Complete Keto Diet Guide
Everything you need to know about the ketogenic diet, from getting into ketosis to optimizing your macros for weight loss or muscle gain
Medical Disclaimer
What Is the Keto Diet?
The ketogenic diet (keto) is a very low-carbohydrate, high-fat eating plan designed to shift your body into a metabolic state called ketosis. In ketosis, your body burns fat for fuel instead of glucose (from carbs), producing molecules called ketone bodies that serve as an alternative energy source for your brain and body.
Originally developed in the 1920s to treat epilepsy, the keto diet has gained massive popularity for weight loss, mental clarity, and metabolic health. When you drastically reduce carbohydrate intake (typically to 20-50g net carbs per day), your liver converts fat into ketones, which provide steady energy without the blood sugar spikes and crashes associated with high-carb diets.
Unlike other low-carb diets, keto requires strict carb restriction to maintain ketosis. This metabolic shift typically takes 2-4 days but can vary based on individual factors like activity level, previous diet, and metabolic flexibility.
Keto Macro Breakdown (75/20/5)
The standard ketogenic diet follows a macro split of approximately 70-75% fat, 20-25% protein, and 5-10% carbohydrates. Here's what that looks like in practice:
Your primary fuel source. Focus on healthy fats: avocados, olive oil, nuts, fatty fish, butter, and coconut oil.
Moderate protein (1.6g per kg bodyweight). Too much can kick you out of ketosis via gluconeogenesis.
Typically 20-50g net carbs daily. This is non-negotiable for maintaining ketosis.
Calculate Your Personal Keto Macros
Foods to Eat on Keto
Healthy Fats & Oils
- • Avocado and avocado oil
- • Olive oil (extra virgin)
- • Coconut oil and MCT oil
- • Butter and ghee (grass-fed)
- • Animal fats (tallow, lard)
- • Nuts and nut butters (macadamia, almond, pecan)
- • Seeds (chia, flax, hemp, pumpkin)
Protein Sources
- • Fatty cuts of meat (ribeye, pork belly, chicken thighs)
- • Fatty fish (salmon, mackerel, sardines)
- • Whole eggs (most nutrient-dense keto food)
- • Full-fat dairy (cheese, heavy cream, Greek yogurt)
- • Bacon and sausage (watch for added sugars)
- • Organ meats (liver, heart - highly nutritious)
Low-Carb Vegetables
- • Leafy greens (spinach, kale, arugula, lettuce)
- • Cruciferous vegetables (broccoli, cauliflower, cabbage)
- • Zucchini and summer squash
- • Bell peppers and asparagus
- • Mushrooms and celery
- • Green beans and Brussels sprouts (in moderation)
Other Keto-Friendly Foods
- • Berries (raspberries, blackberries - small portions)
- • Dark chocolate (85%+ cacao)
- • Unsweetened almond/coconut milk
- • Sugar-free condiments (mustard, hot sauce, mayo)
- • Bone broth and sugar-free beverages
- • Keto sweeteners (stevia, erythritol, monk fruit)
Foods to Avoid on Keto
These foods will kick you out of ketosis due to high carb content:
High-Carb Foods
- • All grains (wheat, rice, oats, quinoa, corn)
- • Bread, pasta, cereal, and baked goods
- • Legumes (beans, lentils, chickpeas, peanuts)
- • Starchy vegetables (potatoes, sweet potatoes, peas)
- • Most fruits (bananas, apples, oranges, grapes)
- • Sugar in all forms (table sugar, honey, maple syrup, agave)
Processed & Unhealthy
- • Sugary drinks (soda, juice, sports drinks, sweet tea)
- • Low-fat and "diet" products (often high in sugar)
- • Processed meats with added sugars
- • Seed oils (canola, soybean, corn, vegetable oil)
- • Alcohol (beer, sweet cocktails, most wine)
- • Candy, cookies, ice cream, and desserts
Understanding Keto Flu
Keto flu is a collection of symptoms that some people experience during the first 3-7 days of starting keto. It's not actually the flu—it's your body adapting to using fat for fuel instead of carbs.
Common Symptoms:
How to Prevent or Minimize Keto Flu
1. Increase electrolytes: Supplement sodium (5,000mg), potassium (1,000-3,500mg), and magnesium (300-500mg) daily. Salt your food generously.
2. Stay hydrated: Drink at least 2-3 liters of water daily. Keto is diuretic, so you'll lose more water and electrolytes.
3. Eat enough fat: Don't fear fat—it's your primary fuel now. Not eating enough fat can leave you feeling depleted.
4. Transition gradually: If possible, reduce carbs over 1-2 weeks rather than going cold turkey.
5. Get adequate rest: Your body is undergoing a major metabolic shift. Prioritize sleep and reduce intense exercise initially.
Types of Ketogenic Diets
Standard Ketogenic Diet (SKD)
The most common approach: 70-75% fat, 20-25% protein, 5-10% carbs. Carbs stay consistently low every day. Best for most people, especially beginners.
Targeted Ketogenic Diet (TKD)
Adds 25-50g of fast-digesting carbs around workouts to fuel high-intensity exercise. Best for athletes who need explosive performance while staying mostly in ketosis.
Cyclical Ketogenic Diet (CKD)
Involves 5-6 days of standard keto followed by 1-2 "refeeding" days of higher carbs (100-150g). Used by bodybuilders and athletes to replenish glycogen while maintaining fat adaptation.
High-Protein Ketogenic Diet
Modified ratio: 60% fat, 35% protein, 5% carbs. Often used for muscle preservation during aggressive fat loss or by athletes who need more protein for recovery.
Health Benefits of Keto
Research suggests the ketogenic diet may offer several health benefits beyond weight loss:
Weight Loss and Fat Loss
Ketosis naturally suppresses appetite, making calorie restriction easier. Studies show keto can be more effective than low-fat diets for short-term weight loss.
Improved Blood Sugar Control
Keto dramatically lowers blood sugar and insulin levels, making it particularly beneficial for people with type 2 diabetes or prediabetes (under medical supervision).
Enhanced Mental Clarity
Many people report improved focus and reduced brain fog on keto. Ketones provide stable energy to the brain without blood sugar fluctuations.
Increased Energy and Endurance
Once fat-adapted (2-4 weeks), many people experience sustained energy throughout the day without crashes. Endurance athletes can tap into virtually unlimited fat stores.
Potential Therapeutic Benefits
Originally used for epilepsy, keto is being studied for Alzheimer's, Parkinson's, PCOS, certain cancers, and neurological conditions. More research is needed.
Improved Heart Health Markers
Keto typically increases HDL (good) cholesterol and can improve triglycerides. LDL response varies—some see increases, others don't. Monitor with bloodwork.
Tips for Keto Success
Track your macros initially using an app like MyFitnessPal or Cronometer. This ensures you stay under your carb limit and hit protein targets.
Meal prep and plan ahead. Having keto meals ready prevents you from reaching for high-carb convenience foods when hungry.
Read labels carefully. Hidden sugars and carbs lurk in sauces, condiments, processed meats, and "keto-friendly" products.
Don't fear fat. If you're low-carb AND low-fat, you'll feel terrible. Fat is your primary fuel source now—embrace it.
Electrolytes are crucial. Get 5,000mg sodium, 1,000-3,500mg potassium, and 300-500mg magnesium daily to feel your best.
Be patient with fat adaptation. It takes 2-4 weeks to become fully fat-adapted. Initial energy dips are normal.
Test your ketone levels if curious, but don't obsess over the numbers. Nutritional ketosis is 0.5-3.0 mmol/L, but everyone is different.
Stay consistent. Going in and out of ketosis repeatedly (yo-yoing) is harder on your body than sticking with it or choosing a different approach.
Frequently Asked Questions About Keto
What exactly is the keto diet?
The ketogenic (keto) diet is a very low-carb, high-fat diet that shifts your body into ketosis—a metabolic state where fat becomes your primary fuel source instead of carbohydrates. Typically, keto macros are 70-75% fat, 20-25% protein, and 5-10% carbs (usually 20-50g net carbs daily).
How long does it take to enter ketosis?
Most people enter ketosis within 2-4 days of restricting carbs to under 25g per day, though it can take up to a week for some. Signs include increased energy, reduced appetite, fruity breath, and measurable ketones via urine, breath, or blood testing.
What is keto flu and how do I avoid it?
Keto flu refers to flu-like symptoms (fatigue, headache, irritability, nausea) during the first week as your body adapts. Prevent it by staying hydrated, supplementing electrolytes (sodium, potassium, magnesium), eating enough fat, and gradually reducing carbs rather than cutting them abruptly.
Can I build muscle on keto?
Yes, you can build muscle on keto with adequate protein intake (1.6-2.0g per kg bodyweight) and proper strength training. Some athletes use targeted or cyclical keto to optimize performance. The key is eating enough calories and protein while maintaining ketosis.
Is keto safe long-term?
For most healthy adults, keto can be safe long-term with proper planning and nutrient-dense food choices. However, it's not suitable for everyone (pregnant women, people with certain medical conditions). Consult a healthcare provider before starting, especially if you have diabetes, kidney disease, or other health conditions.
How much weight can I lose on keto?
Weight loss varies widely based on starting weight, calorie deficit, and individual factors. Many people lose 5-10 lbs in the first week (mostly water weight), then 1-2 lbs per week thereafter. Sustainable fat loss requires a consistent calorie deficit regardless of diet approach.
Do I need to track macros on keto?
Initially, yes—tracking helps ensure you stay under your carb limit and hit protein goals. Many people eventually develop intuition for keto-friendly portions. At minimum, track net carbs to maintain ketosis. Use our keto macro calculator to determine your personalized targets.
What's the difference between net carbs and total carbs?
Net carbs are total carbs minus fiber (and sometimes sugar alcohols). Since fiber doesn't raise blood sugar or kick you out of ketosis, most keto dieters track net carbs. For example, if food has 10g total carbs and 7g fiber, it has 3g net carbs.