Keto Diet Safety:The Truth About Keto's Potential Risks and Long-Term Effects

The keto diet, short for ketogenic diet, is a high-fat, adequate-protein, low-carbohydrate eating pattern. It aims to shift the body's energy metabolism from glucose (derived from carbohydrates) to ketones, which are produced when the body burns fat for fuel. This metabolic state is called ketosis.

By severely restricting carbohydrate intake, typically to less than 50 grams per day, the body is forced to rely on fat for energy instead of glucose. This includes burning stored body fat, which leads to weight loss, one of the primary goals for many people adopting the keto diet.

When you eat a high-carb meal, your body produces glucose and insulin. Glucose is the easiest molecule for your body to convert to energy, so it will be chosen over any other energy source. As a result, the fats we eat are not needed and are therefore stored. Insulin, produced to process the glucose in our bloodstream, facilitates this storage of fat in our cells.

On a keto diet, by reducing carbohydrate consumption, and thereby lowering insulin levels, the body is induced into a state where it burns fat for energy instead of glucose. This is the fundamental principle of ketosis, and it leads to two primary outcomes: increased fat burning and reduced hunger.

The standard ketogenic diet (SKD) typically includes the following ratios of macronutrients:

It's important to note that not all fat sources are equal. The type of fat consumed is crucial. Emphasizing healthy, whole-food sources of fat is essential, as processed and refined fats can have negative health impacts.

Additionally, staying well-hydrated and ensuring adequate electrolyte intake is vital on the keto diet, as the initial shift to ketosis can cause fluid and mineral imbalances, leading to what is commonly known as the "keto flu."

When your body enters ketosis, it becomes extremely efficient at burning fat for energy. The liver produces ketone bodies from fat, providing energy for the brain and body. This metabolic state can have various effects on the body and brain, including reduced hunger, increased mental clarity, and improved energy levels.

Ketosis is the cornerstone of the keto diet, and understanding how to achieve and maintain this state is critical to the diet's success and safety.

Interestingly, the keto diet wasn't originally designed as a weight-loss strategy. Its origins lie in the treatment of drug-resistant epilepsy, particularly in children. The diet was developed in the 1920s as a way to mimic the effects of fasting, which was shown to reduce seizure activity.

Today, the keto diet has evolved to become a popular weight-loss and health-improvement strategy, with numerous testimonials and research studies supporting its effectiveness.

One of the most well-known and researched benefits of the keto diet is its effectiveness for weight loss. By reducing carbohydrate intake, the body shifts to burning fat for energy, including stored body fat. This can lead to significant weight loss, particularly in the initial phases of the diet.

Additionally, the keto diet has been shown to preserve muscle mass during weight loss, leading to improved body composition. This is partly due to the adequate protein intake recommended on the keto diet, which helps maintain muscle tissue while still promoting fat burning.

Ketosis provides the brain with a consistent energy source in the form of ketone bodies. This can lead to increased mental clarity, improved focus, and enhanced cognitive function. The stable energy levels provided by ketones may also contribute to a reduced "brain fog" feeling and improved overall productivity.

The keto diet's low-carb nature can lead to improved insulin sensitivity and better blood sugar control. This is especially beneficial for individuals with type 2 diabetes or prediabetes, as it can help stabilize blood glucose levels and reduce the reliance on medication.

The keto diet has been shown to reduce cravings, particularly for sugar and carbohydrates. This can lead to improved eating habits and a healthier relationship with food. The high-fat, moderate-protein nature of the diet promotes satiety, helping individuals feel fuller for longer and reducing the urge to snack between meals.

Beyond weight loss, the keto diet has been studied for its potential neuroprotective benefits. It has been used therapeutically for conditions like epilepsy, and there is ongoing research into its potential benefits for Alzheimer's disease, Parkinson's disease, and other neurological disorders.[5]

Despite its high-fat nature, the keto diet has been associated with improved heart health markers. This includes increased HDL ("good") cholesterol levels, reduced blood triglycerides, and improved blood pressure. However, it's important to note that more long-term studies are needed to fully understand the impact of keto on cardiovascular health. [5]

One of the most common short-term side effects of the keto diet is often referred to as the "keto flu." This feeling of fatigue, brain fog, headaches, nausea, and irritability can occur during the first few days or weeks of starting the diet. It is caused by the body's transition from using glucose to ketones as its primary energy source.

During this metabolic shift, fluid and mineral imbalances can occur, leading to symptoms similar to the influenza virus. However, these side effects are usually temporary and can be mitigated by ensuring adequate hydration, increasing electrolyte intake, and getting enough rest.

Digestive problems, such as constipation or diarrhea, are also common during the initial stages of keto. These issues often arise due to the reduction in carbohydrate intake, as carbohydrates can have a hydrating effect on the gut. Ensuring adequate fluid intake and consuming plenty of fibrous low-carb vegetables can help alleviate these issues.

Strategies for Mitigation

To minimize the impact of these short-term side effects:

By being aware of these potential challenges and taking proactive measures, individuals can better manage the short-term side effects of the keto diet and set themselves up for long-term success.

The keto diet's impact on heart health is a highly debated topic. Conflicting evidence and research exist, leaving individuals wondering about the potential risks. Some studies suggest that low-carb diets, like keto, that prioritize animal-based foods may increase the risk of heart disease and other adverse health outcomes.[1] This is proposed to be linked to the typically high saturated fat intake associated with these diets.

However, a study published in the NCBI contradicts this notion.[2] It found that obese patients following a long-term ketogenic diet experienced significant improvements in heart health markers, including reductions in body weight, BMI, triglycerides, and LDL ("bad") cholesterol. These findings indicate a potential benefit of the keto diet for those struggling with obesity and related cardiovascular risk factors.

Adding to the complexity, a comprehensive review published in Frontiers in Nutrition linked the keto diet to an increased risk of heart disease and LDL cholesterol buildup. [3] This review analyzed over 100 peer-reviewed studies on keto diets and their long-term effects, suggesting that the negative consequences may outweigh any short-term benefits.

The conflicting evidence underscores the need for more comprehensive, long-term studies specifically examining the impact of keto on heart health. As of now, the jury is still out on whether the keto diet is a friend or foe when it comes to cardiovascular wellness.

The high protein content of the keto diet, especially from animal sources, has raised concerns about its impact on kidney health. [1] On one hand, the increased intake of animal proteins can lead to higher levels of acid in the blood and urine, which can cause kidney stones and worsen existing kidney conditions. This is a particular concern for individuals with chronic kidney disease (CKD), as the high protein intake on keto can further stress their kidneys.

However, it's important to note that not all kidney-related concerns are universal. Some studies suggest that a well-formulated keto diet may even improve kidney function in those with mild kidney issues. Additionally, the NCBI study mentioned earlier found no adverse effects on kidney function in obese patients following a long-term ketogenic diet. [2]

The potential impact of the keto diet on bone health is another area of concern. Animal studies and research in children with epilepsy have indicated a decrease in bone mineral density and strength when following a keto diet.[1] This could potentially lead to an increased risk of fractures and other bone-related issues over time.

However, it's worth noting that these studies were not specifically designed to examine the long-term effects of keto on bone health, and more direct research is needed. Ensuring adequate nutrient intake, particularly calcium and vitamin D, and engaging in weight-bearing exercises may help mitigate these risks.

The relationship between the keto diet and cancer risk is complex. On one hand, the diet's focus on reducing sugar intake and stabilizing blood sugar levels may positively impact cancer risk, as elevated glucose and insulin levels are linked to cancer growth. [2]

However, the potential link between high-fat diets and cancer development cannot be ignored. Some studies suggest that very high-fat diets, especially those rich in animal fats, may promote tumor growth, particularly in individuals with a genetic predisposition to certain cancers. [3] More extensive research is needed to fully understand this complex relationship.

Additionally, the keto diet has been studied for its neuroprotective effects, showing benefits in managing epilepsy and potentially stabilizing mood in bipolar illness. [2] However, the Frontiers in Nutrition review linked the diet to an increased risk of Alzheimer's disease, highlighting the need for further investigation into the long-term neurological impacts of keto. [3]

The restrictive nature of the keto diet may lead to nutrient deficiencies over time if not properly managed. [1] Excluding certain food groups can result in inadequate intake of essential vitamins and minerals, such as calcium, magnesium, and vitamin D. Ensuring a varied intake of keto-friendly whole foods and considering targeted supplementation can help prevent these deficiencies.

The Frontiers in Nutrition review also raised concerns about the overall safety of the keto diet, linking it to an increased risk of diabetes, kidney failure, and Alzheimer's disease, in addition to the previously mentioned health issues. [3] It's important to note that this review analyzed the diet's long-term effects, suggesting that the negative consequences may far outweigh any short-term benefits.

The success of the keto diet relies heavily on understanding and maintaining the correct macronutrient ratios. These ratios guide your food choices and ensure you're getting the right balance of fats, proteins, and carbohydrates to achieve and maintain ketosis.

Emphasizing whole, unprocessed foods is crucial on the keto diet. Not only do whole foods provide a richer source of nutrients, but they also offer protective benefits against various health conditions.

The restrictive nature of the keto diet may lead to nutrient deficiencies if not properly managed. Certain nutrients commonly found in carbohydrate-rich foods, like some B vitamins and minerals, may be lacking.

Pregnancy and breastfeeding are critical periods for maternal and child health, and the keto diet may pose unnecessary risks during these times. A review in Frontiers in Nutrition found that keto diets can be particularly dangerous for pregnant women, potentially leading to birth defects and gestational diabetes. [4] The diet's high-fat content and potential for nutritional deficiencies could impact fetal development and maternal health.

Additionally, the keto diet may impair lactation performance and breast milk composition, potentially affecting infant health and growth. Therefore, it is generally recommended that pregnant and breastfeeding women avoid restrictive diets like keto and instead focus on a well-rounded, nutrient-dense diet to support their changing bodies and the needs of their growing child.

The keto diet's high protein content, especially from animal sources, can be concerning for those with kidney disease. [1] The increased acid load from these foods can worsen chronic kidney disease (CKD) and lead to a dangerous condition called acidosis. Individuals with kidney issues should consult with their healthcare provider before considering the keto diet, as it may further stress their kidneys and accelerate disease progression.

While the keto diet has been proposed as a potential treatment for type 2 diabetes, it should be approached with caution in this population. Some evidence suggests that low-carb diets focused on animal foods may increase the risk of heart disease and all-cause mortality compared to plant-based low-carb diets. [1] Those with existing heart conditions or diabetes should consult their healthcare provider before starting keto, as they may need more specialized guidance and monitoring.

Additionally, the high-fat content of the keto diet, if not properly managed, could potentially impact blood lipid profiles and further increase cardiovascular risk factors. Therefore, it is crucial for individuals with diabetes or heart disease to seek expert medical advice and carefully consider the potential benefits and risks of adopting the keto diet.

The keto diet's restrictive nature may exacerbate existing nutrient deficiencies or create new ones. [1] If an individual already struggles with inadequate intake of certain vitamins, minerals, or fiber, the keto diet's exclusion of carbohydrate-rich foods could further limit their nutrient sources.

Those with a history of eating disorders or disordered eating patterns may also find the restrictive nature of the keto diet triggering. It is crucial to prioritize overall health and well-being and consult a healthcare professional to address any underlying nutritional deficiencies or disordered eating behaviors before considering the keto diet.

The keto diet may not be suitable for individuals with specific medical conditions, especially those that require careful management of nutrient intake. For example, individuals with pancreatic, liver, or gallbladder issues should approach keto with caution, as the high-fat content may exacerbate these conditions.

Additionally, those with a history of kidney stones should be aware that the keto diet's impact on urine acidity could increase the risk of kidney stone formation. The diet's restriction of certain vegetables and fruits may also be concerning for individuals with a history of gout or those prone to inflammatory conditions.

Growing children and adolescents have unique nutritional needs to support their development, and the keto diet may not adequately meet these requirements. The diet's restriction of carbohydrate-rich foods could impact their energy levels and cognitive function. [4] Additionally, the potential impact on bone health could be concerning during critical growth periods.

It is generally recommended that children and adolescents focus on a well-rounded, nutrient-dense diet that includes a variety of whole grains, fruits, vegetables, lean proteins, and healthy fats to support their growth and development optimally.

The keto diet, with its unique approach to macronutrient ratios, has gained popularity for its weight-loss and health benefits. However, as we've explored throughout this article, it is not without its potential risks and considerations. Understanding these is crucial for making an informed decision about your health and wellness journey.

The keto diet can be a powerful tool for those seeking to lose weight and improve certain health markers, but it is not a casual dietary shift. It requires commitment, planning, and a good understanding of the underlying principles to ensure safety and effectiveness.

We've delved into the potential benefits, including weight loss, improved body composition, enhanced energy levels, and better blood sugar control. However, we've also explored the short-term side effects, such as the "keto flu," digestive issues, and reduced physical performance. These challenges often occur during the initial transition phase and typically resolve within a few weeks.

More importantly, we've addressed the long-term health concerns, including the impact on heart health, kidney function, bone health, and cancer risk. While some of these concerns are valid, much of the negativity surrounding keto is based on misconceptions or a lack of understanding. Proper planning, nutrient tracking, and working with a healthcare professional can help mitigate many of these risks.

Lastly, we've discussed who should approach keto with caution or avoid it altogether. The keto diet may not be suitable for everyone, and certain individuals, such as those with specific medical conditions, pregnant or breastfeeding women, and children, should consult a healthcare provider before considering keto.

As you reflect on the insights provided in this article, remember that your health is a journey unique to you. Always prioritize your overall well-being and seek personalized guidance when needed.

Do you plan on starting the keto diet, or have you ever experienced any side effects from it? If so, what was your experience, and how did you manage it?

1. Adams, K. (2023). Dangers of the keto diet: 9 serious keto diet dangers and side effects. Healthline. https://www.healthline.com/nutrition/dangers-of-keto-diet

2. Freeman, J. M., Kossoff, E. H., & Hartman, A. L. (2007). The ketogenic diet: one decade later. Pediatrics, 119(3), 535-543. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/

3. New Study Links Keto Diet to Severe Long-Term Health Risks. (2022). Forks Over Knives. https://www.forksoverknives.com/wellness/new-study-links-keto-diet-to-severe-long-term-health-risks/

4. List of foods to avoid on keto. (n.d.). Well Versed. https://wellversed.in/blogs/articles/list-of-foods-to-avoid-on-keto

5. Kossoff, E. H., Zupec-Kania, B. A., Amark, P. E., & Rohde, C. (2020). Ketogenic diets: an update for child neurologists. Neurologic Clinics, 38(3), 695-709. https://www.ncbi.nlm.nih.gov/books/NBK499830/