Dangers of an Ultra Low Fat Diet

author avatar Dr. Eric Berg 08/31/2023

People are scared that fat is linked to heart disease, high cholesterol, obesity, and other health problems. So it isn't uncommon for people to fall for the fat-free or low-fat diet fads. But when we get rid of fat in our diets, we end up with all sorts of problems. Limiting fats in an extreme way can lead to more harm than good. In this article, I'll share with you the top low-fat diet dangers that you'll want to be aware of.

I will cover:


What is an ultra-low-fat diet?

Low fat text red stamp on white background, low-fat diet, low-fat foods concept.

People who follow an ultra-low-fat diet consume very small amounts of fat. On this low-fat diet, fats make up only 15% of the total calories you eat.

But is that really a healthy option?

The answer is no. Here is the bottom line: you don't want to limit your fat intake. The diet I recommend for improving your health, promoting weight loss, and supporting health conditions has fat making up about 70% of your total calories. That is much more than an ultra-low-fat diet.

I believe that there are a lot of things in fat that we need. And that we can really improve our health by eating plenty of good quality fats.


Why do we need fat?

Fresh avocado halves arranged in circle on table with nuts and seeds, healthy fats, good fats.

Fat has been made out to be the enemy to health. But that is just a myth. In truth, fat intake is vital for staying healthy. It is an essential part of the human diet.

There are a lot of reasons our bodies need fat to survive. Fat plays a key role in many different body structures and functions. For example, fat helps us to:

  • Get fat-soluble vitamins like vitamins A, D, E, and K
  • Get essential fatty acids that our body can't make – we have to get them through our diets.
  • Build structures like our cell membranes.
  • Make hormones.
  • And much more.

We really need fat in our diets. When we limit our fat intake, as with low-fat diets, it can become very unhealthy and it can cause much more harm than good.


7 Low-fat diet dangers

Without enough fat in our diet, things can start to go wrong in the body. Here are some of the risks of eating too little fat.

1. Deficiencies in vitamin A, D, E, and K.

- Vitamin word cloud with vitamin E capsule in front. Words like medicine, lifestyle, health, wellness.

Fat soluble vitamins like A, D, E, and K are absorbed with fat. These nutrients are very important to your overall health. Deficiencies in these nutrients can lead to various problems. For example:

  • Vitamin A deficiency can impact your vision and your immune system.
  • Vitamin D deficiency can lead to compromised immune function, higher levels of inflammation, and low calcium absorption.
  • Vitamin E deficiency can be detrimental for your heart and hormone health.
  • Vitamin K deficiency can lead to calcium and clotting issues.

2. Risk of mental health problems.

Your brain is mostly made up of fat. And your nerves are insulated with it. If you don't have enough fat, you won't have the structural components for your brain and nerves to stay healthy. And as a result, your cognitive function can suffer. This means you could end up with mood or mental health issues.

3. Increased risk of cancer.

The essential fatty acids that you must get through dietary fat sources help keep your immune system healthy. If your immune system isn't functioning at top speed, you may have a higher risk of getting diseases like cancer.

4. Decrease in HDL and increase in triglycerides.

When you don't consume enough healthy fats, you can end up with low HDL cholesterol and high triglycerides. To protect against heart disease and stay healthy, you want the opposite.

5. Too many carbs.

When you take fats out of your diet to such an extreme level, those calories have to be replaced by something. And most people who try ultra-low-fat diets end up increasing their carbohydrate intake as a result.

Low amounts of fat and high amounts of carbs is not a good combination. It will not support weight loss or better health. In fact, it can make things a lot worse and put a lot of strain on your body.

Low fat text red stamp on white background, low-fat diet, low-fat foods concept.

6. Always feeling hungry.

Without fats in your diet, you'll end up never feeling satisfied and you will always feel hungry. Low-fat foods aren't satisfying and won't keep you full for long. That is not a good thing if you are trying to lose weight and stick to a diet.

7. Damage to your liver and kidneys.

Along with increasing your carb intake, you are also likely to eat lots and lots of protein if you go low fat. But low fat and high protein is really hard on the liver and the kidneys. This combination will also increase Fat Storing Hormone levels and can lead to things like Fat Storing Hormone resistance over time.

You always want to consume the natural fat that comes along with protein. You want to stay away from lean protein and low-fat meat.


More fat, less weight?

A lot of people are afraid that if they eat fat, they'll gain weight, get high cholesterol, and become unhealthy. But the opposite is actually true. Fat is a key component to losing weight. Carbs are the real culprit behind weight gain, which is why I recommend the Healthy KetoTM diet full of nutritious foods, a good amount of fat, and very little carbs.

To learn more about why fat can actually help with weight loss and health, check out these resources:

- A collection of healthy dietary fats like salmon, poultry, avocados, nuts, and eggs in bowls on table.



There are a lot of myths out there when it comes to health. For example, many people think that eating dietary fats will make you fat, or that saturated fats will give you heart disease. But this just isn't true.

When it comes to things like weight gain, obesity, heart health, and more, eating healthy fats isn't the problem. In fact, going super low fat can be quite dangerous for your body. Here are some of the risks of limiting your fat intake:

  1. Vitamin deficiencies.
  2. Mental health concerns.
  3. Increased cancer risk.
  4. Low HDL and high triglycerides.
  5. High carb intake.
  6. Increased hunger.
  7. Liver and kidney problems.

Don't make the mistake of limiting your fat intake with an ultra-low-fat diet. It won't do your body any good, and it can come with some real dangers and risks. Instead, make sure to fill your diet with plenty of good, healthy fats.

Not sure what kind of fats to eat? Learn more in these resources:

I recommend the Healthy KetoTM diet, which is made up of high fat, a moderate amount of protein, very little carbs, and lots of healthy nutrients.

What are your thoughts on ultra-low-fat diets? Share your questions and comments below.

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Disclaimer: Our educational content is not meant or intended for medical advice or treatment.

Editor’s Note: This post has been updated for quality and relevancy.

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