Sugar is Sugar is Sugar  —  Part 1 – Watts Up With That?

Guest Essay by Kip Hansen — 26 July 2025 — 1700 words

“High-fructose corn syrup ‘is just a formula for making you obese and diabetic,’ RFK Jr. has said.” [ source ]   That’s the narrative in the Wild and Wacky World of Nutrition.  It is based on the ever-present, ubiquitous, error of mistaking association and time-coincidence with causation.

“In 2004 Bray et al ( link ) published the hypothesis that HFCS is a direct causative factor for obesity. They based their hypothesis on a temporal relation between HFCS use and obesity rates between 1960 and 2000.” [ source ]

In that paper, this is the money graph:

[Extra points to readers who can see what was omitted from this graph – which omission substantially negates Bray’s hypothesis. ]

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High-fructose corn syrup (HFCS) is just sugar.

When we use the word “sugar” in everyday language, what do we mean?  Most of us mean “table sugar” – what white granular sugar that is in our sugar bowls, or comes in little packets at the café or in 5 pound bags from the grocery store. 

And what is “table sugar”?  It is sucrose.  

There are lots of sugars in the natural world.  A “ sugar”, in biochemistry, is “any of the class of soluble, crystalline, typically sweet-tasting carbohydrates found in living tissues and exemplified by glucose and sucrose.”   There are several more sugars commonly found in foods:  fructose, lactose, maltose, galactose.   

Here’s a rundown of the most common sugars that humans ingest in their diets:

Sucrose:  Chemical Formula – C₁₂H₂₂O₁₁

This is our common white table sugar.  It is the most used sweetener in foods and beverages.  Sucrose is a compound sugar, a disaccharide,  consisting of exactly 50% fructose and 50% glucose, one molecule of each bonded together.

Glucose:  Chemical Formula – C₆H₁₂O₆

                        Glucose is the most important source of energy in all organisms.  Glucose circulates in the blood of animals as blood sugar. Dietary glucose can be directly absorbed and becomes then is often referred to as  “blood sugar”.

            Dextrose,  also labelled D-glucose, is another name for glucose – they are the same molecule. D-glucose with water (H₂O) becomes Dextrose monohydrate and is one of the two sugars that make up high-fructose corn syrup (HFCS )  [the other is fructose].

Fructose:   Chemical Formula – C₆H₁₂O₆

Fructose is often referred to as “fruit sugar” and is the sugar found in fruits and plants. It has the same chemical formula as glucose, but has a slightly different structure.  The liver converts substantial portion of fructose into glucose for distribution in the bloodstream. 

Lactose:  Chemical Formula – C₁₂H₂₂O₁₁                     

Lactose is a disaccharide composed of galactose and glucose.  It has the same chemical formula as sucrose but has a slightly different structure.  When found in mammal milks, it is commonly known as “milk sugar”. 

Galactose:  Chemical Formula – C₆H₁₂O₆

            Galactose  is  one of the sugars that make up the  disaccharide  lactose.  It has the same chemical formula as fructose.  It is sometimes itself  referred to as “milk sugar”. 

Maltose:   Chemical Formula – C₁₂H₂₂O₁₁

Maltose, or malt sugar, is a disaccharide formed from two units of glucose. It has the same chemical formula as lactose.   It is found in sprouting seeds that have their sprouting  stopped and then dried, known as malt.  Malted barley is used to make beers and whiskeys, while other malted grains as used to make malted milk, malt vinegar and malt-flavored confections. 

[Click to view larger image]

All of these sugars are metabolized and utilized by the body as sources of primary energy: mostly through the conversion to glucose.   Dietary glucose needs no processing by the body and can be directly absorbed and enter the bloodstream as “blood sugar”, your body’s source of energy. Other sugars require some breakdown, or conversion, primarily into simple glucose. 

[Note:  This biological chemistry is far more complicated than this simple explanation but it suffices for this essay.]

“Dietary sugars are absorbed in the hepatic portal circulation [in the liver] as glucose, fructose, or galactose. The gut and liver are required to process fructose and galactose into glucose, lactate, and fatty acids.”

“Fatty Acids” sound bad to our ears;  we have a bad image of both acids and fat.  But, “Fatty acids (mainly in the form of triglycerides) are … the foremost storage form of fuel in most animals.”  [ source ]   Likewise, lactate, once considered “a waste by-product of anaerobic glycolysis [utilization of glucose in the muscles] with multiple deleterious effects”, is now better understood to be not only “a readily accessible fuel that is shuttled throughout the body but also a metabolic buffer ….it  also acts as a multifunctional signaling molecule through receptors expressed in various cells and tissues.” [ source ]

Why this focus on sugars?

The War on Sugar  is the nutrition science narrative which says “sugar is bad because we eat too much of it” —  is then used to vilify food producers who use sugar in their products – positioned as unnecessary, too much, wrong kind – an endless attack on a substance that is not only innocent, but is a necessary part of the human metabolism and the main source of quick energy for most higher life forms on earth.

The War on Sugar has morphed into the War on Food (UPFs) (and here and here).   Why do I think that the War of Food (specifically the hobby-horse of nutrition science vilifying so-called Ultra-processed Foods – UPFs) is a continuation, an extension, of the War on Sugar?

All of the anti-UPF studies have a commonality that looks like this:

All of the other categories are either slightly beneficial or “nothing done/no effect” as the hazard ratio uncertainty bars include one.  I discuss this in detail in What Junk Nutrition Science Looks Like.  In every research paper on so-called UPFs, the findings mirror the above chart of hazard ratios – the deleterious effects claimed for UPFs all derive from the over consumption of sugars of all types, usually represented by sugar-sweetened beverages and sweetened snack foods, which is associated with, but does not necessarily cause,  over-weight and obesity and thus diabetes,  and some effects from processed red meats ( see The Meat War).  None of the other sub-categories of UPFs show any clinically significant negative effects at all.   

The War on Food has been more than adequately covered here as linked above, but let’s drill down a little to see one major battlefield of those combined scientific wars :   High Fructose Corn Syrup (HFCS).

High Fructose Corn Syrup (HFCS)

There are important things to know about High-Fructose Corn Syrup.

I’ll start by quoting the current information from the U.S. Food and Drug Administration (US FDA) “High Fructose Corn Syrup Questions and Answers”:

Corn Syrup is just glucose:  “HFCS is derived from corn starch. Starch itself is a chain of glucose (a simple sugar) molecules joined together.  When corn starch is broken down into individual glucose molecules, the end product is corn syrup, which is essentially 100% glucose.  ….   To make HFCS, enzymes are added to corn syrup in order to convert some of the glucose to another simple sugar called fructose, also called “fruit sugar” because it occurs naturally in fruits and berries.”

High-Fructose Corn Syrup is just fructose and glucose, approximately 50/50:  “The most common forms of HFCS contain either 42 percent or 55 percent fructose….The rest of the HFCS is glucose and water. HFCS 42 is mainly used in processed foods, cereals, baked goods, and some beverages. HFCS 55 is used primarily in soft drinks. …. The proportion of fructose to glucose in both HFCS 42 and HFCS 55 is similar to that of sucrose.”

[Note:  The ratio of fructose/glucose in HFCS is 42/53 or 55/42, both approximately 50/50. Other sugars make up the remaining 5 and 3 %s. Water is not included in the percentages. ]

How is HFCS different from our common table sugar, sucrose?:  “Sucrose (sugar), the most well-known sweetener, is made by crystallizing sugar cane or beet juice. Sucrose is also made up of the same two simple sugars, glucose and fructose, joined together to form a single molecule containing one glucose molecule and one fructose molecule, an exact one-to-one ratio. …. In sucrose, a chemical bond joins the glucose and fructose. Once one eats, stomach acid and gut enzymes rapidly break down this chemical bond. …  In HFCS, no chemical bond joins the glucose and fructose.”

Compared to table sugar, High-fructose Corn Syrup is either slightly lower in fructose than table sugar as HFCS 42 or slightly higher as HFCS 55. The FDA uses this language “The proportion of fructose to glucose in both HFCS 42 and HFCS 55 is similar to that of sucrose.”

As a note, for pure apple juice the ratio is generally about 66/34 fructose/glucose – much higher in fructose than either of the two standard HFCS formulations.    

HFCS Bottom Line:

HFCS is just sugar water, with approximately the same ratio of fructose and glucose as table sugar (sucrose).  “High-fructose corn syrup (HFCS) is a fructose-glucose liquid sweetener alternative to sucrose (common table sugar).” [ source ] Some HFCS is lower in fructose and some HFCS is higher in fructose when compared with table sugar.  HFCS is a liquid, as the sugars are mixed with water.

With the basics covered here in Part 1, Part 2 will focus on the question:

If HFCS is just sugar water, with a similar composition to table sugar, why is it vilified?

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Author’s Comment:

As with other Science Wars, this topic is just too complex and complicated to cover in under 1500 words, thus I have spilt it into two parts: this introduction which will be followed shortly by a dissection of the “science” that has been used to turn HFCS into a villain.

I have long held that human nutrition, as a subject, is one field of science that suffers the most from fads, based on poor science, which become self-perpetuating and self-reinforcing:  unproven hypothesis becoming ‘facts’ by simple repetition. 

Please limit your comments to the materials presented in this, Part 1, of this essay.  HFCS is at the center of a swirling controversy with opinions varying wildly.   In Part 2, I will cover the studies that have been produced about HFCS.

Thanks for reading.

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