Sugar has been blasted in recent years for its link to obesity and a slew of health problems, but now experts say the food world has a new problem child: Soybean oil.
Soybean oil, considered a “healthier” alternative to some oils that contain more saturated fat, actually leads to more weight gain than fructose, according to new research on mice that was published in the journal PLOS One.
For their research, scientists divided the mice into four groups and fed them each a different diet that contained 40 percent fat (similar to the average American diet). One diet used coconut oil (which largely consists of saturated fat), another used half coconut oil and half soybean oil (which primarily contains polyunsaturated, or “good” fat). The third and fourth diets had fructose added.
All four diets had the same number of calories, and the mice were fed the same amount of food.
Here’s what researchers discovered: Mice that were on the soybean oil diet gained 12 percent more weight than those that ate a fructose diet, and 25 percent more weight than mice on the coconut oil diet.
The mice on the soybean oil diet also had larger fat deposits in their bodies and fatty livers, and were more likely to have developed diabetes and insulin resistance. Mice on the fructose diet didn’t get off easy, either — they had similar issues, but to a less severe degree.
And, it’s worth noting, the amount of soybean oil the mice ate was similar to what we get in our diets.
Oils from plants — including soybean oil — have gained popularity after research linked the saturated fats in butter to an increased risk of heart disease. While the American Heart Association specifically recommends using olive, canola, corn, and safflower oils for heart health, soybean oil is also popularly used.