The ketogenic diet has become increasingly popular across Australia as a way to lose weight, boost energy, and improve health. However, like any significant dietary change, keto can come with side effects-especially during the initial adjustment period. Understanding these potential effects can help you prepare and manage them effectively for a smoother transition.
Common Short-Term Side Effects: The “Keto Flu”
Many Australians starting keto experience a group of symptoms often called the “keto flu.” These usually appear within the first few days to weeks as your body adapts to burning fat instead of carbohydrates. Typical symptoms include:
- Fatigue and weakness
- Headaches and dizziness
- Nausea and digestive discomfort
- Constipation due to lower fibre intake
- Bad breath (sometimes fruity or metallic, known as “keto breath”)
- Irritability, low mood, and brain fog
- Difficulty sleeping or “keto insomnia”
These symptoms are linked to changes in metabolism, dehydration, and electrolyte imbalances caused by reduced carbohydrate intake and glycogen depletion. Staying well-hydrated and replenishing electrolytes with salt, magnesium, and potassium can help ease these effects.
Digestive Issues
Because keto restricts many high-fibre foods like grains and some fruits, constipation and gastrointestinal discomfort are common complaints. Some people also experience diarrhea or bloating as their gut adjusts to the new diet. Including low-carb, fibre-rich vegetables such as leafy greens and cruciferous veggies, and drinking plenty of water can support digestive health.
Potential Long-Term Side Effects
While short-term side effects usually resolve within weeks, some concerns exist about the longer-term impact of keto, especially if not carefully managed:
- Kidney Stones: High fat and protein intake, along with dehydration, can increase the risk of kidney stones.
- Fatty Liver: Some evidence suggests a risk of hepatic steatosis (fatty liver) with prolonged keto diets.
- Nutrient Deficiencies: Restrictive eating patterns can lead to inadequate intake of vitamins, minerals, and phytochemicals if variety is limited.
- Heart Health Risks: High saturated fat intake and low fibre may negatively affect cholesterol and cardiovascular health in some individuals.
- Muscle Loss: Rapid weight loss without adequate protein and exercise may cause muscle mass reduction.
- Increased Risk of Atrial Fibrillation: Some research links low-carb diets to heart rhythm disorders, though evidence is still emerging.
Who Should Be Cautious?
Certain groups should approach keto with extra care or avoid it altogether unless supervised by a healthcare professional:
- People with pancreatitis, liver failure, or fat metabolism disorders
- Individuals with kidney disease
- Those taking medications for diabetes (especially insulin or SGLT2 inhibitors) due to risk of hypoglycemia or diabetic ketoacidosis
- Pregnant or breastfeeding women
- Anyone with a history of eating disorders or nutrient deficiencies
How to Minimise Side Effects on Keto in Australia
- Hydrate well: Drink plenty of water and consider electrolyte supplements.
- Eat a variety of low-carb vegetables: To boost fibre and micronutrient intake.
- Start gradually: Slowly reduce carbs instead of an abrupt cut to ease adaptation.
- Monitor your health: Regular check-ups with your GP or dietitian can help catch any issues early.
- Listen to your body: If symptoms persist or worsen, reassess your diet or seek professional advice.
The ketogenic diet can offer many benefits, but it’s important to be aware of and prepared for possible side effects, especially in the early stages. Most short-term symptoms resolve with time and proper care, but long-term effects require mindful planning and medical oversight. Australians considering keto should consult healthcare professionals to ensure the diet is safe and suitable for their individual health needs.