High fructose corn syrup (HFCS) became the blame for obesity in 2004 for when Bray, Nielsen, and Popkin published an article linking HFCS, predominantly from soda, to the increase in obesity. They claimed that over the years that HFCS elevated in consumption so did the rate of obesity, and that glucose and fructose are broken down differently in the body (1). They are not wrong about the two associations, but they are a correlation to obesity and not a direct cause.
The increase in soda would have most likely been the same, if it were sweetened with HFCS or sucrose (2). The breakdown of sucrose and HFCS is not very different. Sucrose is made up of 50/50 glucose and fructose. There are two types of HFCS that are commonly used in food today, HFCS-42 and HFCS-55. HFCS-42 is made up of 42% fructose and HFCS-55 is made up of 55% fructose (3). The rest of the sweetener is mostly glucose and a small amount of other carbohydrates (3). When eaten in the diet, HFCS is made up of free glucose and free fructose (1). Glucose and fructose in table sugar is absorbed similarly. There is a covalent bond between the two sugars, which is broken down by an enzyme in the intestines, making the free fructose and glucose for absorption (1).
The increase in the obesity epidemic is not caused by HFCS, or other sweeteners, but rather from an increase in total calories (3).
1. Klurfeld DM, Foreyt J, Angelopoulo TJ, Rippe JM. Lack of evidence for high fructose corn syrup as the cause of the obesity epidemic. Int J Obes (Lond). 2013;37(6):771-3
2. Jacobson MF. High-fructose corn syrup and the obesity epidemic. Am J Clin Nutr. 2004;80(4):1081.
3. White JS. Straight talk about high-fructose corn syrup: what it is and what it ain’t. Am J Clin Nutr. 2008;88(6):1716S-1721S.
