Questions & Answers

High Fat Diets And Your Gut: What You Need To Know

Is a high-fat diet bad for your gut?

That’s an interesting question, and I think this question came in response to a published study from China.

The research put 200 people onto a variety of diets. There was a relatively low-fat diet, with about 20% of the calories from fat. There was an intermediate fat diet with about 30% of calories from fat. Lastly, there was a high-fat diet, with about 40% of calories from fat. The protein and fiber content were the same for each diet. It was just the percentage of fat calories that increased.

What they found was very interesting. After some time, stool and blood samples were taken from all study participants.

The results should that for mainly people ages 18-35, the bowel flora differed based on diet. Subjects eating more fat had higher levels of Bacteroides, a bacteria associated with fat and meat consumption. Thes same subjects had lower levels of Bifidobacteria and Blautia. Long-chain fatty acids (LCFA) were higher in the bowels of people eating higher fat diets. LCFA are byproducts of fermentation in the bowel. Short-chain fatty acids (SCFA) are good for the bowel, but LCFAs can be problematic.

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LCFA can lead to more inflammation and conditions like diabetes, heart disease, and cancer.
In this study, the predominant source of fat was soybean oil. Keep in mind that soybean oil isn’t a great oil to include in your diet.

In other words, this study did not use healthy fats from salmon, avocado, nuts, or seeds. (Although, keep in mind that not all seed oils are good).

Because the fat provided in this study wasn’t monounsaturated from what I can gather, and the possibility of deep-fried foods being ingested, these factors may explain some of the findings.
In other words, don’t automatically assume that a high-fat diet is going to create a big problem. It depends on how much fat you’re eating in relation to protein, carbs, and fiber. It also depends on the type of fat you are eating. And, of course, lifestyle factors like alcohol intake, stress, and physical activity will influence your gut flora.

I wouldn’t assume that a high-fat diet is bad for you based on this study. But, if you’re eating the wrong kinds of fat, you could run into problems. Deep-fried chicken nuggets and French fries aren’t going to help your gut any.

Monounsaturated fats like olive oil and foods that contain omega-3 fatty acids (e.g., salmon) are going to be way better for your gut than these saturated fats.
What I take from this study is that take-away food made with low-quality fats is bad for your gut.

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