What is fat fasting

Today it can be hard to keep track with all the trendy diets like low-carb, keto, and intermittent fasting. It can also be hard to figure out what might actually work for you. Furthermore, plenty of these diets have all sorts of versions, including fat fasting.

While the name sounds a little counterintuitive, this diet actually involves upping your fat intake. However, you can only be on this diet for a short period of time.

Also read: Side effects of overeating

What is fat fasting?

Fat fast is not technically a “fast”, but it is referred to as one since the body is forced into a state of ketosis. It involves a splendid mechanism to increase the blood molecules that are known as ketones. This happens because the high-fat, low-carbohydrate intake makes your body burn fat for energy.

In ketosis, your body uses fat as its main energy source instead of carbs, and that way mimicking the biological effects of fasting. During ketosis, liver breaks down fatty acids into molecules called ketones, which can be used to fuel your body when glucose isn’t available.

Fat fasting is restricting both your calorie and carb intake. It pushes your body into ketosis by raising your blood levels of molecules called ketones. That way it helps you to get into ketosis quickly or to increase ketone levels if you have already achieved ketosis.

This diet is usually for people who are already on a ketogenic diet. It is useful for breaking weight loss plateaus or getting back into ketosis after a cheat day. On the other hand, it can also be good for losing a few pounds quickly, without hunger or cravings.

People consult with different doctors, especially nutritionists, for proper results of this diet.

Dietitian recommendation for fat fasting

According to the recommendations, for effective results, you should intake 1,000 to 2,000 calories per day. The major portion of these calories should come from fats.

This diet puts your body in the biological state of ketosis. In the state of ketosis, the body uses fats as an energy source. During the period of this diet, the body does not use energy from carbs. Then, our liver breaks the fatty acids molecules and convert them into ketones. These ketones then act as fuel for the body.

  • Ketones form in the body when glucose is absent. In the absence of glucose, ketones are used by the body as a source of energy
  • We should keep in mind that 80-90% of the calorie intake in our body should come from the fats in this diet

Chemistry of fat burning?

There is a complex biochemical reaction in our body for fat burning. In fat-burning, atoms that make the triglycerides diminish from the body.

Fat burning starts with this chemical equation, which portrays what happens after you burn an atom of triglyceride, the transcendent fat in a human body:

C55H104O6 + 78 O2 –> 55 CO2 + 52 H2O + Energy

From this equation, we can illustrate that when the mass ends in our body then it converts into carbon dioxide and water. According to the research analysis, during the fat-burning, our body makes 84% of carbon dioxide and 16% of water. So, we can say that due to fat-burning our body produces a huge proportion of carbon dioxide. After the formation of carbon dioxide, our body exhales it in the environment.

Difference between fat fasting and keto-diet

The main purpose of both diets includes the destruction of body fats. There is a little difference between these two diets. Fat fast seems to be very similar to the keto diet and might sound like a quickie keto diet, but it is not actually the same thing.

On fat fast, your calories are restricted to 1,000 to 1,200 per day with 80 to 90 percent coming from fat. This is slightly higher in fat and significantly lower in calories than the standard keto diet. On the other hand, these two diets are similar in that the focus is on increasing fat intake to achieve ketosis.

Here is how the ketogenic works: carbohydrates are restricted to a certain level (20-50 grams of net carbs), then the body starts producing ketones and enters ketosis. Once the body becomes fat-adapted, it uses fat stores and ketones for energy. Your protein intake should still be adequate and based on your individual needs. As for glucose, the body still needs some, but it can produce it via gluconeogenesis according to the needs.

On the other hand, fat fast is a type of diet often recommended for those who are already keto-adapted. Mostly for those who reach a weight loss plateau or want to get back into ketosis after a cheat day, as we mentioned before.

Fat fasting shouldn’t be followed for more than 3-5 days. If you follow it for a longer period, you run the risk of getting side effects. For instance, getting your body into starvation mode, losing muscles and getting deficient in essential nutrients.

Carbohydrates in both diets are recessive. The main purpose of these diets is to burn the fats and help in weight loss.

How does fat fasting help you burn fat?


Now we know that the main calories of fat fasting diet come from fats in food. It works to create the ketone molecules in the body that mainly results from the fats in the food that we eat. This diet promotes the breakage of fatty acids in the liver into ketone molecules.

As we said, fat fast is very low in calories and high in fat. It’s designed to quickly decrease the carb stores and create a calorie deficit. If you adhere to fat fasting for 2-5 days, you may begin burning fat as your primary source of fuel due to entering ketosis. Especially if you are already on a low-carb diet because, in that case, a fat fast may also boost your ketone levels. Therefore, you lose weight because of the calorie deficit itself, but also by moving your body into ketosis and burning more fat.

Nevertheless, huge weight loss can’t be explained by fat loss alone as a fat fast only lasts a few days. The reason for large shifts on the scale is because of a loss of water.

Water is stored alongside glycogen, the stored form of glucose, so when you lose glycogen you also lose water. In fact, if you’re not already keto-adapted or you’re doing a fat fast after a cheat day, you may think that you lost fat, but a lot of the weight lost during a fat fast is likely water weight.

In conclusion, as soon as you begin eating carbs again and replace your body’s glycogen stores, the weight (water weight) will return.

Fat fasting effects

Approximately, 12 to 24 hours of fasting usually results in a 20% diminish in serum glucose. It also results in the consumption of the hepatic glycogen, which switches to a metabolic model.

Discontinuous metabolic exchanging from carb-burning to fat-burning has been appeared to be advantageous for weight loss. It is also helpful for nervous control management.

A case study of fat fasting

In 2017, stout people who limited their eating window to 8 hours for 12 weeks misplaced 3% of their body weight. One major advantage of restricting your eating window to 6-8 hours a day is that you simply don’t ought to keep tally of your calories.  

Most think about irregular fasting utilizing the 5:2 slim down convention or negligible calorie fasting days have detailed measurably weight misfortune, around identical to what can be accomplished through persistent calorie confinement.

Detailed weight misfortune results of the 5:2 count calories run from 3.2% weight misfortune. In comparison to a control gather over 12 weeks to 8.0% weight misfortune in an 8-week trial enlisting overweight grown-ups with asthma.

When to consider the fat fast

You should use fat fast only if you are already keto-adapted. Otherwise, it will be very difficult for you to follow the diet, because your body is not used to the low-carb diet and increased ketone levels.

If you are not keto-adapted, try following the ketogenic diet for a few weeks and use the fat fast technique in the following situations:

Weight loss plateau

Use the fat fast technique if for any reason your weight is stalling for more than 2-3 weeks. However, before you jump into fat fasting, make sure that you have eliminated all the potential reasons for the weight loss plateau. Check your keto ratio to eliminate the most common reasons for weight stalling. For instance, too many carbs or an inadequate amount of protein, fats, or calories in your diet.

After a “cheat day”

You can also use the fat fast technique if you had a “cheat day” and would like to get back on track the next day. It is not necessary to use the fat fast for this situation but it is up to you. Instead of fat fast, which gives the body a calorie shock, dietitians recommend to just keep eating healthy, low-carb foods from the day following a “cheat day”.

Adapt the fat fast by following these tips

  • Increase fiber intake for betterment in the health of the gut.
  • Stick to your daily calories aim.
  • Avoid daily heavy meals and snacks.
  • Eat restrictedly.
  • Eliminate the added sugars.
  • Eat more fruits and vegetables.

What to eat on a fat fast?

Avocado and salmon dish

Although there is not much choice you have, considering that you have to eat a lot of fat and keep the calories low, it’s up to you what you will be eating.

The majority of the calorie intake in this diet, 80-90% should be high-fat foods. Try to eat foods that are almost pure fat. For instance: avocado, macadamia nuts, cream cheese, fat bombs.

You can also add a little meat in your diet, but keep the amount of it low. High-protein foods like meat, chicken, and fish are normally consumed in moderate amounts on a ketogenic diet, but these are not often included during a fat fast. Meat is a protein, which you want to be sparing, but you still need to get a bit of protein in your system. Also, it adds some extra flavor to your dishes.

Foods that are high in carbs and protein and low in fat are limited during a fat fast.

What to eat

  • High-fat meats and fish: bacon, sardines, and salmon
  • Eggs: whole eggs and egg yolks
  • Oils and high-fat spreads: coconut oil, mayonnaise (healthy oil base), olive oil, and avocado oil, MCT oil, macadamia nut oil
  • High-fat nuts and nut butters: macadamia nuts, macadamia nut butter, etc.
  • Low-carb vegetables and high-fat fruits: avocados, olives, and non-starchy vegetables like kale, spinach, and zucchini that have been cooked in fat.
  • High-fat dairy: butter, ghee, cream cheese, heavy cream, and high-fat cheese like brie
  • High-fat, nondairy products: full-fat coconut milk and coconut cream
  • Drinks: water, tea, coffee, and sparkling water
  • Fluid foods such as bone broth and coffee
  • You can use spices

What to avoid

  • Cereals and grains: breads, pasta, crackers, cereal, oats, rice, etc.
  • Beans and pulses: lentils, black beans, butter beans, etc.
  • Most fruits and vegetables: avoid all except those listed above
  • Low-fat dairy foods: skim milk, low-fat cheese, low-fat yogurt, etc.
  • Low-fat meats and fish: chicken, beef, lamb, cod, etc.
  • Cakes and confectionaries: sweets, biscuits, cakes, pastries, etc.
  • Sweet drinks: juice, energy drinks, sweetened coffee, etc.

Do fat bombs help you lose weight?

Fat bombs are so high in fat and low in protein that they will assist you to burn more fat for fuel and remain in ketosis. This gives ketogenic count calories newcomers with a ketosis kick begin and long term ketogenic dieters with an increment in vitality and weight loss.

Fat Bombs Chemistry

Fat bombs are a tasty combination of ketogenic fixings that you simply can have as a nibble, dessert, or feast substitution. They contain over 90% fat, are simple to form, and come in an assortment of distinctive flavours.

Indeed, fat bombs that contain high-fat dairy have special wellbeing benefits since they contain vitamins, minerals, and a greasy corrosive called conjugated linoleic corrosive (CLA). This greasy corrosive has been found to avoid heart malady, increment safe work, and diminish body fat.

Fat Bombs and Fats Fasting

You can include natural products to your fat bombs! But be sure to remember it is a low-carb natural product like blueberries. Putting a few blueberries in a chocolaty fat bomb may be an extraordinary way to include normal sweetness and wellbeing benefits (simply won’t get from sucralose or erythritol).

Numerous low-carb natural products like blueberries contain anthocyanins which are effective cancer prevention agents that secure the body from heart illness and cancer, and may indeed boost cognitive work.

Fat bombs products

Nuts and seeds can give protein, fat, and fiber that is lost with your fat bombs. Seeds like flaxseeds, sesame seeds, and chia seeds too have a tall lignan substance, which secures us from irritation, carcinogens, and cancer.

To induce these benefits, all you have to do is include them in your fat bomb. The most popular seed to discover in fat bombs isn’t flaxseeds, sesame seeds, or chia seeds. It is the cacao bean.

Even though you won’t discover the cacao bean (the seed of the cacao tree) in numerous fat bomb formulas, it’s utilized in its powdered frame (cacao powder) in numerous keto-friendly treats.

Important fat bombs

  • Fall season fat bomb
  • No-bake chocolate butter fat bombs
  • Neapolitan fat bombs
  • Coconut orange creamsicle fat bombs
  • Neapolitan fat bombs
  • Coconut orange creamsicle fat bombs
  • Savory pizza fat bombs
  • Jalapeno popper fat bombs

Some ingredients to add into the fat bombs:

  • Cacao powder
  • Vanilla
  • Coconut flakes
  • Low-carb maple syrup
  • Nuts
  • Nut butter/flours
  • Seeds (like flaxseed, chia seeds, or hemp seeds)
  • Cinnamon
  • Berries (like blackberries or blueberries)
  • Bacon bits
  • Eggs
  • Chopped cooked meat (like salami, salmon, or steak)
  • Chopped herbs
  • Low-carb vegetables (like scallions or onions)
  • Low-carb fruits (like wild blueberries or tomatoes)
  • Cheese
  • Heavy cream
  • Sour cream
  • Coconut cream
  • Lemon juice

Is fat fasting healthy?

Fat fasting shouldn’t be followed long term as it requires a diet plan that is low in calories, protein, carbs, and some micronutrients. Furthermore, because the essential nutrients are missing, it can be bad for health.

Low-carb, high-fat diets, like keto-diet, have been shown to promote weight loss and improve some health markers. For instance, if followed properly, it may :

  • Prevent heart attack and heart failure
  • Prevent many tumors and cancers
  • Be beneficial for skin problems and acne
  • Improve blood sugar levels
  • Prevent epilepsy
  • Be effective for the nervous system
  • Control and treat the polycystic ovary syndrome

However, fat fasting isn’t the same as a ketogenic diet. A standard ketogenic diet typically contains 75% fat, 20% protein, and 5% carbs. In contrast, fat fasting is higher in fat and lower in carbs and protein, and its effects on health are not well studied.

In conclusion, many questions about fat fasting remain unanswered. What risks are associated with using this method? What types of fat may be optimal for this technique? Therefore, if you decide to try fat fasting, only follow this plan for 2–5 days, as we already said it lacks important nutrients.

Side effects and risks of fat fasting

Fat fasting side effects

If you’re not following a ketogenic diet before doing a fat fast, you may experience side effects.

The most common side effect is the keto flu. You may experience keto flu when your body first goes into ketosis. This is a number of symptoms that include headaches, fatigue, dizziness, nausea, vomiting, fainting, poor sleep, difficulty exercising, diarrhea, and constipation, all stemming from extreme carbohydrate restriction.

Although a fat fast is a short-term diet, it’s possible that you could experience the same symptoms. These symptoms usually last a few days to several weeks.

Furthermore, fat fasting is extremely restrictive in nutrients. Therefore, if you don’t stick to the recommended period of following the diet, it may lead to nutrient deficiencies and other side effects.

Due to the lack of protein and calories, following this diet in a longer duration may put you at risk of muscle wasting. Muscle wasting occurs because the body needs more protein and energy so it starts to break down muscles to meet his needs.

In some rare cases, you may experience more side effects which are the same as the potential side effects of the keto diet.

Avoid doing this diet, or any low-carb diet, without medical supervision. Especially if you are taking medications or have a condition like heart disease or diabetes. Also, if you start to feel unwell at any point during a fat fast, stop the diet and contact your healthcare provider.

There is no research on the safety of fat fasting, and it is unclear whether it provides any benefits for weight loss or overall health. Therefore, we don’t recommend this technique for women who are pregnant or breastfeeding. Also, if you hyper-respond to cholesterol, avoid this diet as it may lead to a significant increase in cholesterol levels.


Weight misfortune may be the most important wellbeing objective. Whereas fasting or supplement limitation is regularly a compelling way of accomplishing weight misfortune, there are other ways of life variables that are key to keeping up your metabolic wellbeing long-term. These incorporate things like work out, satisfactory rest, and push management.

But, as fats are very saturated, the fat fast may help you to battle you’re craving to eat and your carbohydrate desires. Over time you may discover that it takes less to satisfy you, and you may begin fasting naturally which will help you lose weight. 

Nevertheless, we can’t recommend you to try this diet as the research is still lacking. It’s unknown whether this highly restrictive method is effective or safe, and the potential risks associated with this eating pattern are unknown. Additionally, it’s unclear whether fat fasting provides any benefits for weight loss or wellbeing at all.

Thus, it may be safer to not follow the fat fasting until more research is done.

Also read: 8 best foods to help control diabetes


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