Keto flu explained: What really happens to your body on the keto diet |
The ketogenic diet, or keto diet, has gained global attention for its promise of quick weight loss and better blood sugar control. By eating fewer carbohydrates and increasing fat intake, the body is pushed into a state called ketosis, where fat becomes the main source of energy. While the diet often leads to rapid results in the short term, experts are beginning to question its long-term effects. A recent study published in Science Advances has revealed new insights into the health risks linked to extended keto use. The research shows that, beyond early weight loss, the diet may trigger several metabolic and organ-related challenges, particularly highlighting the phenomenon commonly known as the “keto flu.”
Keto flu symptoms: Why fatigue, dizziness, and nausea strike early
For many, starting the keto diet feels like a shock to the system. During the first few days or weeks, it is common to experience symptoms known as the “keto flu.” These include headaches, nausea, fatigue, irritability, and dizziness. The body, which is used to running on carbohydrates, suddenly has to adapt to burning fat for fuel. This major metabolic shift can lead to short-term side effects as the body adjusts to its new energy source.As carbohydrates are cut down drastically, the body loses water and electrolytes such as sodium, potassium, and magnesium. This results in dehydration, muscle cramps, and tiredness. People often describe this phase as the hardest part of keto, both physically and mentally. Though temporary, these symptoms serve as a reminder that such drastic dietary changes come with physiological consequences.To make this transition safer, experts suggest taking it slow, reducing carbohydrate intake gradually instead of all at once. Drinking plenty of fluids and consuming foods rich in minerals like leafy greens, avocados, and nuts can help restore electrolyte balance and reduce the severity of symptoms.
Keto and kidneys: How the diet may increase stone formation
The report also warns of potential kidney complications linked to a high-fat, low-carb eating pattern. Since the keto diet relies heavily on animal fats and proteins, it raises the acid levels in the body. This forces the kidneys to work harder to maintain pH balance, often leading to increased calcium in the urine. Over time, this condition can contribute to the formation of kidney stones.The kidneys play a crucial role in removing waste and regulating mineral levels, and when overburdened, they may not function as efficiently. For people who already have kidney-related issues, this added strain could be particularly dangerous.Healthcare professionals advise anyone considering the keto diet, especially those with a history of kidney stones or pre-existing kidney conditions to undergo regular health check-ups. Monitoring urine and blood parameters can help identify early warning signs before they develop into more serious complications.
Keto diet digestion: Constipation, nutrient loss, and gut imbalance
Beyond kidney health, another challenge of the keto diet lies in digestion. The strict limitation on carbohydrate foods such as fruits, grains, and starchy vegetables often leads to a sharp decline in fibre intake. Fibre is essential for maintaining healthy digestion, supporting gut bacteria, and preventing constipation.Without enough fibre, many people experience bloating, sluggish digestion, and irregular bowel movements. The report also points to long-term nutrient deficiencies associated with keto, including vitamins A, C, and several B-complex vitamins. These deficiencies can affect immunity, skin health, and overall energy levels.Nutritionists recommend including fibre-rich, low-carb vegetables such as spinach, broccoli, cauliflower, and zucchini in daily meals. In some cases, supplements may be necessary to replace the missing nutrients. By planning meals carefully and ensuring a variety of foods within the keto framework, followers can reduce some of the digestive side effects while maintaining nutritional balance.
Metabolic changes and long-term risks of keto diet
The research goes beyond short-term symptoms and reveals that remaining on keto for extended periods can disrupt normal metabolism. It states, “These results suggest that long-term KD leads to multiple aberrations of metabolic parameters that caution their systematic use as a health-promoting dietary intervention.”This suggests that while keto may help some individuals initially, prolonged adherence could interfere with healthy blood fat and glucose regulation. Over time, this may raise the risk of metabolic irregularities or cardiovascular issues.Another challenge the study highlights is the difficulty of maintaining strict ketosis. Many people eventually reintroduce carbohydrates after months on keto, which can confuse the body’s metabolism. The report explains, “As most people who go on a KD will likely consume glucose eventually due to the difficulty to strictly adhere to a KD long term, this is of critical importance for patients using a KD to treat obesity and related metabolic conditions such as type 2 diabetes.”This statement underscores a vital point—those using keto for medical reasons, such as managing obesity or type 2 diabetes, should make any dietary changes under medical supervision. Abruptly returning to a high-carb diet can cause fluctuations in blood sugar and energy levels, which may be harmful in the long run.Keto flu may only last a few weeks, but it serves as an early signal of the body’s struggle to adapt to a diet that drastically alters its natural balance. While the keto diet can bring short-term benefits, its effects on hydration, digestion, and long-term metabolism suggest that it should be approached carefully and ideally under professional guidance. Balancing the promise of quick results with the need for sustainable health remains the key to making informed dietary choices.Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult a healthcare professional before making any changes to your diet, medication, or lifestyle.Also Read | Multigrain Atta vs Whole Wheat Atta: Choosing the healthiest flour for your diet and optimal health
