weight gain by placing extra stress on the liver, making it harder to the liver to properly metabolise fat.

Ultimately, it’s up to you to decide whether fructose is something you want to consciously avoid. The studies and data is largely mixed and inconclusive. Choosing table sugar or avoiding HFCS on food packs will probably do very little. In fact, most fruit contains a higher proportion of fructose to glucose so if you want to avoid fructose you’d be better off eating less fruit and less sugar altogether.

Realistically, I don’t think fructose is something to be concerned about, especially if it comes from natural sources. Maybe it’s a concern when it comes in the form of synthetic products, but I don’t know. Some sweeteners such as agave syrup can have a sugar composition of 90% fructose. If you’re concerned about fructose, then that’s the sweetener I would be cautious of.

Thanks for reading! If you found this post informative, I’d appreciate it if you could share it with others!

Further Reading:

What Is Insulin Resistance?

How I Broke Free Of Sugar Dependency

60 Sneaky Names For Sugar

8 Ways To Eliminate Sugar Cravings


Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans

Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity

Effect of fructose on body weight in controlled feeding trials: a systematic review and meta-analysis.

Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women

Fructose Consumption in the Development of Obesity and the Effects of Different Protocols of Physical Exercise on the Hepatic Metabolism

Fructose toxicity: is the science ready for public health actions?

Health implications of fructose consumption: A review of recent data

High Fructose Corn Syrup Questions And Answers – FDA

High-fructose and high-fat diet damages liver mitochondria

Is Agave Worse Than HFCS? – How Stuff Works

Is HFCS Worse Than Sugar – Examine.com

No differential effect of beverages sweetened with fructose, high-fructose corn syrup, or glucose on systemic or adipose tissue inflammation in normal-weight to obese adults: a randomized controlled trial

Toll-like receptor 4 is involved in the development of fructose-induced hepatic steatosis in mice