Quick Answer
The ketogenic (keto) diet is a low-carb, high-fat eating plan that shifts your body into a metabolic state called ketosis, where it burns fat for fuel instead of carbohydrates. Typically 70-75% fat, 20-25% protein, and 5-10% carbs.
Understanding the Ketogenic Diet
The ketogenic diet is a radical departure from the standard American diet. Instead of relying on glucose from carbohydrates for energy, the keto diet forces your body to burn fat by drastically reducing carb intake and increasing fat consumption.
When you eat very few carbs (typically 20-50g net carbs per day), your liver converts fat into molecules called ketones, which become your body's primary fuel source. This metabolic state is called ketosis.
How Does Ketosis Work?
Here's what happens when you enter ketosis:
- Carb Restriction: You limit carbs to 20-50g per day
- Glycogen Depletion: Your body uses up stored glucose (glycogen) in 2-3 days
- Fat Breakdown: Without glucose, your body starts breaking down fat
- Ketone Production: Your liver converts fatty acids into ketones
- Ketosis: Your brain and body run on ketones instead of glucose
Macronutrient Breakdown
A standard ketogenic diet follows these ratios:
- Fat: 70-75% of daily calories (butter, oils, avocados, nuts)
- Protein: 20-25% of daily calories (meat, fish, eggs)
- Carbs: 5-10% of daily calories (vegetables, small amounts of berries)
For a 2,000 calorie diet, this translates to roughly 165g fat, 75g protein, and 20g net carbs.
Health Benefits of the Keto Diet
Weight Loss
Keto is highly effective for weight loss. By burning fat for fuel and reducing insulin levels, your body becomes a fat-burning machine. Studies show people lose 2-3x more weight on keto compared to low-fat diets.
Mental Clarity & Focus
Many people report improved mental clarity, focus, and concentration on keto. Ketones are a highly efficient fuel source for the brain.
Stable Energy Levels
Without the blood sugar spikes and crashes from carbs, keto provides steady, consistent energy throughout the day.
Reduced Appetite
High-fat foods are incredibly satiating. Most people naturally eat less on keto without feeling hungry.
Blood Sugar Control
Keto dramatically lowers blood sugar and insulin levels, making it beneficial for people with type 2 diabetes or prediabetes.
Potential Side Effects (The "Keto Flu")
During the first week, you might experience:
- Headaches and fatigue
- Brain fog and irritability
- Muscle cramps
- Nausea or digestive issues
These symptoms are temporary and caused by your body adapting to burning fat. They usually resolve within 3-7 days. Stay hydrated and increase salt intake to minimize symptoms.
How to Start the Keto Diet
- Calculate your macros using a keto calculator
- Clean out your pantry - remove high-carb foods
- Stock up on keto staples - eggs, meat, cheese, vegetables
- Plan your meals for the first week
- Track your intake using an app like MyFitnessPal
- Test for ketosis using urine strips or a blood meter
Who Should Avoid Keto?
Consult a doctor before starting keto if you:
- Have type 1 diabetes
- Are pregnant or breastfeeding
- Have a history of eating disorders
- Have kidney disease
- Take medications for diabetes or high blood pressure
Common Keto Myths Debunked
Myth: "Keto is bad for your heart"
Research shows keto improves most heart disease risk factors including triglycerides, HDL cholesterol, and blood pressure.
Myth: "You'll lose muscle on keto"
With adequate protein intake (0.8-1g per pound of lean body mass), you'll preserve and even build muscle on keto.
Myth: "Keto is too restrictive"
There are thousands of delicious keto recipes. With creativity, you can enjoy pizza, bread, desserts, and more in keto-friendly versions.