Keto Diet: Healthy Weight Loss Or Health Hazard?

The ketogenic diet is a low-carbohydrate, high-fat eating plan that has been linked to several health benefits, including weight loss, increased energy, and improved management of chronic illnesses such as epilepsy, Alzheimer's, and type 2 diabetes. However, there are also concerns about potential risks and side effects associated with the keto diet. Some people have reported negative experiences, including increased LDL cholesterol, constipation, nutrient deficiencies, liver and kidney problems, and even claims that the diet almost killed them. While the keto diet may offer benefits for some, it is not without its drawbacks, and it is important to consult a doctor and a registered dietitian before making any significant dietary changes.

Keto may increase your risk of heart disease

The ketogenic diet is a low-carbohydrate, high-fat diet that has gained popularity in recent years. While it has been used to manage epilepsy and control seizures in children who don't respond well to other treatment methods, there are concerns about its safety.

The ketogenic diet and heart health

A new study has found that keto and keto-like diets may be linked to a higher risk of heart disease, raising LDL ("bad") cholesterol levels and doubling the risk of cardiovascular events such as heart attacks and strokes.

The ketogenic diet typically contains 60-80% fat, 20-30% protein, and only 10% carbohydrates. This means cutting out almost all sources of carbohydrates, including fruit, starchy vegetables, grains, beans, legumes, sugar, and alcohol. Instead, dieters rely on fat sources such as nuts, oils, butter, cream, and cheese to keep them full.

The current dietary guidelines for Americans suggest eating less than 10% of total calories from fat. A keto diet requires 6-8 times that amount.

When you eliminate or drastically restrict carbs, your body goes into ketosis, a metabolic state where your body burns fat for energy instead of glucose (which comes from carbs). Ketosis is also what your body does when it’s fasting or starving. The result of ketosis can be weight loss and improved insulin sensitivity.

However, previous research has shown that a low-carb, high-fat keto-like diet can lead to elevated LDL ("bad") cholesterol levels. Too much LDL is associated with atherosclerosis (a build-up of plaque in your coronary arteries), which is a known risk factor for heart disease.

In the latest study, researchers found that over a nearly 12-year period, people following a low-carb, high-fat keto-like diet had significantly higher levels of LDL cholesterol and twice the rate of experiencing a major cardiovascular event, including heart attacks, strokes, peripheral artery disease, and clogged heart arteries requiring stent surgery.

Who should avoid the keto diet?

Dr. Forrestal cautions that a keto diet isn’t right for everyone. If you already have heart disease or high cholesterol, a past history of heart events or surgery, an eating disorder, or are pregnant, a keto diet may not be safe for you.

How to do keto safely

If you are still thinking about starting a keto or keto-like diet, take the following steps to do so safely:

• Consult with your doctor or healthcare provider
• Know your family history with heart disease
• Address any additional risk factors you may already have, such as diabetes, high blood pressure, inactivity, poor sleep, and smoking
• Have your cholesterol levels monitored throughout
• Keep the duration short (this type of diet should not be a long-term diet)

Alternative heart-healthy diet options

Dr. Forrestal suggests a better-balanced, Mediterranean-style diet for heart health, focused on fresh vegetables and low-glycemic fruit, lean fish and white meat, whole grains, and a moderate amount of fat from sources like nuts and olive oil. Limiting sugar, salt, alcohol, red meat, and processed foods is also recommended.

The bottom line

While the newest research does not prove that a keto diet leads to heart disease, it does show a strong correlation between following a ketogenic or keto-like diet and developing heart disease.

It can cause nutrient deficiency

The ketogenic diet can cause nutrient deficiency. The diet restricts carbohydrates and replaces them with large amounts of healthy fats, which the body burns and turns into ketones for energy. This process is known as ketosis.

However, the food we eat influences how nutrients work in our body. Genetics, age, health conditions, medications, and metabolism also contribute to how well nutrients are absorbed in the body. Since the intake of certain foods is limited or eliminated on the keto diet, one may not get all the essential vitamins and minerals needed to maintain a healthy diet.

A keto diet may be lower in fiber because whole grains are eliminated, so constipation may occur. The diet may also increase the risk of ketoacidosis for those with type-2 diabetes and increase bad cholesterol.

Some common vitamin and mineral deficiencies on a keto diet include vitamin B1, vitamin B6, vitamin B7, vitamin B12, calcium, iron, magnesium, and phosphorus. These are all essential nutrients that the body needs to function properly.

To avoid nutrient deficiencies on a keto diet, it is recommended to eat high-quality meats like grass-fed beef, pastured pork, poultry, and eggs, which provide the necessary B vitamins, iron, and phosphorus. Dark, leafy greens, broccoli, and avocados are good sources of vitamin B2, B6, B7, calcium, and magnesium. Full-fat yogurt is a good source of vitamin B1, calcium, and phosphorus, while salmon, canned sardines, and some plant-based milks are good sources of calcium.

It may cause liver problems

The ketogenic diet is a high-fat, low-carb, moderate-protein diet. It can be beneficial for people with epilepsy, helping to reduce the frequency of seizures. It is also used as a weight-loss strategy, as it can reduce hunger and maintain higher metabolism rates than low-fat diets.

However, there are some risks associated with the keto diet. One of these is the potential to cause liver problems, including non-alcoholic fatty liver disease (NAFLD). NAFLD is a "silent killer", rarely showing early symptoms. It is caused by fat accumulation in the liver, which can lead to inflammation and dysfunction. The ketogenic diet can increase cholesterol accumulation in the liver, which may trigger more severe steatohepatitis and promote liver fibrosis progression.

In one case, a 57-year-old woman with obesity, binge eating disorder, and other mental health issues presented with worsened hyperlipidemia and elevated liver enzymes after starting a ketogenic diet. She discontinued the diet and her liver enzymes returned to normal within eight months, and her LDL-C levels normalized within a year.

Another case study found that a high-fat ketogenic diet increased cholesterol accumulation in the liver, which enhanced the severity of carbon tetrachloride (CCl4) and thioacetamide (TAA)-induced liver fibrosis in mice. The diet also caused more severe liver inflammation and reduced the liver's antioxidant and detoxification abilities.

Therefore, while the keto diet may offer some benefits, it is not without risks. It is important to be aware of the potential side effects and to monitor liver function and blood ketone, lipid, and enzyme levels if choosing to follow this diet.

It may cause kidney problems

The keto diet may cause kidney problems, especially for those who already have kidney disease. The diet's high protein content can lead to an increased risk of kidney damage.

The keto diet is defined as a high-fat, adequate-protein, and low-carbohydrate nutrition plan. It forces the body to burn fats and use alternative metabolic fuel by stimulating endogenous ketone production. The standard range of ketones in ketosis is up to 3.00 mmol/L, and anything beyond this level can result in serious medical conditions.

One of the most common and easily reversible consequences of the keto diet is kidney stones. Studies have shown that a high-protein diet can directly cause an increase in kidney volume and weight, resulting in the expansion of the mesangial matrix and tubulointerstitial fibrosis. Animal protein, in particular, has been linked to a higher incidence of kidney stones.

Additionally, the keto diet's high dietary acid load, caused by the consumption of high amounts of animal fat and protein, is associated with albuminuria (losing protein in urine) and the onset of chronic kidney disease. When you eat a high-protein diet, the kidney must work harder due to increased blood flow to the filtrating unit, which can lead to the progression of chronic kidney disease.

The keto diet can also potentially worsen metabolic acidosis, a common complication of chronic kidney disease, which ultimately affects bone and muscle health. Metabolic acidosis is caused by increased acid production from the diet.

Furthermore, those who already have chronic kidney disease may experience a further decline in kidney function due to the diet. Research has shown that a high-protein diet can lead to hyperfiltration and proteinuria in the early stages, eventually resulting in a loss of kidney function.

Therefore, while the keto diet may be effective for weight loss, it is important to consider the potential risks associated with it, especially for individuals with kidney disease or those at risk of developing it.

It may cause constipation

The keto diet is a low-carb, high-fat diet that can cause constipation. This is because the diet restricts foods that are rich in fibre, such as grains and legumes.

Constipation is a common issue for people on the keto diet. In fact, one person who followed the keto diet reported that they experienced "sometimes chronic constipation" while following the diet.

The keto diet restricts all bread, cereal and other grains, as well as most fruits and vegetables. These food groups are all rich sources of fibre, which is essential for healthy digestion and regular bowel movements.

Fibre helps to add bulk to stool, making it easier to pass. It also helps to feed the beneficial bacteria in the gut, which are important for digestive health.

By restricting these food groups, the keto diet can make it difficult to get enough fibre, leading to constipation.

To avoid constipation on the keto diet, it is important to include plenty of fibre-rich foods. Although the diet restricts many high-fibre foods, there are still some options available.

Some keto-friendly foods that are good sources of fibre include:

• Leafy greens, such as kale, spinach and Swiss chard
• Cauliflower, broccoli, Brussels sprouts, asparagus, bell peppers, onions, garlic, mushrooms, cucumber and summer squashes
• Nuts, such as almonds and walnuts
• Seeds
• Avocados
• Tofu

In addition to including these fibre-rich foods, it is also important to stay properly hydrated by drinking enough water. This can help to prevent constipation, as adequate fluid intake is necessary for healthy digestion and regular bowel movements.

If you are experiencing constipation on the keto diet, it is important to address the issue. Constipation can be uncomfortable and may lead to other health issues if left untreated.

If you are unable to relieve constipation by increasing your fibre intake and water consumption, it may be necessary to make further adjustments to your diet or speak to a healthcare professional.

Frequently asked questions