Is High Fructose Corn Syrup The Reason Why You Aren’t Losing Weight?

by Sarah Limbert, RDN, LD

Last Updated: October 27, 2020

You are likely familiar with high fructose corn syrup. Perhaps you’ve heard about this ingredient on the news, or you’ve seen it listed on the back of your soda can. We have heard it from all sides: some say it’s harmless, while others say it’s the cause of the obesity epidemic. With all the conflicting information out there, we decided to take a deep dive into the research to find everything you need to know about high fructose corn syrup.

What is high fructose corn syrup? High fructose corn syrup (HFCS) is a man-made product produced by food manufacturers from milled corn. It is added to foods to increase the overall taste and sweetness of products. HFCS is the sweetener of choice by many manufacturers because it is low in cost and sweeter than table sugar. Sucrose is another name for table sugar and is composed of two simple sugars: 50% glucose and 50% fructose. HFCS is also made from glucose and fructose, but in a different ratio: 45% glucose and 55% fructose. The higher amount of fructose in HFCS is the reason behind the extra sweetness it provides to foods. The most common HFCS source in the American diet is soda, but it is also found in salad dressings, condiments, granola bars and many common foods.

Why does this matter? The concern regarding HFCS is the higher percentage of fructose compared to glucose. When digested by the body, fructose is absorbed and metabolized through a similar pathway as glucose, except that fructose skips a few steps. These steps are key points of regulation in which the body decides whether or not to move forward with metabolism. This means that when excess fructose is consumed, like from high fructose corn syrup, there is the potential for increased absorption and metabolism of fructose. When these two steps go unregulated, we run the risk of storing these excess sugars as fat.

It’s important to note that fructose is naturally found in various foods including fruit, vegetables, and honey. But we all know fruits and vegetables are healthy for us, right? So, what’s the deal? Fruits and vegetables are also packed with vitamins, minerals, fiber, and water. In combination with fructose, these nutrients create a higher nutrient density and create a favorable change in digestion. With HFCS, the body quickly absorbs this simple sugar, causing our blood sugar to spike and quickly drop. This can lead to insulin resistance issues, hunger disruption and can alter satiety (feeling of fullness) cues. When fiber is involved, the fructose is not absorbed as quickly allowing for a favorable and gradual digestion process. It’s important to think about the source of the fructose: fruits and veggies packed with nutrients versus fructose in soda, in the form of HFCS, a simple sugar with limited to no nutrients.

Is High Fructose Corn Syrup Why You Aren’t Losing Weight? Unfortunately, this question doesn’t have a simple yes or no answer. We do know that HFCS alone is not the cause of obesity or weight gain. Let’s start by looking at the big picture. A lack of weight loss can often be contributed to, in broad terms, including excess calorie intake and limited physical activity. The intake of HFCS could be a contributing factor to excess caloric intake. Instead of focusing on one ingredient, we need to look at overall foods eaten to find the correct balance of calorie intake, nutritional value of your food, physical activity and individualized needs. When we think of the most common source of HFCS (soda), we can all agree it is not the most nutritious choice. However, a small amount of HFCS in your salad dressing may significantly boost the flavor of your nutrient-rich salad while only adding small amounts of HFCS (if portioned correctly). Instead of focusing on one ingredient, let’s make sure to look at the bigger picture of our food choices to make the most nutritious choice.

What to do now? Now that we understand high fructose corn syrup and its relation to weight gain let’s talk about daily intake of added sugar. High fructose corn syrup is considered a form of added sugar. In general, we want to limit our added sugar intake to 25 grams or less per day for women and children and 36 grams or less per day for men. Follow these guidelines and you won’t have to worry about whether your added sugar intake comes from high fructose corn syrup or regular table sugar. Looking for more information? Sign up for a one-on-one appointment with a Kroger RD.

Disclaimer: This information is educational only and not providing healthcare recommendations. Please see a healthcare provider.


Sarah Limbert, RDN, LD

Sarah Limbert, RDN, LD

Sarah has experience working with patients on everything from weight loss to fertility, to seizure management. She’s a true expert on how patients can benefit from ‘food as medicine,’ all while maintaining their lifestyle and livelihood. In her spare time, she leads a non-profit focused on providing basic needs and creating a future for children in India, Kenya and locally in Cincinnati.