Keto Diet: Healthy Long-Term Weight Loss Solution?

The ketogenic or keto diet is a low-carb, high-fat, moderate-protein eating plan that has become increasingly popular. It involves reducing total carbohydrate intake to less than 50 grams per day, with some people consuming less than 20 grams per day. The goal is to induce weight loss by forcing the body to burn fat for energy instead of carbohydrates. While keto can lead to initial weight loss, there are concerns about its long-term health effects.

The keto diet is associated with several potential risks. Firstly, it can lead to vitamin and mineral deficiencies, as it often involves reducing or eliminating fruits, vegetables, whole grains, and legumes. This can result in deficiencies in essential nutrients such as thiamin, folate, vitamin A, vitamin E, vitamin B6, calcium, magnesium, iron, and potassium. Additionally, keto diets are typically low in fiber, which is important for digestive health and nutrient absorption.

Another concern is the impact of keto on athletic performance. Some research suggests that keto may sabotage strength and fitness, as the body is in a more acidic state during ketosis, which may limit its ability to perform at peak levels.

Keto can also affect blood vessels. Indulging in high-sugar treats while on a keto diet can damage blood vessels, and there is evidence that long-term keto may increase the risk of cardiovascular disease and other negative cardiac events.

Furthermore, keto may not be suitable for everyone. For example, pregnant or planning-to-be pregnant individuals should avoid keto as it has been linked to an increased risk of birth defects.

While some people may find benefits in keto, such as weight loss and improved mental clarity, it is important to consider the potential risks and consult a healthcare professional before starting any new diet.

Keto may lead to vitamin or mineral deficiencies

The keto diet is a high-fat, low-carb, and moderate-protein eating plan that has gained popularity in recent years. While it has been advertised as a weight-loss solution, it is actually a medical diet that carries serious risks and should not be attempted without consulting a doctor and a registered dietitian.

One of the risks of the keto diet is the potential for vitamin and mineral deficiencies. This is because many vitamin- and mineral-rich foods like fruits, vegetables, grains, and legumes are restricted on the keto diet.

Micronutrient Deficiencies

Vitamins and minerals, also known as micronutrients, are essential for the body's daily functions, even though they are only needed in small amounts. A balanced diet full of whole foods typically provides adequate amounts of most micronutrients.

However, the keto diet's restriction of carbohydrates and its effects on how the body processes nutrients can lead to deficiencies. Studies have found that the keto diet provides sub-optimal levels of many micronutrients.

The classic keto diet, which is high in fat and restricts carbohydrates and protein, can lead to a disturbance in the balance of micronutrients due to increased excretion and lowered consumption of micronutrient-rich foods.

Specific Vitamin and Mineral Deficiencies

Calcium

People on long-term keto diets may lose too much calcium through their urine, and their urine may become more acidic. High-fat diets can increase acid production in the body, which the kidneys must filter out to maintain stable blood pH. This can lead to lower urine pH and the use of calcium from bones to buffer the increased acid production, resulting in higher calcium loss and lower bone density.

Magnesium

Magnesium is another mineral that has been observed to decrease on a long-term keto diet. This mineral is crucial for energy production and the proper functioning of nerve cells and the brain. Deficiency has been linked to various conditions, including heart disease and migraines. Symptoms of magnesium deficiency include muscle cramps, headaches, anxiety, nervousness, and constipation.

Iron

Even though keto diets usually involve eating ample quantities of meat, they can also lead to reduced iron levels. Iron is necessary for energy production and the formation of red blood cells, and its deficiency can cause fatigue and trouble breathing during exercise. Evidence suggests that the high amounts of fat in the keto diet may reduce iron absorption.

Selenium

Selenium is a mineral that plays important roles in heart health, reproduction, thyroid hormone production, and protecting the body from oxidative stress. Research and clinical experience have found that the keto diet can decrease selenium levels and lead to deficiencies in the long run. High-fat foods tend to be low in selenium.

Biotin (Vitamin B7)

Biotin, also known as vitamin B7, is necessary for maintaining healthy hair, skin, and nails. It is naturally found in keto-friendly foods like liver, egg yolks, meat, salmon, avocados, and cauliflower. However, biotin is used up extensively when the body is processing fatty acids while on the keto diet, and deficiency can occur.

Other Micronutrients

Other micronutrients that may be deficient on the keto diet include folate (B9), vitamins A, D, and E, chromium, iodine, and molybdenum.

Preventing Deficiencies

To prevent vitamin and mineral deficiencies on the keto diet, it is important to include a variety of nutrient-dense foods, such as grass-fed meat, poultry, wild-caught fish, liver, spinach, kale, nuts, and seeds.

Supplementation with specific vitamins and minerals or a focus on vitamin-rich foods is recommended. Working with a doctor to monitor nutrient levels and make any necessary adjustments is crucial.

It may affect athletic performance

The keto diet has been a topic of interest for athletes, with some adopting it to boost their endurance performance. However, there is conflicting evidence regarding its effectiveness, and some researchers worry about its potential negative impact on athletic performance.

Evidence and concerns

A 2019 study found that participants performed worse on high-intensity cycling and running tasks after spending four days on a ketogenic diet compared to a high-carb diet. The body is in a more acidic state when in ketosis, which may limit its ability to perform at peak levels.

Additionally, the keto diet may affect an athlete's strength and fitness. While it can help with weight loss, which is beneficial for speed and endurance, researchers caution that the benefits of weight loss could be cancelled out by reductions in performance.

Practical recommendations

• The keto diet may be suitable during periods of low-intensity, base training, such as the build-up phase at the start of the season.
• Expect to feel more fatigued during exercise when switching to a keto diet, even if the training intensity is low.
• It is not recommended to experiment with a keto diet during periods of higher-intensity training, which relies on adequate muscle carbohydrate (glycogen).
• For races under three hours, continuing a keto diet is not advised, as most evidence suggests it will harm maximum performance.
• If a race is approaching, it is recommended to switch to a high-carb diet 24-36 hours beforehand and consume carbohydrates during the race.
• Be aware that individuals can respond very differently to a keto diet. Some may experience severe side effects like poor energy and mental function, sleep issues, and nausea, while others may adapt more easily.

Relaxing the rules can cause weight regain

The keto diet is notoriously strict, and it can be difficult to adhere to its guidelines for an extended period of time. Many people relax the rules after the first stage of the diet, which usually lasts one to three months. This relaxation often takes the form of "lazy keto", "keto cycling", or "maintenance mode", where more carbohydrates are allowed or there is less monitoring of food intake. However, this relaxation of the rules can lead to weight regain. Annette Frain, RD, program director with the Weight Management Center at Wake Forest Baptist Health, notes that "keto can be a great jump-start to weight loss, but the reality is that most people can't adhere to it for very long".

People often lose weight during the initial stage of the keto diet, but this weight is often regained once they come out of ketosis. This can lead to a yo-yo pattern of weight loss and weight gain, which is extremely frustrating and is linked to a higher risk of early death. Furthermore, the type of weight that is regained is important. When people first start the keto diet, they often lose muscle mass along with fat tissue. When they come out of ketosis and start following a high-fat diet, they will probably gain back more fat and less lean muscle. This can affect their metabolism and make it more difficult to lose weight in the future, as fat burns calories at a slower rate than muscle.

Therefore, while the keto diet can be an effective way to lose weight in the short term, it is important to be aware of the potential risks of weight regain if the rules of the diet are relaxed.

It may damage blood vessels

The ketogenic diet is advertised as a weight-loss wonder, but it is actually a medical diet that comes with serious risks. One of the top risks is that the keto diet may damage blood vessels.

The keto diet is high in saturated fat, which is linked to an increased risk of heart disease. Research shows that a diet rich in animal fats and proteins may negatively impact heart health. The diet's heavy reliance on fat, especially saturated fat, can raise cholesterol levels, further increasing the chances of developing heart disease in the future.

Some studies have found that low-carb and very-low-carb plans (which keto fits into) have mixed effects on blood cholesterol levels, with some studies finding that these diets raise cholesterol. A 2019 study from the University of British Columbia found that indulging in a high-sugar treat while on a high-fat, low-carb diet can damage blood vessels. The study suggested that the ketogenic diet should not be something that is followed for only six days a week and then taken a break from, as this could undo some of the positive impacts on blood vessels.

Two similar studies from 2014, one from Sweden and one from Italy, found that patients on ketogenic diets may have early signs of blood vessel injury as evident by less distensibility on ultrasound. The walls of the blood vessels did not seem to get thicker, but something in the diet may be having an effect. The Swedish study found that after 12 months of diet use, or after the diet was stopped (in the Italian study), these changes seemed to revert back to normal. Neither study reported any clinical changes in the children, and none had any described cardiac symptoms.

However, more studies are needed to fully understand the long-term effects of the keto diet on blood vessels.

It may increase the risk of heart disease

The ketogenic diet is associated with an increased risk of heart disease. The diet is high in saturated fat, which is linked to heart disease. The diet is also associated with an increase in "bad" LDL cholesterol, which is also linked to heart disease.

A 2019 study published in the Journal of the American College of Cardiology found that people on low-carb diets are more likely to develop atrial fibrillation, which raises the risk of blood clots, stroke, and heart failure. Research published in The Lancet in 2018 found that low-carb dieters who consumed large amounts of meat and dairy had a higher risk of early death compared to those who consumed carbs in moderation or who consumed mostly plant-based protein.

A 2023 study presented at the American College of Cardiology's Annual Scientific Session found that a "keto-like" diet may be associated with higher blood levels of "bad" cholesterol and a twofold heightened risk of cardiovascular events such as chest pain, blocked arteries requiring stenting, heart attacks, and strokes.

A 2023 study in the Journal of Clinical Medicine found that a ketogenic diet may be a more effective option for long-term weight loss and improvements in some heart disease risk factors compared to low-fat diets. However, it is important to note that there is still a lot that health experts don't know about the long-term effects of the keto diet, and some warn that it could be dangerous.

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