The ketogenic diet, commonly known as keto, works by forcing the body into a state of ketosis, where it burns fat for energy instead of glucose from carbohydrates. This metabolic shift, however, is not without its drawbacks. Both immediate and long-term negative effects are reported, prompting caution and consultation with a healthcare provider before adoption.
The Short-Term Downsides: Navigating the 'Keto Flu'
Many people transitioning to a keto diet experience a collection of symptoms often called the "keto flu". This occurs as the body adapts to burning fat for fuel instead of glucose. While typically temporary, these side effects can be unpleasant and discouraging.
- Fatigue and Brain Fog: The body is used to a readily available supply of glucose for energy. The shift to ketones can lead to feelings of lethargy and difficulty concentrating.
- Headaches and Irritability: These are common withdrawal-like symptoms experienced during the initial phase.
- Digestive Issues: Both constipation and diarrhea can occur. The lack of fiber from restricted grains, fruits, and starchy vegetables is often to blame for constipation, while the sudden increase in fat intake can cause diarrhea for some.
- Bad Breath: As the body produces ketones, a by-product called acetone is released, which can give breath a fruity, nail-polish-remover-like smell.
- Muscle Cramps: A loss of electrolytes, such as sodium, magnesium, and potassium, through increased urination during the initial phase can lead to muscle cramping.
The Long-Term Health Risks
While short-term side effects usually subside, adhering to a ketogenic diet for an extended period can pose more serious health risks that are still being studied.
Cardiovascular Concerns
Studies have shown that low-carbohydrate, high-fat (LCHF) diets, similar to keto, are associated with potential heart problems. A major concern is the increase in low-density lipoprotein (LDL) cholesterol, often called "bad" cholesterol, which can heighten the risk of cardiovascular disease. A recent study noted a twofold heightened risk of cardiovascular events, such as heart attack and stroke, among those on a keto-like diet.
Kidney and Liver Health
High-protein intake, which sometimes accompanies high-fat intake on keto, can be stressful for the kidneys. In some cases, this can lead to the formation of kidney stones. For individuals with pre-existing kidney conditions, the diet could exacerbate problems. Liver dysfunction, including the accumulation of fat in the liver, has also been noted in long-term studies on mice.
Nutritional Deficiencies
By restricting fruits, whole grains, and starchy vegetables, the keto diet limits the intake of vital fiber, vitamins, and minerals. This can lead to nutrient deficiencies that may impact bone health and overall immunity.
The Impact on Social Life and Sustainability
Adhering to the strict dietary rules of keto is difficult for many, making it unsustainable long-term. The rigid nature can lead to social isolation when dining out or attending social events. The all-or-nothing approach can also contribute to unhealthy yo-yo dieting patterns, where weight is lost and then regained, potentially with negative metabolic consequences. For more information on the diet's sustainability, read this article by Northwestern Medicine.
Keto vs. Mediterranean Diet: A Comparison of Health Implications
| Feature | Ketogenic Diet | Mediterranean Diet |
|---|---|---|
| Macronutrient Focus | Very low carbohydrates, very high fat, moderate protein. | High in whole foods, complex carbs, healthy fats, and moderate protein. |
| Food Restrictions | Highly restrictive, eliminates fruits, grains, legumes, and many vegetables. | Inclusive of a wide variety of plant-based foods, healthy fats, and lean protein. |
| Cardiovascular Risk | Potential for increased LDL ("bad") cholesterol and heart event risk. | Associated with lower risk of heart disease and improved cardiovascular health. |
| Sustainability | Difficult for most to sustain long-term due to strict rules. | Generally considered a sustainable, long-term lifestyle change. |
| Nutrient Density | High risk of nutrient deficiencies without careful planning or supplementation. | Rich in fiber, vitamins, and minerals from a diverse range of whole foods. |
Conclusion: Weighing the Risks and Benefits
While the ketogenic diet can be effective for short-term weight loss, particularly as a medically supervised therapy for conditions like epilepsy, its cons are considerable. The initial transition can be rough, and long-term adherence carries risks to cardiovascular, kidney, and liver health. The restrictive nature of the diet makes it challenging to sustain and may lead to nutritional deficiencies and unhealthy eating patterns. Before embarking on a keto diet, a person should thoroughly research the risks, consult a healthcare professional, and consider whether a less restrictive, more balanced eating pattern like the Mediterranean diet might be a more sustainable option for long-term health.
