What is the Ketogenic Diet?

A ketogenic (keto) diet is a way of eating that is very low in carbs, high in fat, and moderate in protein. The goal is to get your body into a state called ketosis, where it burns fat instead of sugar for energy.

How Your Body Uses Fuel

Your body has two main fuels: sugar (from carbs) and fat. Most people today burn sugar because they eat lots of carbs and have constant access to food.

Carbs are broken down into glucose, which your cells use for energy. While glucose is important, you don’t need to eat carbs for survival—your body can make the glucose it needs, even when you’re fasting.

The keto diet cuts carbs dramatically, so your body starts using fat for energy. When fat is burned, it produces ketones, which your brain and body can use instead of glucose. This also helps protect your muscles from being broken down for energy.

What Makes Keto Unique

Unlike other diets, the ketogenic diet is defined by a measurable biomarker—ketones. When you’re in ketosis, you can detect ketones in your blood, urine, or breath. High ketone levels show that your body is burning fat efficiently.

The diet was originally developed in the early 1900s to mimic the effects of fasting. Doctors used it to help people with epilepsy because fasting (and later keto) could reduce seizures. Over time, people discovered that keto can help with weight loss and many other health benefits.

What You Eat on Keto

A well-formulated keto diet focuses on whole, quality foods, like:

Fatty cuts of meat and poultry with skin

Fatty fish (salmon, mackerel)

Eggs

Healthy oils (coconut, olive, avocado, MCT)

Butter or ghee

Avocados and coconut

Low-sugar berries (e.g., wild blueberries)

Nuts and seeds

Leafy greens and cruciferous vegetables (broccoli, cauliflower, cabbage)

Other low-carb veggies (celery, cucumber, mushrooms, zucchini, onions, garlic)

Carbs are usually limited to 50g per day, protein is moderate, and the rest of your calories come from fat.

Typical macronutrient breakdown:

65–85% fat

15–35% protein

0–10% carbs

Everyone’s keto diet looks a bit different depending on your body, lifestyle, and goals.

How to Know if You’re in Ketosis

You can check for ketosis in three main ways:

Blood ketones – the most accurate method, using a meter and strips to measure BHB.

Urine ketones – tests for AcAc, but becomes less accurate as your body adapts to using ketones.

Breath ketones – measures acetone in your breath; an easy and non-invasive method.

Other signs you might be in ketosis include more energy, reduced hunger, mental clarity, and “fruity” breath.

or simply put.....Keto Cheat Sheet: Beginner’s Guide

Goal: Burn fat, not sugar, by entering ketosis.

What to Eat

Fat & Protein: Fatty meats, poultry with skin, fatty fish, eggs, butter, ghee, coconut, olive, and avocado oils

Low-Carb Veggies & Fruits: Leafy greens, broccoli, cauliflower, cabbage, Brussels sprouts, celery, cucumber, mushrooms, zucchini, onions, garlic, small amounts of berries

Extras: Nuts, seeds, avocado, coconut

What to Avoid

Bread, pasta, rice, grains, sugar, sweets, starchy vegetables, most fruits

Macros (Approx.)

65–85% fat | 15–35% protein | 0–10% carbs (<50g/day)

Signs You’re in Ketosis

More energy, less hunger, clearer thinking, fruity breath

Testing: Blood meter (most accurate), urine strips (easy), breath meter (simple)