Think Twice Before You Start a Low Fat Diet

author avatar Dr. Eric Berg 08/31/2023

How often over the years have you heard you should be eating a low-fat diet?

Too many to count, I bet.

But did you know that when you don’t eat enough fat, your health suffers in various ways? Not only that, but eating low fat doesn’t necessarily help you lose weight!

In this article, I’ll explain:

I did extensive research on the scientific research about low-fat diets. What I discovered is significant data showing the risks and potential downfalls of eating too little fat. Even though for decades you’ve been told to follow a low-fat diet to reduce your cholesterol, thus sparing yourself the alleged artery-clogging and life-threatening cardiovascular disease sure to end your life prematurely, the actual results of eating low fat are sobering.

Eating too little fat not only doesn’t help to reduce cholesterol - or lose weight, for that matter - it has other hazardous effects on your health.

Here’s what I found.


#1 Less Weight Loss

65 high-quality studies showed that the people on a low-fat diet had less weight loss than those not on a low-fat diet.

Frustrating, isn’t it? But a food’s fat content doesn’t determine if it’s actually healthy or not.

If you’ve been following me for awhile, you know that high-fat foods like avocados, eggs, olive oil, and cheese can be part of a healthy diet. And those processed foods like low-fat diet ice cream and fat-free gummy worms aren’t exactly health food stars.

a photo of a variety of colored gummy worms

Unfortunately, when they go on a low-fat diet, many people eliminate those high-fat healthy foods in favor of low-fat processed foods. They ditch wholesome foods like fruits, vegetables, and meat. Many of these foods, even if they contain less fat, often contain more sugar than their full-fat counterparts - otherwise, with the fat stripped out, they’d be so tasteless none of us would eat them. And all that added sugar wrecks your weight loss efforts.

So, if you’ve been beating up on yourself for not losing the weight you’d like while faithfully following a low-fat diet, you now know it’s not your fault.

#2 Increased Cholesterol

As well, their blood lipids (fat) levels increased - even though they weren’t eating much fat. Isn’t that interesting? From all the information you’ve been told for several decades, you’re supposed to believe that eating less fat will result in lower cholesterol, not higher.

a drawing of cholesterol particles in the blood

But here’s why your cholesterol can rise when you eat too little fat.

Your body makes over 75 percent of the cholesterol that’s found in your body. Thus, if you eat less fat, your body will make more in response, in order to try to maintain sufficient cholesterol levels for your health.

#3 Lowered Metabolic Rate

Your body needs a certain number of calories each day simply to sustain normal functioning.. When you consume too little fat, your body responds by lowering your metabolic rate, resulting in it needing fewer calories to accomplish its basic functions. In other words, even when you significantly lower your fat intake to lower your calorie intake, your body will adjust by requiring fewer calories.

Then, you end up being unable to lose weight.


#4 Lowered Satiety And Overeating

When you aren’t satisfied by your food, you get hungry. You know this, right?

a young man stuffing his face with food

Fat is satiating; when you eat healthy fat, you feel full between meals and aren’t tempted to snack.

On a low-fat diet, the opposite is true. You get miserably hungry.

Your cravings overwhelm you. Eventually, you give in and overeat.

#5 Hormone Deficiency

Studies show that low-fat diets cause crucial hormones to decline, epecially the sex hormones estrogen and testosterone.

This happens because fat is the raw material of all of your sex hormones. When you cut out sufficient levels of fat, you starve your sex hormones.

a photo of a hormone level meter

The results can be devastating:

  • Increased risk of heart disease, osteoporosis, and obesity
  • Depression
  • Diabetes

#6 Worsened Fat Storing Hormone Resistance

In one study, the group on a low-fat diet experienced worsened Fat Storing Hormone resistance, a pre-diabetic condition in which both your blood sugar and Fat Storing Hormone levels are chronically high. Left untreated, Fat Storing Hormone resistance can result in full-blown type 2 diabetes.

If that’s not bad enough, Fat Storing Hormone resistance often results in higher cholesterol.

This happens because when you have Fat Storing Hormone resistance, there are high levels of Fat Storing Hormone in your body. Fat Storing Hormone is a precursor to cholesterol; meaning that Fat Storing Hormone readily converts to cholesterol in your body. More Fat Storing Hormone can result in higher levels of cholesterol.

In another study, the low-fat group showed a higher rate of metabolic syndrome, another pre-diabetic condition. Metabolic syndrome is actually a cluster of conditions that occur together. These conditions include increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels.

If you compare a low-carbohydrate diet such as Healthy KetoTM, the low-carb diet showed much better results with improving Fat Storing Hormone resistance when compared to the low-fat diet.

#7 Increased Risk Of Death

Tens of thousands of people who were in a dietary study showed a higher mortality rate for those on a low-fat diet.

Startling, isn’t it? All those years when a low-fat diet was recommended as healthy, yet it actually can shorten your lifespan.

#8 Impacts On The Brain

In one study, people eating a low-fat diet experienced some cognitive impairment. They became more angry and hostile.

Sounds strange, doesn’t it? I bet you didn’t realize that consuming too little fat can cause anger and hostility.

But your brain, nervous system, and hormones need enough fat to correctly function. Without it, you can be left struggling with everyday activities, resulting in frustration and anger as you decline.

As well, a low-fat diet significantly increases your risk for depression. Although studies have shown the increase, the link isn’t clear. It may be because you produce less of the feel-good neurochemical called serotonin, the neurotransmitter most associated with depression.


Low-Fat Diets Are A Problem

Over the last several decades, we’ve essentially been subjected to a giant experiment of being strongly encouraged to eat a low-fat diet.

As you can see, this experiment failed miserably.

Eating too little fat isn’t sustainable.

It didn’t result in people losing more weight.

Too little fat derails normal functioning of the hormones your body needs to be healthy. You can end up obese, depressed, and at high risk for diabetes.

But the good news is that what I’ve told you in this article also explains why the opposite diet, the high-fat, low-carb, moderate protein keto diet, is truly effective. People stick to it because it benefits not only their weight loss, but also their hormones, their Fat Storing Hormone resistance, and their cognitive function.

In other words, keto works.

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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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