The keto diet is an eating approach with a very low carbohydrate intake and a high fat intake that leads to a state of ketosis—your body starts using ketones made from fat as its primary energy source. A typical macro range on keto is roughly 70–80% of calories from fat, 10–20% from protein, and 5–10% from carbohydrates (often under 50 g of carbs per day). These ratios can vary slightly depending on goals and health status.
Who might keto make sense for?
- Weight loss and improved metabolic markers: When followed consistently, keto can reduce body weight in the short term and improve some parameters (fasting glucose, blood pressure, triglycerides).
- Type 2 diabetes (with medical supervision): Professional guidelines allow low-carb eating as one option that may improve glycemic control and reduce medication needs.
- Epilepsy (medical use): The ketogenic diet has an established role in treating drug-resistant epilepsy in children and adults—always under medical supervision.
Who is keto not suitable for?
Keto is not suitable (or is only suitable after careful consideration with a doctor) for pregnant and breastfeeding women; people with eating disorders; those with liver or pancreatic disease; advanced kidney disease; uncontrolled type 1 diabetes (risk of ketoacidosis); and for children or adolescents without a medical indication and professional oversight.
How to start: a practical 5-step plan
- Set a goal and a time frame. Keto works best as a clearly defined phase (e.g., 8–12 weeks); afterward, consider transitioning gradually to a long-term sustainable approach.
- Set your macros. Start with ~20–30 g net carbs per day, keep protein moderate (about 1.2–1.6 g/kg of lean body mass), and make up the rest with quality fats (olive oil, avocado, nuts, seeds, fatty fish).
- Plan your meals and grocery shopping. Cut out bread and pastries, rice, pasta, potatoes, sugar, and sugary drinks. Instead, focus on eggs, meat and fish, cheese (in moderation), non-starchy vegetables, olives, avocado, nuts, and seeds.
- Mind electrolytes and fiber. In the first days, increase fluids, sodium, potassium, and magnesium; eat leafy greens and seeds for fiber.
- Track how your body responds. In the first week, you may experience the so-called “keto flu” (fatigue, headache). It usually improves after adjusting hydration and electrolyte intake.
Sample 7-day meal plan (20–30 g carbs/day)
Adjust portions to your energy needs; include low-carb vegetables at each meal (spinach, zucchini, broccoli, cucumber, lettuce).
Day 1
- Breakfast: Egg omelet with baby spinach and feta
- Lunch: Salmon in butter, arugula and avocado salad
- Dinner: Herb-roasted chicken thighs, steamed cauliflower
- Snack: A handful of walnuts
Day 2
- Breakfast: Full-fat Greek yogurt with chia seeds
- Lunch: Tuna salad with olives and olive oil
- Dinner: Pork tenderloin, sautéed mushrooms
- Snack: Olives
Day 3
- Breakfast: Scrambled eggs with avocado
- Lunch: “Zoodles” (zucchini noodles) with pesto and Parmesan
- Dinner: Beef steak, kale salad with pumpkin seeds
- Snack: Parmesan crisps (thinly sliced hard cheese)
Day 4
- Breakfast: Full-fat quark with cinnamon and a few raspberries
- Lunch: Sardines in olive oil, cucumber salad
- Dinner: Turkey meatballs in tomato sauce (no added sugar), zucchini “spaghetti”
- Snack: Almond butter (1 tbsp)
Day 5
- Breakfast: Egg salad with mayonnaise and chives
- Lunch: Baked mackerel, sugar-free coleslaw
- Dinner: Chicken breast cooked in coconut oil, broccoli with butter
- Snack: A handful of almonds
Day 6
- Breakfast: Omelet with goat cheese and herbs
- Lunch: Zucchini fritters (egg, Parmesan) with sour cream
- Dinner: Pulled pork with leafy salad greens
- Snack: Avocado with salt and lemon
Day 7
- Breakfast: “Keto” smoothie (unsweetened almond milk, spinach, a spoon of peanut butter)
- Lunch: Niçoise salad (eggs, tuna, green beans—in moderation)
- Dinner: Baked salmon/trout, asparagus with hollandaise sauce
- Snack: Cashews (a small handful)
Grocery list
Eggs; fatty fish (salmon, mackerel, sardines); poultry and red meat (rotate, don’t overdo processed meats); hard cheeses; full-fat Greek yogurt and quark (in moderation); avocado; olives; leafy greens and cruciferous vegetables; zucchini; mushrooms; nuts and seeds; olive oil, butter, or ghee; herbs and spices; plain mineral water.
Evidence-based benefits and limitations
- Short-term benefits: With low carbs, weight loss and improvements in some risk factors are commonly observed (especially triglycerides, blood glucose, blood pressure).
- Long-term data are mixed: After a year, the difference in weight loss versus balanced diets often narrows; sustainability is individual.
- Type 2 diabetes: Expert consensus and standards of care recognize low-carb eating as an option that can improve HbA1c and reduce medication needs, if it is implemented safely and individualized.
- Epilepsy: The ketogenic diet is an established therapy for drug-resistant epilepsy with demonstrated reductions in seizure frequency—exclusively under medical supervision.
Risks, side effects, and what to watch out for
- “Keto flu” in the first week: fatigue, headache, nausea—often helped by adequate fluids and electrolytes.
- Constipation and potential nutrient deficiencies: low fiber intake and lower intake of some micronutrients—addressed by a varied selection of allowed foods and plenty of leafy greens.
- Changes in blood lipids: in some people, LDL cholesterol may rise—monitor your values and prioritize unsaturated fats (olive oil, nuts, fish).
- Kidney stones and uric acid: with long-term, very strict approaches, increased risk has been reported; hydration and a well-balanced menu matter.
- Ketoacidosis: a dangerous condition typical especially for type 1 diabetes; if you have T1D, don’t attempt keto without a doctor.
How to “exit” keto safely
Increase carbohydrates gradually (e.g., +10–15 g every 5–7 days), starting with berries and legumes in small portions. Monitor your weight and glucose levels (if you have diabetes), and adjust fat intake downward.
Tips for sports and everyday life
Shortly after starting keto, performance may dip; after adaptation, it usually stabilizes. For intense training, “targeted keto” (a small dose of carbs before performance) can work—individualized and after consulting a professional.
Alternatives if strict keto doesn’t work for you
Many people do better with low-carb (not fully keto) eating or a Mediterranean pattern—quality proteins, lots of vegetables, whole grains in reasonable amounts, olive oil, nuts, fish. What matters most is long-term sustainability and food quality.
Video: The ketogenic diet and epilepsy (expert perspective)
A short expert video from Johns Hopkins (in English) explaining when and why the ketogenic diet is used for epilepsy:
Summary
The keto diet can be a tool—not the goal. For some, it brings quick, motivating changes; for others, it won’t be a good fit. If you’re a healthy adult and want to try it, plan ahead, monitor outcomes (including blood lipids), and have a strategy for returning to a balanced long-term approach. If you have a chronic condition, proceed only with a healthcare professional.
Sources
- The Nutrition Source (Harvard T.H. Chan): Diet Review – Ketogenic Diet for Weight Loss — https://nutritionsource.hsph.harvard.edu/healthy-weight/diet-reviews/ketogenic-diet/
- Cleveland Clinic: Ketosis – Definition, Benefits & Side Effects — https://my.clevelandclinic.org/health/articles/24003-ketosis
- American Diabetes Association (Diabetes Care): Nutrition Therapy for Adults With Diabetes or Prediabetes (Consensus Report, 2019) — https://diabetesjournals.org/care/article/42/5/731/40480/Nutrition-Therapy-for-Adults-With-Diabetes-or
- Cochrane Library: Ketogenic diets for drug-resistant epilepsy (Review) — https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001903.pub5/full
- Johns Hopkins Medicine: Ketogenic Diet Therapy for Epilepsy — https://www.hopkinsmedicine.org/neurology-neurosurgery/specialty-areas/epilepsy/diet-therapy
Jana
I like turning curiosity into words, and writing articles is my way of capturing ideas before they slip away — and sharing them with anyone who feels like reading.
