How Does the Ketogenic Diet Work?
Normally, the body uses carbohydrates (glucose) as its main energy source. The ketogenic diet drastically reduces carbohydrates to less than 20–50 g per day, forcing the liver to produce ketone bodies from stored fats.
This metabolic state is called ketosis. The brain and muscles then use ketone bodies (beta-hydroxybutyrate, acetoacetate) instead of glucose.
| Macronutrient | % of Calories | Example (2000 kcal) |
|---|---|---|
| Fat | 65–75% | 144–167 g |
| Protein | 20–30% | 100–150 g |
| Carbs | 5–10% | 25–50 g |
Allowed and Forbidden Foods on Keto
| ✅ Allowed | ❌ To Avoid |
|---|---|
| Meats, poultry, fatty fish | Bread, pasta, rice, cereals |
| Eggs | Potatoes, sweet potato |
| Hard cheeses | Sugary fruits (banana, grapes, mango) |
| Avocado, olives | Legumes (beans, lentils) |
| Green vegetables (spinach, zucchini, broccoli) | Sugary drinks, fruit juices |
| Nuts, almonds, seeds | Beer, sweet wines |
| Olive oil, butter, cream | Candy, cakes |
How to Enter Ketosis: The Steps
Entering ketosis generally takes 2 to 7 days depending on your metabolism and activity level:
- Days 1–2: Body depletes liver and muscle glycogen stores (~500g). Significant water loss (1–3 kg).
- Days 3–5: Ketone body production begins. Possible keto flu: fatigue, headaches, irritability. Drink more water + electrolytes (sodium, potassium, magnesium).
- Days 7–14: Metabolic adaptation. Energy returns, hunger decreases, ketosis is established.
- Weeks 3–4: Full adaptation. The brain functions efficiently on ketone bodies.
Tip: Exercise speeds up ketosis entry by depleting glycogen stores faster.
Scientifically Proven Benefits
- Weight loss: faster short-term than low-fat diets (meta-analysis, 13 studies)
- Blood sugar control: reduces HbA1c by 1.5% on average in type 2 diabetics
- Triglyceride reduction: -30 to -40% in most studies
- Refractory epilepsy: reduces seizures by 50% in ~50% of patients
- Mental clarity: reported by ~70% of users after 4 weeks of adaptation
Risks and Contraindications
- Keto flu (transient): monitor electrolytes — salt, potassium, magnesium
- Constipation: increase fiber-rich green vegetables
- LDL cholesterol: may increase in some people (monitor)
- Not recommended: pregnancy, breastfeeding, kidney disease, liver disorders
- Consult your doctor if you take hypoglycemic medications
The ketogenic diet is powerful but demanding. The key to success is precise macro tracking. Nutrya automatically calculates your personalized ketogenic targets and alerts you when you go outside the optimal range.