Fructose and Weight Gain: A Bad Rap?

Experts examine whether the sweetener known as fructose contributes to the obesity epidemic.

Medically Reviewed by Louise Chang, MD
3 min read

In an attempt to explain the ever-increasing (no pun intended) incidence of obesity in the U.S., fingers have been pointing of late to fructose. It's a sweetener found naturally in fruit and honey and as a component of high-fructose corn syrup, which is used in sweetened foods and beverages.

Some research has suggested that fructose may stimulate a hormonal response in the body that promotes weight gain. Other studies have hypothesized that fructose, vs. other forms of sugar, may trick you into thinking you are hungrier than you should be. But is fructose the real culprit? Many experts don't think so.

"I believe recent allegations suggesting that fructose is uniquely responsible for the current obesity crisis in the U.S. are unfounded," says biochemist John S. White, PhD, a researcher and consultant who specializes in nutritive sweeteners. "These allegations -- such as increased fat production or increased appetite -- are based on poorly conceived experimentation of little relevance to the human diet, which tests unphysiologically high levels of fructose as the sole carbohydrate, often in animals that are poor models for human metabolism."

Even the FDA, says White, has concluded that "high-fructose corn syrup is as safe for use in food as sucrose, corn sugar, corn syrup, and invert sugar."

There are many foods that contain fructose, says Shirley Schmidt, CDE, a diabetes nutrition educator at William Beaumont Hospital in Royal Oak, Mich. Fructose is a natural sugar found in many fruits and vegetables. Table sugar, or sucrose, is half fructose and half glucose. And as a component of high-fructose corn syrup, fructose is found in everything from soda to fruit drinks, sports beverages, chocolate milk, breakfast cereals, flavored and dessert syrups and toppings, baked goods, candy, jam, sweetened yogurt, and many other packaged convenience foods.

And while it may be true that you'll gain weight by eating too much of the above fructose-filled foods, you'll gain weight if you eat too much of any food, says Schmidt.

"I don't believe that limiting any single food ingredient would be at all effective," agrees White. "Obesity is caused by a host of environmental, psychological, and physiological factors. All macronutrient food ingredients -- fats, carbohydrates, and proteins -- will contribute to weight gain when consumed to excess. … That may not be a trendy position, but it is one that is consistent with rational science."

"There's no reason to avoid fructose itself," says Madelyn Fernstrom, PhD, CNS, director of the Weight Management Center at the University of Pittsburgh Medical Center. If you're looking to lose weight -- or at least not gain any -- Fernstrom recommends that you limit your consumption of fructose-sweetened beverages and snack foods just as you would any simple carb. Of course, cutting back your total calorie intake wouldn't hurt either.

Keep your total carbohydrate intake to no more than 50% of your daily diet, Fernstrom advises, and make sure that most of those carbs come from fiber-rich sources such as whole grains and vegetables rather than added sugars or processed foods.

"There are hidden calories in beverages and foods such as sodas, cookies, and cakes, but that's not solely because of fructose," says Fernstrom.

Added sugars in general -- no matter in what form -- can be a significant factor in obesity, says bariatric surgeon Michael Trahan, assistant professor of surgery at the University of Texas Medical Branch.

Reading food labels is a good way to limit your intake of fructose and other sugars, adds Trahan. Avoid any packaged food product that lists as one of its first three ingredients anything ending in "ose" -- the chemical suffix that indicates "sugar."

To satisfy your sweet tooth, choose fruit instead -- "nature's candy," says Fernstrom. "Few people are overconsuming natural fructose by eating fruit."