In recent years, high-fructose corn syrup (HFCS) has been projected as one of the leading causes of the obesity epidemic in Americans. But, does science really support this view? With all the public shaming and campaigns against HFCS, we wanted to take a closer look at how HFCS stacks up against other types of highly-refined sugar before casting it as the dietary villain.
Sugar is naturally found in many types of food, such as fructose in fruits and lactose in milk. Added sugar, on the other hand, comes from a variety of sources and are added to your food to improve taste. These may include natural sugar sources such as honey from bees, agave nectar and maple syrup. Others must be highly refined such as sugar cane and sugar beets to make white and brown sugar, stevia and corn syrup.
All sugars are a type of carbohydrate, which are broken down into glucose (blood sugar) to be used by your body as fuel. Simple carbohydrates are broken down relatively quickly and can create a spike in glucose levels, whereas complex carbohydrates take longer to be digested and absorbed. The American Heart Association recommends limiting the amount of added sugar to only about 25-37 grams, roughly 100-150 calories per day. Unfortunately, most Americans far exceed this recommendation.
High fructose corn syrup is a liquid sweetener that is used in many foods and beverages, and is often used as an alternative to table sugar (sucrose). Because HFCS is a liquid, it does not need to be dissolved in water like sucrose does. The use of HFCS in foods and beverages began in the late 1960s, and its use has increased exponentially since primarily because it is easier and cheaper to produce and use. Sucrose is derived from sugar cane and sugar beets that are grown primarily in equatorial regions, so its price and availability can fluctuate significantly with political and climate instability. Corn, on the other hand, is more readily and abundantly available and affordable in the U.S.
Foods and beverages with high levels of added sugar of any kind offer very little in the way of nutrient or fiber value. This includes non-diet soda, sweet tea, energy drinks, sports drinks, cake, candy, pastry, syrup, fruit-flavored drinks, etc. Keep in mind that empty calories are not just found in products with lots of added sugars, but in products with high levels of saturated fat and alcohol as well. Sauces, soups, and many everyday food products also may contain added sugar.
IS HFCS DIFFERENT FROM OTHER SUGARS?
There is a lot of confusion about the composition of HFCS, which is different than generic corn syrup and table sugar. As shown in Table 1, corn syrup is 100% glucose. Sucrose and HFCS are both composed of glucose and fructose with only a 5% difference in the levels of each, making the term “high-fructose” a bit misleading.
Despite these minor differences, all dietary sugars have four calories per gram, regardless of the source. And because the fructose/glucose levels between HFCS and table sugar are so similar, the body doesn’t register any significant difference between the two.
Table 1. Carbohydrate composition of four common sweeteners.
SUGAR IS SUGAR
In 2010, an article in the American Journal of Clinical Nutrition proposed that HFCS is a direct cause of obesity. The article looked at the corresponding increase between HFCS consumption and rising obesity rates. While the connection was convincing at first, the research failed to prove that HFCS is the cause of obesity. HFCS consumption is associated with obesity, but it is not a cause and effect relationship.
The more important question is whether or not obesity is caused by the overconsumption of more calories from sugar per day than ever before (combined with an overall lack of adequate physical activity to expend those calories). Between 1971 and 2010, the average American increased their daily caloric intake from 2150 to 2700 - a 25% increase in daily calories consumed. It’s safe to say that we did not increase our calorie expenditure through physical activity by the same amount to counter that increase. In fact, only about 20% of U.S. adults currently meet the minimum public health guidelines for physical activity.*
Despite the public’s perceptions, scientists have not found anything unique about HFCS that would cause it to be any more obesity-promoting than any other sweetener. Interestingly, while the obesity rate in the U.S. has increased from 16%, 20%, 25%, 31%, and 36% for 1995, 2000, 2005, 2010, and 2015 respectively, our overall intake of HFCS in the U.S. has remained steady since about 2000.
The conclusion is that high fructose corn syrup is not significantly different than any other added sugar. Most Americans should cut down on their intake of all added sugars to decrease intake of empty calories. The consumption of fruit is still encouraged because fruit is still rich in fiber and many other nutrients. While eight ounces of 100% fruit juice counts as a serving of fruit, you should be aware that given the choice, a piece of fruit is preferable to a cup of 100% fruit juice because of the fiber-containing property of the fruit and the higher sugar content of the juice. As a general rule of thumb for long-term weight control, we must stick to nutrient-rich foods and cut way back on empty calories while also substantially increasing our physical activity levels.
*The 2018 Physical Activity Guidelines for Americans suggests that adults get a minimum of 150 minutes per week of moderate aerobic physical activity, as well as at least two days per week of resistance training.
White, J. S. (2008). Straight talk about high-fructose corn syrup: what it is and what it ain’t. American Journal of Clinical Nutrition, 88(supplement):1716S-1721S.
Bray, G. A. (2004). Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. American Journal of Clinical Nutrition, 79:537-543.