🥑 Ketogenic Diet: Complete Guide to the Metabolism-Transforming Eating Strategy
Everything You Need to Know About Ketosis, Fat, Sugar, and Metabolic Health
🔍 What is the ketogenic diet?
The ketogenic diet , or simply keto , is a low-carb , high-fat , moderate-protein diet. Unlike classic low-calorie diets, keto is not based on calorie counting , but on changing the primary energy source : from glucose to fat.
Its name comes from ketosis , a natural metabolic state in which the body, not having enough sugar to burn, begins to produce ketone bodies from fats. And these ketones become the main fuel.
⚙️ How Metabolism Works in Ketosis
Under normal conditions, the body uses glucose (derived from carbohydrates) for energy. However, when carbohydrate intake is drastically reduced (below 50 g net per day), liver and muscle glycogen stores are depleted in 1–3 days.
At that point, the liver begins to:
- transform fatty acids into ketone bodies (β-hydroxybutyrate, acetoacetate, acetone)
- send them into the bloodstream as a new energy source
- fuel your brain, muscles, heart and peripheral tissues without the need for sugar
This process, called ketogenesis , is behind the weight loss, appetite reduction, and blood sugar stabilization seen on the keto diet.
🧠 The main benefits of the ketogenic diet
✅ 1. Real and sustainable weight loss
- Promotes lipolysis (use of stored fat)
- Eliminates water retention due to carbohydrates
- Reduces appetite and hunger pangs
✅ 2. Glycemic and insulin control
- Maintains blood sugar levels constant
- Reduces insulin, promoting fat burning
- It can help in case of insulin resistance , type 2 diabetes , PCOS
✅ 3. Cognitive benefits
- Ketones fuel the brain continuously and less “energy crash”
- Many report greater concentration, clarity, less brain fog
✅ 4. Anti-inflammatory effect
- Reduction of inflammatory markers (CRP, IL-6)
- Positive effect in autoimmune diseases, chronic inflammatory diseases and joint pain
✅ 5. Therapeutic effects in the clinical setting
- Used for decades in the treatment of refractory epilepsy
- Emerging Studies on Alzheimer's, Parkinson's, Migraine, Brain Tumors
🍽️ What do you eat on a ketogenic diet?
The ketogenic diet is based on foods rich in healthy fats , quality protein sources , and low-carb vegetables .
✅ Allowed foods:
- Fats : extra virgin olive oil, butter, ghee, coconut oil, avocado
- Proteins : meat, fish, eggs, aged cheeses
- Low carb vegetables : zucchini, cauliflower, spinach, mushrooms, cucumbers
- Low carb fruit : avocado, olives, berries in controlled quantities
- Beverages : water, coffee, green tea, infusions
❌ Foods to avoid:
- Bread, pasta, rice, cereals, potatoes
- Sweets, biscuits, snacks, sugary drinks
- Sugary fruits (bananas, apples, grapes, mangoes)
- Legumes (beans, lentils, chickpeas)
- Ultra-processed industrial products
📊 How are macronutrients distributed?
A classic ketogenic diet includes:
| Macronutrient | Percentage | Function |
|---|---|---|
| Fats | 70–75% | Primary source of energy |
| Proteins | 20–25% | Maintaining muscle mass |
| Carbohydrates | 5–10% | (<50g net/day) |
Net carbs are calculated:
Total carbohydrates – Fiber – Polyols (if present)
⛑ Possible side effects and adaptation
“Keto flu” (keto flu)
It is a transitory phase in which the following may occur:
- tiredness
- heachache
- irritability
- nausea
- difficulty concentrating
📌 Remedies:
- increase your intake of electrolytes (sodium, magnesium, potassium)
- drink lots of water
- avoid training intensely in the first few days
Other effects:
- Acetone breath : temporary fruity odor
- Constipation : compensate with fiber from vegetables and water
- Menstrual loss or irregular cycles : transient, related to adaptation
👩⚕️ Is it suitable for everyone?
The ketogenic diet is not a universal diet . It is important to evaluate with a professional if it is compatible with your physical and clinical condition.
Contraindications:
- Pregnancy and breastfeeding (unless medically indicated)
- Advanced renal and liver disease
- Eating disorders (past or present)
- Use of hypoglycemic drugs: supervision required
🧬 What does science say?
- Type 2 Diabetes : Improved Insulin Sensitivity and Reduction of Drugs
- Obesity : Greater effectiveness than standard low-calorie diets in the first 6 months
- Neurology : documented efficacy in controlling epilepsy and promising in slowing down neurodegenerative diseases
- Inflammation and metabolic markers : significant reduction in triglycerides, blood sugar, blood pressure
📚 Sources:
- “Ketogenic Diet: Evidence for Optimized Fat Metabolism”, Frontiers in Nutrition
- “A low-carbohydrate, ketogenic diet to treat type 2 diabetes”, Nutrition & Diabetes
- “Ketone Bodies and Brain Metabolism”, Nature Reviews Neuroscience
🧩 Variations of the ketogenic diet
There are different variations of keto depending on your goal and lifestyle:
| Variant | Characteristics |
|---|---|
| Standard (SKD) | Classic Ketogenic: < 50 g carbohydrates |
| Cyclic (CKD) | Alternate keto days with high-carb days |
| Targeted (TKD) | Carbohydrates consumed around training |
| High protein | More protein, useful for athletes |
🔚 Conclusion
The ketogenic diet is a powerful, effective and increasingly studied nutritional tool. But like any strategy for intervening on the metabolism, it requires:
- Correct information
- Professional monitoring
- Custom adaptation
It is not a magic wand, but it can become a key to rebalance the body and improve health. With awareness, gradualness and attention.