by Dana M Robinson - Published 6 months ago

High-Fat Diets: Healthy or Harmful? New Study

Key takeaways:

The keto diet has become popular, but high fat diets may not be as good for you as they claim.

A recent study with mice* found that diets high in fat can lead to obesity, diabetes, and other health issues.

Particularly, soybean oil—compared to coconut oil and commonly found in processed foods—may have a negative impact on health.

Moderating fat intake and focusing on whole foods like fruits, vegetables, and lean protein is important for staying healthy.

While fat is necessary, it should be consumed in moderation from healthy sources like avocados, nuts, and seeds.

Unhealthy fat consumption can impact the immune system and brain function, and exercise alone may not offset its effects.

Keto this, keto that. Grocery store aisles are filled with “keto-friendly” alternatives to their carb-filled counterparts and every other Instagram health guru seems to be touting the benefits of going low carb. The keto diet has become one of the most popular out there, with some 23 million Americans following it in 2022, according to Harvard. But are high fat diets actually as good for you as they claim to be?

A recent study conducted by the University of California, Riverside revealed some surprising new truths about consuming a diet high in fat — and it’s not great news for the keto evangelists.

TL;DR: Even if you aren’t eating steak and eggs for every meal or blending butter into your morning coffee, you could be eating too much fat.

This could have significant implications for your health and well-being.

The study's findings

In a study, mice were fed diets with more than 40% fat, which is close to the typical standard American diet.

“The average American consumes around 40% of their daily calories from fat sources, while the recommended intake is 25-35%,” said Stephanie Tarnacki, RD. She added that most of this fat comes from processed foods and animal products, which are often high in saturated and trans fats.

For the study, mice were given either conventional soybean oil (polyunsaturated fat), modified soybean oil similar to olive oil (monounsaturated fat), or coconut oil (saturated fat).

After 24 weeks, the researchers analyzed intestinal tissue to study the gut microbiome and used RNA sequencing to identify any genetic changes. Their findings revealed that:

Soybean oil can lead to weight gain, diabetes, insulin resistance, and fatty liver disease.

Soybean oil also negatively affects gut health and genes associated with autism, Alzheimer's disease, depression, and other conditions.

This is not unexpected, as research has consistently shown that high-fat diets can increase the risk of cardiovascular disease and high blood pressure, as well as other health problems.

“This study suggests that a high-fat diet, regardless of whether it comes from animal or plant sources, may increase the risk of colon cancer, gut microbiome imbalance, weakened immunity, and a higher chance of obesity, Type 2 diabetes, and fatty liver disease,” Tarnacki explains.

Different types of fat have different effects

Although the study concluded that a high-fat diet, regardless of type or source, can have negative health effects, some sources of fat are more harmful than others. In this study, soybean oil was found to be more detrimental than coconut oil.

The USDA states that soybean oil is the most widely produced and consumed edible oil in the United States. It is used in a variety of products, including salad dressing and frozen foods.

According to a study published in Nature, soybean oil had the most detrimental effect on gut health and was significantly linked to increased risks of obesity, insulin resistance, and type 2 diabetes, Tarnacki warned.

Implications for our diet

While acknowledging that there is no one-size-fits-all diet, research emphasizes the importance of controlling fat intake for overall health.

Tarnacki suggests following a plant-based diet rich in fruits, vegetables, whole grains, and lean protein sources like fish, turkey, and chicken. It is also recommended to limit processed foods as they often contain high levels of saturated fat.

Although fat is essential for various reasons, such as vitamin and nutrient absorption, and hormone health, moderation is crucial. Tarnacki advises consuming healthy fats from whole food sources like avocados, nuts, seeds, and olives.

Ultimately, health begins with dietary choices. If you believe that extra exercise can compensate for excessive unhealthy fat intake, reconsider.

“Consistent consumption of such diets might affect your immune system and brain function,” stated Poonamjot Deol, UCR microbiologist and co-first author of the study. “Exercise alone may not fully mitigate these effects.”

*Mouse and animal studies may not reliably predict human responses to similar exposures.