Good Fats vs. Bad Fats for Keto

Dieser Artikel basiert auf wissenschaftlichen Studien

Bad fats vs. good fats on keto: ✅ saturated, ✅ monounsaturated fat, ✅ polyunsaturated fat, ✅ trans fats, ✅ what makes the difference.

The public demonization of fat induced countless health problems in the western world over the decades.

However, if you want to regain control of your health and put more healthy fat into your diet again, the difference between good and bad fats is essential.

For example, fats in a low-carb high-fat (LCHF) diet like keto provide at least 70% of the daily energy.

Therefore, this article aims at comparing good fats vs. bad fats on a keto diet. Hence, you will learn more about different types of fats and the foods that bring them into your diet.

Moreover, you will learn how the myth that fat is bad evolved. Therefore, I will use studies to explain how science has already debunked this myth countless times.

What Are Good Fats for Keto?

Good keto fats can be divided into four types of fat:

  • Saturated fats
  • Monounsaturated fatty acids (MUFA)
  • Polyunsaturated fatty acids (PUFA)
  • Natural trans fats

In nature, fats always occur as a combination of these different types of fat. Thus, it is impossible to say that all saturated fats are healthy or unhealthy.

Although bacon, for example, is known for saturated fatty acids, the lion’s share comes from the same monounsaturated fatty acid that we know from olive oil. Also, bacon contains PUFAs.

Nevertheless, fats are primarily categorized based on their predominant fatty acid. To differentiate between good fats vs. bad fats on keto, we must explain these different (chemical) types of fats.

Good Saturated Fats for Keto

Although we have been eating them for hundreds of thousands of years, saturated fats have been carrying the image of causing heart disease for more than a century.

Historically, there are countless reasons  for this, such as (selection):

  • The marketing of trans fats from hydrogenated vegetable oils as “healthy,” which already began shortly after the discovery of the chemical process in 1911,
  • The media-effective scientist Ancel Keys, who manipulated studies to substantiate his erroneous hypotheses,
  • Or the numerous low-fat campaigns of the American Heart Association, one of whose major donors is the Coca-Cola Company.

Despite the common perception still differs, even the most stubborn health authorities already had to admit that saturated fatty acids are not causing cardiovascular disease (Hite et al. 20101).

Accordingly, studies have shown that saturated fats reduce heart disease while carbohydrates foster them (Mozaffarian et al. 20042).

Furthermore, recent studies suggest that saturated fats can protect against stroke (Siri-Tariano et al. 20103).

A particular type of saturated fat is medium-chain triglycerides (MCT), which you can find in coconut oil and small amounts in butter and palm oil.

These fats can be digested by the body very quickly. When consumed, they find a direct route to the liver. Thus, the body can metabolize MCTs more quickly. Therefore, they have become a famous source of energy.

Coconuts provide good saturated keto fats

Best Keto Foods

You can find healthy saturated fatty acids in these foods:

  • Grass-fed beef
  • Organic lard
  • Grass-fed butter
  • Ghee
  • Whipped cream
  • Free-range eggs
  • Cocoa butter
  • Coconut milk
  • Coconut oil
  • MCT oil

When buying animal fats such as meat, eggs, and dairy products, always go for the highest quality that fits your budget.

With this in mind, meat and dairy products from grass-fed cows or pasture farming have a significantly better fat profile. Thus, this fact is essential when comparing good fats vs. bad fats on keto.

Health Benefits

Healthy saturated fatty acids can bring the following benefits to your diet:

Especially the storage hormone insulin, which is responsible for weight gain, is balanced naturally by the consumption of good fats.

Additionally, MCT oils, which the body can burn exceptionally quick, have the following health benefits (Mumme et al. 20159):

  • Enhanced cognition
  • Improved athletic performance
  • Improved gut health
  • Immune system boost
  • Reduced risk of heart disease
  • Satiety

Good Monounsaturated Fats for Keto

In contrast to saturated fats, monounsaturated fatty acids have already been enjoying good faith for quite a while.

Since countless studies have associated them with health benefits such as improved blood lipid levels or better insulin sensitivity, MUFAs are known as good keto fats (Garg et al. 200710).

Best Keto Foods

Because monounsaturated fats are an integral part of the Mediterranean diet, you can find them in many foods that are generally considered healthy (Mashek et al. 201511):

  • Avocados and avocado oil
  • Extra virgin olive oil
  • Macadamia nuts
  • Pecans
  • Goose fat
  • Organic Lard
  • Bacon

Health Benefits

After monounsaturated fats provide the following variety of health benefits, they are widely known to be healthy (Kris-Etherton et al. 199912; Paniagua et al. 200713):

  • Elevated HDL cholesterol
  • Less abdominal fat
  • Reduced risk of cardiovascular disease
  • Improved hypertension
  • Reduced insulin resistance

Good Polyunsaturated Fats for Keto

When comparing bad fats vs. good fats on keto, we can find polyunsaturated fatty acids on both sides.

Thus, this a complex topic. Therefore, I will keep it short and go into the most critical points.

Accordingly, probably the most essential knowledge applies to the use of polyunsaturated fats because they can quickly oxidize when heated and form free radicals.

And these harmful compounds increase the risk of cancer, cardiovascular disease, and inflammation in the body (Moya Moreno et al. 199914).

Therefore, eat polyunsaturated fats cold (e.g., salad dressings) and do not expose them to light, heat, or pressure. Consequently, please do not use them for cooking.

Because you will find them in unhealthy refined vegetable oils and healthy natural fats as well, polyunsaturated fatty acids are a double-edged sword.

Despite that the ones are more anti-inflammatory and the others more pro-inflammatory, both omega-3 and omega-6 fatty acids are considered essential.

Since the body cannot produce them, you must supply them through food. For this reason, the proportion of polyunsaturated fatty acids is crucial.

Ideally, your ratio of omega-3 to omega-6 fatty acids would be 1:1. Due to the predominant Western Pattern Diet (WPD), the average rate is a pro-inflammatory 1:17.

With researchers suggesting a ratio of at least 1:2 for good health, the goal of any diet, not just ketogenic diets, should be to incorporate more omega-3 fatty acids.

Best Keto Foods

Here is an overview of the best foods containing polyunsaturated fatty acids:

  • Flaxseed
  • Walnuts
  • Fatty fish
    • Herring
    • Anchovies
    • Sardines
    • Mackerel
    • Wild Salmon
  • Fish Oil
  • Krill Oil

However, there is also a variety of industrially produced seed and vegetable oils, which you can find as a list in the bad fats section.

Health Benefits

Among the benefits of many polyunsaturated fats, and omega-3 fatty acids, in particular, is the reduction of following risks (Li et al. 201915; Banaschewski et al. 201816):

  • Cardiovascular diseases
  • Strokes
  • Autoimmune diseases
  • Inflammations
  • Depressions
  • ADHD

Good Trans Fats for Keto

Although it is confusing at first glance, when comparing good fats vs. bad fats on keto, you can find some trans fats on the healthy side.

However, trans fats represent bad fats too.

While artificial trans fats are unhealthy and harmful, there is one type of trans fat that can provide outstanding benefits for your health. It is called conjugated linoleic acids (CLA).

Bad fats vs. good fats on keto - grass-fed beef

Best Keto Foods

This natural trans fat is produced by fermentation in the digestive tract of cows, goats, and sheep.

Accordingly, you can find conjugated linoleic acid in pasture products, which are excellent for ketogenic nutrition:

  • Grass-fed beef
  • Grass-fed heavy cream
  • Goat cheese
  • Pecorino cheese
  • Grass-fed butter
  • Grass-fed ghee

Health Benefits

To deliver the many health benefits of CLA, the animals must nourish themselves on grasses appropriate to their natural diet. For this reason, pasture products contain six times as much conjugated linoleic acid than grain-fed dairy (Dhiman et al. 199917).

Thus, conjugated linoleic acid can provide outstanding health benefits (McCrorie et al. 201118; Daley et al. 201019; Pariza et al. 200020):

  • Conservation of lean mass
  • Reduction of body fat
  • Reduced risk of diabetes
  • Protection against cardiovascular diseases
  • Reduction of blood clots
  • Protection against arteriosclerosis

Also, scientists have discovered a second natural trans fat in the same ruminants that can yield similar health benefits.

For example, vaccenic acid is associated with reducing the risk of cancer, heart disease, diabetes, obesity, and LDL cholesterol levels (Field et al. 200921; Wang et al. 200822).

What Are Bad Fats for Keto?

One of the significant advantages of a high-fat, ketogenic diet is that it promotes satiety.

Nevertheless, it is important to compare good vs. bad fats on keto and eventually eliminate the latter from your meal plan.

Accordingly, unhealthy fats can not only have harmful effects but also do not keep you full in the same manner.

Hydrogenated Fats and Trans Fats

Since industrially processed trans fats can harm health, they rightly enjoy a bad reputation.

Hydrogenated fats are processed polyunsaturated fats. The chemical process enriches vegetable fats with hydrogen atoms to make them shelf-stable.

Therefore, heat-sensitive polyunsaturated omega-6 fatty acids from plants become artificial trans fats.

Foods to Avoid

For example, you will find these trans fats to avoid in:

  • Hydrogenated and partially hydrogenated vegetable oils and fats
  • Crackers
  • Cookies
  • Margarine
  • Mayonnaise
  • French fries
  • Fast food

Health Risks

The risks of eating artificial trans-fatty acids include (Dhaka et al. 201123):

  • Weight gain and increased body fat
  • Cardiovascular diseases
  • Reduced HDL cholesterol
  • Increased risk of cancer
  • Weakened intestinal flora
  • Inflammations in the body
deep-frying - differences between good fats vs bad fats on keto

Refined Seed and Vegetable Oil

Since “plant-based” is increasingly confused with “healthy,” special attention is paid to vegetable and seed oils.

Because polyunsaturated vegetable oils oxidize under the influence of light, heat, and pressure, their industrial processing generates harmful free radicals.

Accordingly, refined vegetable oils already have adverse health effects without further processing into trans fats.

Therefore, not only refined vegetable oils but also trans fats are often produced from oils containing genetically modified seeds.

For example, this is not unlikely to happen with the world’s three most frequently genetically manipulated crops: Corn, soy, and canola.

Foods to Avoid

For this reason, here is a list of industrially processed seed and vegetable oils to avoid:

  • Cottonseed oil
  • Safflower oil
  • Corn germ oil
  • Rapeseed oil
  • Sesame Oil
  • Soybean oil
  • Sunflower oil
  • Grape seed oil

Health Risks

The consumption of formerly stated vegetable and seed oils can have the following adverse health effects (Ramsden et al. 201324; Moran 200125; Gradinaru et al. 201526; Hennig et al. 200127):

  • Inflammation
  • Cardiovascular diseases
  • Dysfunctions in cells
  • Oxidation of LDL cholesterol
  • Hypertension
  • Atherosclerosis
  • Generally increased mortality

Good Fats vs. Bad Fats for Keto

High-quality fats are an important – if not the most important – part of any diet. And this fact is not limited to low-carb or ketogenic diets.

proofread by grammarly

Suppose you incorporate healthy fats like avocados, extra virgin olive oil, grass-fed beef, and dairy into your diet. In that case, you will benefit from health advantages with or without the keto diet.

You are what you eat, especially regarding good fats vs. bad fats on keto. Since fats are the essential building blocks of our cells consist, this statement is more than real.

Therefore, I would think twice before feeding my body with vegetable oil that has already been damaged during industrial processing.

Instead, contrary to common belief, it often makes sense to resort to saturated fat because of its heat resistance. For this reason, saturated fats are better suited for frying than most vegetable oils.

Furthermore, it’s vital to avoid refined vegetable and hydrogenated fats. For example, these artificial trans fats find their way into your body through margarine, mayonnaise, or crackers.

Good Fats vs. Bad Fats for Keto FAQ

Which fats are the good fats?

Natural foods contain good fats. For example, you can find good fats in avocados 🥑, flaxseed, or salmon 🐟.

What are the difference between good fats and bad fats?

The difference between good and bad fats is that the former reduces inflammation risk of cardiovascular disease, and cancer, while the latter promotes these conditions.

What is the healthiest type of fat to eat?

Arguably marine omega-3 fatty acids are the healthiest type of fat to eat. They help you lose weight, gain muscle, and fight inflammation. For example, you can find them in fatty fish such as mackerel 🐟.

Do good fats make you fat?

Good fats such as omega-3 fatty acids or medium-chain triglycerides help burn fat. Refined carbohydrates make you fat. For this reason, you use grains, not fat, to fatten livestock 🐖.



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Mag. Stephan Lederer, MSc.

Mag. Stephan Lederer, MSc. is an author and blogger from Austria who writes in-depth content about health and nutrition. His book series on Interval Fasting landed #1 on the bestseller list in the German Amazon marketplace in 15 categories.

Stephan is a true man of science, having earned multiple diplomas and master's degrees in various fields. He has made it his mission to bridge the gap between conventional wisdom and scientific knowledge. He precisely reviews the content and sources of this blog for currency and accuracy.

Click on the links above to visit his author and about me pages.

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