How can a high fat diet, like the popular keto diet, lead to digestive problems?

Fat in your diet has been unfairly blamed for many health conditions, when in fact you can only obtain fat-soluble vitamins from fatty foods. Indeed, the dried weight of your brain is around 60% fat, so how can fat be that bad?

Like most things in life, it depends what you mean by fat. Fats come in many different guises, such as fats from animal products, which tend to be hard and fat from plants, such as olive oil, that are liquids.  You can also obtain fats from nuts and seeds and you can only obtain a certain kind of fat, vital for health, from oily fish.

Good fats vs bad fats

However, many people eat a lot of unhealthy fats, found in highly processed foods, such as biscuits, crisps and ready meals or low-quality fats used in restaurant cooking. These come mostly from refined processed oils from seeds, soybean and corn and are all damaged through high heat exposure during cooking, especially, if eaten day after day, year after year. These damaged fats are then incorporated into your cell membrane, which contributes to a multitude of health problems, including digestive problems.

Furthermore, too much fatty foods tend to slow down the digestive process, making you more prone to constipation. Coupled with the fact, that they are often found in low-fibre, high sugar foods, this is a recipe for digestive problems.

Is the keto diet good for the long-term?

But I am on a keto diet? While this might not be a bad option in the short term for a number of reasons, such as weight loss, the jury is out in the scientific community with regards to the long-term impact a ketogenic diet has on your gut microbiome. As your gut bacteria can only thrive on plant-based foods, I would not recommend a keto diet as a long-term solution for most conditions, although, as ever, there are exceptions to this rule.

Since it's important to get some fat in your diet, pairing healthy fatty foods with high-fibre foods can make them easier on your digestive system. 

  • Choose lean meats. Protein is an essential part of a healthful diet, but fatty cuts of meat can lead to uncomfortable digestion. When you eat meat, select lean cuts, such as pork loin and skinless poultry.
  • Limit the intake of fatty foods.
  • Eat them in moderation and try to pair them with other healthy foods, such as plenty of vegetables.

Choose healthy fats. Healthy fats help improve your digestive health. In fact, research shows people with irritable bowel syndrome may not be getting enough omega-3 fatty acids from fish.

The key is limiting your fat intake. Your diet should be low, but not absent, in saturated fat, the fat that raises your blood cholesterol and slows digestion. Unsaturated fats in the right proportion tend to be better for your body. They’re the ones you get from fish and olive oil. They’re also good for your heart.  As ever, it is the mix of fats that are important. If you are obtaining most of your fats from animal products, then by definition, you are possibly not obtaining enough from fish and plant-based sources.

Summary: Chose your fats carefully, by making sure you eat plenty of oily fish, using good quality olive, eating nuts and seeds and avoiding highly processed foods, that contain poor quality and health-damaging fats.

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

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London SW15 & W1H
Written by Melody Mackeown, mBANT, CNHC, BSEM | Nutritional Therapist and Health Coach
London SW15 & W1H

Melody has a Masters Degree in Personalised Nutrition and specialises in helping you with problems conceiving, gut problems, autoimmune disorders, weight loss and more.

Melody treats the whole person, not just the disconnected symptoms and as a result, clients typically see significant positive improvements to their health within just 3-6 months.

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