Extreme diets: why would you want to embrace a very-low-carb or an ultra-low-fat diet?

In my past life as a fanatical long-distance cyclist, it struck me how my fellow cyclists were always talking about equipment and wanting to acquire the lightest possible yet sturdiest bike possible. In the meantime, nutrition was rarely discussed.
Which made me rather frustrated and decide to take up an interest in bodybuilding as those guys and girls for sure would know how to increase their performance while eating healthy?

Errr, not so much! Yes, indeed, bodybuilders knew how to achieve their goals, but they also knew very well 'hormonally enhance their body' by gobbling or inserting anabolic steroids.
Fortunately there are also lots of fitness-oriented people who want to improve their looks without resorting to hormonal enhancement.
Essentially, there's the task to lose fat without losing muscle by eating less calories than you need, and yet keep performing well in the gym or outside on your road bike.
Fitness folks solved the puzzle on how to lose fat without losing the ability to perfum by eating as few calories as possible on most days by eliminating both carbs and fats as much as possible to be followed by a very high carb refeed in order to replenish glycogen stores. Or they may have a few unstructured 'free meals' to keep spirits up.

In the meantime, the cycling world changed dramatically with the arrival of personalized food plans, in which especially the team Jumbo-Visma made the greatest progress! From following various cycling news sites as well as podcasts, the current stance to increase performance is to train yourself in eating as many carbs as possible while on the bike! This is more difficult than you imagine, since very intensive exercise drastically decreases blood flow to the intestines and decreases digestion capacity!

As a further refinement, pro cyclists revealed in a cycling podcast how the Jumbo-team would change to a very low-fiber diet prior to strenuous mountain stages, so cyclists wouldn't need to drag one more kilogram of poop uphill! And return to a moderate-fiber diet afterwards. 

Imagine my surprise when shortly thereafter, an acquaintance returned to our perfume group after a very long absence in which she hadn't just been banned from wearing perfume , but had also been told to eat a very strict low-fiber high-carb diet! The reason wasn't very funny, she had underwent surgery and chemotherapy for a colon cancer. These are two very different reasons to go low-fiber with the same outcome.

Which is why I'd like to discuss various types of extreme diets and reveal why it makes sense to follow them. And more specifically whether there are medical reasons to do so.

It's more difficult to find good information than you imagine as most articles are simply written for entertainment.

For a good laugh: the 10 craziest diets you've never heard of  

Due to a lack of time, let's focus on just two extreme diets, very low-carb diets versus very ultra-fat diets.

Usefulness of keto diets

Unlike what many of you may think, the keto diet which is also known as the Atkins diet named after dr Atkins a cardiologist who popularized it in the 1970s , has been in existence far longer than you think.
The very first person to popularize an extremely low-carb diet, was William Banting (1796-1878). Banting authored a booklet that detailed his plan. His booklet was so popular that "banting" became a term for dieting. At the time, knowledge on biology and biochemistry was so limited, mr Banting had no idea on the concept of ketosis.
However this changed when it became apparent in the 20th century a very low carb diet could prevent or diminish the severity of epileptic seizures.

That's not the only medical condition for which following a ketogenic diet may be beneficial.

15 Health conditions that may benefit from a ketogenic diet

Ketogenic diets have become incredibly popular.
Early research suggests this high-fat, very low-carb diet may benefit several health conditions.

Although some of the evidence is from case studies and animal research, results from human controlled studies are also promising.

1. Epilepsy

Epilepsy is a disease that causes seizures due to excessive brain activity.

Anti-seizure medications are effective for some people with epilepsy. However, others don’t respond to the drugs or can’t tolerate their side effects.
Of all the conditions that may benefit from a ketogenic diet, epilepsy has by far the most evidence supporting it. In fact, there are several dozen studies on the topic.
Research shows that seizures typically improve in about 50% of epilepsy patients who follow the classic ketogenic diet. This is also known as a 4:1 ketogenic diet because it provides 4 times as much fat as protein and carbs combined.

The modified Atkins diet (MAD) is based on a considerably less restrictive 1:1 ratio of fat to protein and carbs. It has been shown to be equally effective for seizure control in most adults and children older than two years of age.

The ketogenic diet may also have benefits on the brain beyond seizure control.

For example, when researchers examined the brain activity of children with epilepsy, they found improvements in various brain patterns in 65% of those following a ketogenic diet — regardless of whether they had fewer seizures.
Conclusion: ketogenic diets have been shown to reduce seizure frequency and severity in many children and adults with epilepsy who don’t respond well to drug therapy.

2. Metabolic syndrome

Metabolic syndrome, sometimes referred to as prediabetes, is characterized by insulin resistance.

You can be diagnosed with metabolic syndrome if you meet any 3 of these criteria:

- large waistline: 89 cm or higher in women and 102 cm or higher in men.
- elevated triglycerides: 150 mg/dl (1.7 mmol/L) or higher.
- low HDL cholesterol: Less than 40 mg/dl (1.04 mmol/l) in men and less than 50 mg/dL (1.3 mmol/l) in women.
- high blood pressure: 130/85 mm Hg or higher.
- elevated fasting blood sugar: 100 mg/dL (5.6 mmol/l) or higher.

People with metabolic syndrome are at increased risk of diabetes, heart disease and other serious disorders related to insulin resistance.
Fortunately, following a ketogenic diet may improve many features of metabolic syndrome. Improvements may include better cholesterol values, as well as reduced blood sugar and blood pressure.

In a controlled 12-week study, people with metabolic syndrome on a calorie-restricted ketogenic diet lost 14% of their body fat. They decreased triglycerides by more than 50% and experienced several other improvements in health markers.

Conclusion: ketogenic diets may reduce abdominal obesity, triglycerides, blood pressure and blood sugar in people with metabolic syndrome.

3. Glycogen Storage Disease

People with glycogen storage disease (GSD) lack one of the enzymes involved in storing glucose (blood sugar) as glycogen or breaking glycogen down into glucose. There are several types of GSD, each based on the enzyme that is missing.

Typically, this disease is diagnosed in childhood. Symptoms vary depending on the type of GSD, and may include poor growth, fatigue, low blood sugar, muscle cramps and an enlarged liver.
GSD patients are often advised to consume high-carb foods at frequent intervals so glucose is always available to the body.

However, early research suggests that a ketogenic diet may benefit people with some forms of GSD.
For example, GSD III, also known as Forbes-Cori disease, affects the liver and muscles. Ketogenic diets may help relieve symptoms by providing ketones that can be used as an alternate fuel source.
GSD V, also known as McArdle disease, affects the muscles and is characterized by a limited ability to exercise.
In one case, a man with GSD V followed a ketogenic diet for one year. Depending on the level of exertion required, he experienced a dramatic 3- to 10-fold increase in exercise tolerance.
However, controlled studies are needed to confirm the potential benefits of ketogenic diet therapy in people with glycogen storage disease.

Conclusion: people with certain types of glycogen storage disease may experience a dramatic improvement in symptoms while following a ketogenic diet. However, more research is needed.

4. Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a disease marked by hormonal dysfunction that often results in irregular periods and infertility.

One of its hallmarks is insulin resistance, and many women with PCOS are obese and have a hard time losing weight. Women with PCOS are also at an increased risk for type 2 diabetes.

Those who meet the criteria for metabolic syndrome tend to have symptoms that affect their appearance. Effects may include increased facial hair, acne and other signs of masculinity related to higher testosterone levels.

A lot of anecdotal evidence can be found online. However, only a few published studies confirm the benefits of low-carb and ketogenic diets for PCOS.

In a 6-month study of eleven women with PCOS following a ketogenic diet, weight loss averaged 12%. Fasting insulin also declined by 54% and reproductive hormone levels improved. Two women suffering from infertility became pregnant.

Conclusion: women with PCOS following a ketogenic diet may experience weight loss, reduction in insulin levels and improvement in reproductive hormone function.

5. Diabetes

People with diabetes often experience impressive reductions in blood sugar levels on a ketogenic diet. This is true of both type 1 and type 2 diabetes.

Indeed, dozens of controlled studies show that a very low-carb diet helps control blood sugar and may also provide other health benefits.

In a 16-week study, 17 of 21 people on a ketogenic diet were able to discontinue or decrease diabetes medication dosage. Study participants also lost an average of 8.7 kg and reduced their waist size, triglycerides and blood pressure.

In a 3-month study comparing a ketogenic diet to a moderate-carb diet, people in the ketogenic group averaged a 0.6% decrease in HbA1c. 12% of participants achieved an HbA1c below 5.7%, which is considered normal.
Conclusion: ketogenic diets have been shown to reduce blood sugar in people with diabetes. In some cases, values return to a normal range, and medications can be discontinued or reduced.

6. Some cancers

Cancer is one of the leading causes of death worldwide.
In recent years, scientific research has suggested that a ketogenic diet may help some types of cancer when used along with traditional treatments such as chemotherapy, radiation and surgery.

Many researchers note that elevated blood sugar, obesity and type 2 diabetes are linked to breast and other cancers. They suggest that restricting carbs in order to lower blood sugar and insulin levels may help prevent tumor growth.

Mice studies show ketogenic diets may reduce the progression of several types of cancer, including cancers that have spread to other parts of the body .

However, some experts believe the ketogenic diet may be particularly beneficial for brain cancer.

Case studies and patient data analyses have found improvements in various types of brain cancer, including glioblastoma multiforme (GBM) — the most common and aggressive form of brain cancer.

One study found 6 out of 7 GBM patients had a modest response to an unrestricted-calorie ketogenic diet combined with an anti-cancer drug. Researchers noted that the diet is safe but probably of limited use alone.

Some researchers report preservation of muscle mass and slowed tumor growth in cancer patients who follow a ketogenic diet in conjunction with radiation or other anti-cancer therapies.

Although it may not have a significant impact on disease progression in advanced and terminal cancers, the ketogenic diet has been shown to be safe in these patients and potentially improve quality of life.

Randomized clinical studies need to examine how ketogenic diets affect cancer patients. Several are currently underway or in the recruiting process.

Conclusion:animal and human research suggests ketogenic diets may benefit people with certain cancers, when combined with other therapies.

7. Autism

Autism spectrum disorder (ASD) refers to a condition characterized by problems with communication, social interaction and, in some cases, repetitive behaviors. Usually diagnosed in childhood, it is treated with speech therapy and other therapies.

Early research in young mice and rats suggests ketogenic diets may be helpful for improving ASD behavior patterns.
Autism shares some features with epilepsy, and many people with autism experience seizures related to the over-excitement of brain cells.

Studies show that ketogenic diets reduce brain cell over-stimulation in mouse models of autism. What’s more, they appear to benefit behavior regardless of changes in seizure activity.

A pilot study of 30 children with autism found that 18 showed some improvement in symptoms after following a cyclical ketogenic diet for 6 months.

In one case study, a young girl with autism who followed a gluten-free, dairy-free ketogenic diet for several years experienced dramatic improvements. These included resolution of morbid obesity and a 70-point increase in IQ.

Randomized controlled studies exploring the effects of a ketogenic diet in ASD patients are now underway or in the recruiting process.

Conclusion:early research suggests some people with autism spectrum disorders may experience improvements in behavior when ketogenic diets are used in combination with other therapies.

8. Parkinson’s Disease

Parkinson’s Disease (PD) is a nervous system disorder characterized by low levels of the signaling molecule dopamine.
The lack of dopamine causes several symptoms, including tremor, impaired posture, stiffness and difficulty walking and writing.

Because of the ketogenic diet’s protective effects on the brain and nervous system, it’s being explored as a potential complementary therapy for PD.

Feeding ketogenic diets to rats and mice with PD led to increased energy production, protection against nerve damage and improved motor function.

In an uncontrolled study, seven people with PD followed a classic 4:1 ketogenic diet. After 4 weeks, five of them averaged a 43% improvement in symptoms.

The effects of a ketogenic diet on PD is another area that needs controlled studies.

Conclusion:the ketogenic diet has shown promise in improving symptoms of Parkinson’s disease in both animal and human studies. However, high-quality research is needed.

9. Obesity

Many studies show that very low-carb, ketogenic diets are often more effective for weight loss than calorie-restricted or low-fat diets.
What’s more, they typically provide other health improvements as well.
In a 24-week study, men who followed a ketogenic diet lost twice as much fat as men who ate a low-fat diet.

In addition, the ketogenic group’s triglycerides dropped significantly, and their HDL (“good”) cholesterol increased. The low-fat group had a smaller drop in triglycerides and a decrease in HDL cholesterol.

Ketogenic diets’ ability to reduce hunger is one of the reasons why they work so well for weight loss.

A large analysis found that very low-carb, calorie-restricted ketogenic diets help people feel less hungry than standard calorie-restricted diets.

Even when people on a ketogenic diet are allowed to eat all they want, they generally end up eating fewer calories due to the appetite-suppressing effects of ketosis.

In a study of obese men who consumed either a calorie-unrestricted ketogenic or moderate-carb diet, those in the ketogenic group had significantly less hunger, took in fewer calories and lost 31% more weight than the moderate-carb group.

Summary:studies have found that ketogenic diets are very effective for weight loss in obese people. This is largely due to their powerful appetite-suppressing effects.

10. GLUT1 Deficiency Syndrome

Glucose transporter 1 (GLUT1) deficiency syndrome, a rare genetic disorder, involves deficiency of a special protein that helps move blood sugar into the brain.

Symptoms usually begin shortly after birth and include developmental delay, difficulty with movement and sometimes seizures.

Unlike glucose, ketones don’t require this protein to cross from the blood to the brain. Therefore, the ketogenic diet can provide an alternative fuel source that these children’s brains can use effectively.

Indeed, ketogenic diet therapy seems to improve several symptoms of the disorder. Researchers report decreased seizure frequency and improvement in muscle coordination, alertness and concentration in children on ketogenic diets.

As with epilepsy, the modified Atkins diet (MAD) has been shown to provide the same benefits as the classic ketogenic diet. However, the MAD offers greater flexibility, which may result in better compliance and fewer side effects.

In a study of 10 children with GLUT1 deficiency syndrome, those who followed the MAD experienced improvements in seizures. At six months, 3 out of 6 became seizure-free.

Conclusion: both the classic ketogenic diet and more flexible MAD have been shown to improve seizures and other symptoms in children with GLUT1 deficiency syndrome.

11. Traumatic Brain Injury

Traumatic brain injury (TBI) most commonly results from a blow to the head, a car accident or a fall in which the head strikes the ground.

It can have devastating effects on physical function, memory and personality. Unlike cells in most other organs, injured brain cells often recover very little, if at all.

Because the body’s ability to use sugar following head trauma is impaired, some researchers believe the ketogenic diet may benefit people with TBI.

Rat studies suggest that starting a ketogenic diet immediately after brain injury can help reduce brain swelling, increase motor function and improve recovery. However, these effects appear to occur mainly in younger rather than older rats.

That said, controlled studies in humans are needed before any conclusions can be reached.

Conclusion: animal studies show that a ketogenic diet improves outcomes in rats fed a ketogenic diet after traumatic brain injury. However, there are currently no quality human studies on this.

12. Multiple Sclerosis

Multiple sclerosis (MS) damages the protective covering of nerves, which leads to communication problems between the brain and body. Symptoms include numbness and problems with balance, movement, vision and memory.

One study of MS in a mouse model found that a ketogenic diet suppressed inflammatory markers. The reduced inflammation led to improvements in memory, learning and physical function.

As with other nervous system disorders, MS appears to reduce the cells’ ability to use sugar as a fuel source. A 2015 review discussed ketogenic diets’ potential to assist with energy production and cell repair in MS patients.

Additionally, a recent controlled study of 48 people with MS found significant improvements in quality of life scores, cholesterol and triglycerides in the groups who followed a ketogenic diet or fasted for several days.

More studies are currently underway.

Conclusion:studies about the potential benefits of a ketogenic diet for treating MS are promising. However, more human studies are needed.

13. Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world.

It is strongly linked to type 2 diabetes, metabolic syndrome and obesity, and there’s evidence that NAFLD also improves on a very low-carb, ketogenic diet.

In a small study, 14 obese men with metabolic syndrome and NAFLD who followed a ketogenic diet for 12 weeks had significant decreases in weight, blood pressure and liver enzymes.

What’s more, an impressive 93% of the men had a reduction in liver fat, and 21% achieved complete resolution of NAFLD.

Conclusion:ketogenic diets may be very effective at reducing liver fat and other health markers in people with nonalcoholic fatty liver disease.

14. Alzheimer’s Disease

Alzheimer’s disease is a progressive form of dementia characterized by plaques and tangles in the brain that impair memory.

Interestingly, Alzheimer’s disease appears to share features of both epilepsy and type 2 diabetes: seizures, the inability of the brain to properly use glucose and inflammation linked to insulin resistance.

Animal studies show that a ketogenic diet improves balance and coordination but doesn’t affect the amyloid plaque that is a hallmark of the disease. However, supplementing with ketone esters appears to reduce amyloid plaque.

In addition, supplementing people’s diets with ketone esters or MCT oil to increase ketone levels has been shown to improve several Alzheimer’s disease symptoms.

For example, one controlled study followed 152 people with Alzheimer’s disease who took an MCT compound. After 45 and 90 days, this group showed improvements in mental function, while the placebo group’s function declined.

Controlled studies testing the modified Atkins diet and MCT oil in people with Alzheimer’s disease are currently in progress or in the recruiting stage.

Conclusion:several symptoms of Alzheimer’s disease have been shown to improve with ketogenic diets in animal research. Human studies suggest supplementing with MCT oil or ketone esters may be beneficial.

15. Migraine headaches

Migraine headaches typically involve severe pain, sensitivity to light and nausea.
Some studies suggest migraine headache symptoms often improve in people who follow ketogenic diets.

One observational study reported a reduction in migraine frequency and pain medication use in people following a ketogenic diet for one month.

An interesting case study of two sisters following a cyclical ketogenic diet for weight loss reported that their migraine headaches disappeared during the 4-week ketogenic cycles but returned during the 8-week transition diet cycles.

However, high-quality studies are needed to confirm the results of these reports.

Conclusion:some studies suggest that migraine headache frequency and severity may improve in people following a ketogenic diet.

Summary

Ketogenic diets are being considered for use in several disorders due to their beneficial effects on metabolic health and the nervous system.
However, many of these impressive results come from case studies and need validation through higher-quality research, including randomized controlled trials.
With respect to cancer and several other serious diseases on this list, a ketogenic diet should be undertaken only in addition to standard therapies under the supervision of a doctor or qualified healthcare provider.
Also, no one should consider the ketogenic diet a cure for any disease or disorder on its own.
Nonetheless, the ketogenic diets’ potential to improve health is very promising.

Now onto the other extreme! 

Can an ultra-low-fat diet be healthy?

After having been bombarded in the past decade with stories about the benefits of low-carb diets, it is almost easy to forget how in between the period when a ketodiet became popular in the 70s as well as in the more recent past,fats were vilified and instead , a low-fat diet was embraced.
While extreme low-fats can be very unhealthy as they disturb hormonal balance much more easily than an extreme low-carb diet, there are circumstances at which such an ultra-low-fat diet can be useful or .. gasp, even healthy.

Fat makes up 10% or less of your daily calories when following an ultra-low-fat diet. While this diet may be helpful for those with certain health conditions, it may not be the best option for others.

For decades, official dietary guidelines have advised people to eat a low-fat diet, in which fat accounts for around 30% of your daily calorie intake.
Yet, many studies suggest that this way of eating is not the most effective strategy for weight loss in the long term.

The largest and longest studies show only minimal reductions in weight and no effects on heart disease or cancer risk.

However, many proponents of low-fat diets claiming that these results are flawed, as they consider the 30% recommendation for fat intake insufficient.
Instead, they suggest that — for a low-fat diet to be effective — fat should make up no more than 10% of your daily calories.

This article takes a detailed look at ultra-low-fat diets and their health effects.

What is an ultra-low-fat diet?

An ultra-low-fat — or very-low-fat — diet allows for no more than 10% of calories from fat. It also tends to be low in protein and very high in carbs — with about 10% and 80% of daily calories, respectively.
Ultra-low-fat diets are mostly plant-based and limit your intake of animal products, such as eggs, meat, and full-fat dairy.

High-fat plant foods — including extra virgin olive oil, nuts, and avocados — are also often restricted, even though they’re generally perceived as healthy.
This can be problematic, as fat serves several important functions in your body.
It’s a major source of calories, builds cell membranes and hormones, and helps your body absorb fat-soluble vitamins like vitamins A, D, E, and K.
Plus, fat makes food taste good. A diet very low in fat is generally not as pleasurable as one that’s moderate or high in this nutrient.
Nonetheless, studies show that an ultra-low-fat diet may have very impressive benefits against several serious conditions.

Conclusion: an ultra-low-fat — or very-low-fat — diet provides less than 10% of calories from fat. It limits most animal foods and even healthy high-fat plant foods like nuts and avocados.
Ultra-low-fat diets have been thoroughly studied, and evidence indicates that they may be beneficial against several serious conditions, including heart disease, diabetes, obesity, and multiple sclerosis.

1. Heart disease

Studies show that an ultra-low-fat diet can improve several important risk factors for heart disease, including:

• high blood pressure
• high blood cholesterol
• high C-reactive protein, a marker for inflammation

One study in 198 people with heart disease found particularly striking effects.

Only 1 of the 177 individuals who followed the diet experienced a heart-related event, compared to more than 60% of people who didn’t follow the diet.

2. Type 2 diabetes

Several studies indicate that very-low-fat, high-carb diets can lead to improvements in people with type 2 diabetes.
For example, in a study in people with type 2 diabetes on a very-low-fat rice diet, 63 of 100 participants decreased their fasting blood sugar levels .
What’s more, 58% of individuals who were dependent on insulin before the study were able to reduce or stop insulin therapy completely.

Another study noted that an ultra-low-fat diet may be even more beneficial for people with diabetes who are not already dependent on insulin.

3. Obesity

People who are obese may also benefit from eating a diet that is very low in fat.
The very-low-fat rice diet has been used to treat obese people with impressive results.
One study in 106 massively obese people found that participants on this diet lost 63.5 kg on average — which may seem surprising for a diet mainly consisting of refined carbs.

4. Multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease that affects your brain, spinal cord, and optic nerves in your eyes.
People with this condition may benefit from an ultra-low-fat diet as well.
In 1948, Roy Swank began treating MS with the so-called Swank diet.
In his most famous study, Swank followed 150 people with MS for over 50 years. The results indicate that an ultra-low-fat diet may slow the progression of MS.
After 34 years, only 31% of those who adhered to the diet had died, compared to 80% of those who failed to follow his recommendations

Conclusion: an ultra-low-fat diet may improve risk factors for heart disease and benefit people with type 2 diabetes, obesity, and MS.

Why do ultra-low-fat diets work?

Exactly how or why ultra-low-fat diets improve health is not well understood.
Some argue that the blood-pressure-lowering effects may not even be directly linked to their low fat content.
For example, the rice diet is extremely low in sodium, which may positively affect blood pressure.
Additionally, it’s monotonous and bland, which may cause an unintentional reduction in calorie intake, as people may feel less inclined to eat more of an unrewarding food.
Cutting calories tends to have major benefits for both weight and metabolic health — no matter whether you’re cutting carbs or fat.

Summary

Though it’s not fully understood why ultra-low-fat diets have powerful health benefits, it may be related to drastically reduced calorie intake rather than decreased fat specifically.
An ultra-low-fat diet may help treat serious conditions, including diabetes and heart disease.
However, following a strict diet very low in fat is extremely hard in the long run, as it’s unenjoyable and lacks variety.
You may even have to limit your intake of very healthy foods, such as unprocessed meat, fatty fish, eggs, nuts, and extra virgin olive oil.
While this diet may benefit certain individuals with serious health conditions, it’s likely unnecessary for most people.

Our conclusion: as you will have noticed, there are far fewer medical issues for which a very low-fat diet may be use among which two (obesity and multiple sclerosis may also improve while applying a very low-carb diet! We know which one we would choose for ourselves in such cases!