Medically, the classic ketogenic diet is used to help control seizures. But the very high-fat, low-carb diet has gone mainstream as a modified version that may be used as a weight-loss diet. Although you are allowed to eat foods from all food groups on the ketogenic diet, portions of certain types of food may be much smaller than those you're used to. Consult your doctor before making any changes to your diet.
About the Ketogenic Diet for Weight Loss
The goal of the ketogenic diet is to get your body in a state of ketosis, which is when your body uses fat instead of glucose for energy. This is done by modifying your diet so that a large percentage of your calories come from fat.
A ratio is used to determine the amount of carbohydrate you can have, which ranges from 4 grams of fat for every 1 gram of carbohydrate to 1 gram of fat for every 1 gram of carbohydrate. For someone trying to lose weight on a modified ketogenic diet, the amount of protein should be adequate to meet your needs, which is between 10 percent and 35 percent of calories, based on the 2010 dietary guidelines. For example, on a 1,200-calorie diet with a four-to-one ratio of fat to carbs and 20 percent of your calories from protein, you would be allowed 10 grams of carbs, 60 grams of protein and 102 grams of fat. On a one-to-one ratio, you would be allowed 60 grams of carbs and 80 grams of fat, with the same amount of protein.
Fat and Protein Foods to Eat on Ketogenic Diet
To maintain ketosis -- which helps you burn body fat -- fat and protein should make up the bulk of your intake on the ketogenic diet. Healthy fat options include vegetable oils such as olive oil, safflower, sunflower, canola, peanut and sesame oil, along with mayonnaise. Heavy cream and coconut oil may also be used as sources of fat on the ketogenic diet. However, these fats are high in saturated fat, and should be used sparingly.
To meet your protein needs, poultry, lean red meat, eggs, seafood and tofu make good choices. Salmon, tuna and sardines are rich in protein and in essential omega-3 fatty acids, and make a healthy source of protein and fat on your diet plan.
Carb Choices on Ketogenic Diet
It's good to eat a wide variety of foods from all food groups on a ketogenic diet -- but because of the macronutrient ratios, your carb choices may be limited. To get the greatest number of nutrients from carb-containing foods, include those that are rich in vitamins and minerals. Healthy choices include fruits such as berries, watermelon, cantaloupe and oranges, and non-starchy vegetables such as spinach, lettuce, broccoli, green beans, mushrooms, cucumbers and asparagus.
Whole grains, bread and other healthy starches, such as sweet potatoes and winter squash, are a more concentrated source of carbohydrates. You may include these foods in your diet if they have been calculated to fit in your plan. For example, you can save all your carbs for breakfast so you can have a slice of toast or 1/2 cup of oatmeal.
Foods to Avoid
To sustain ketosis and good health, you need to avoid high-carbohydrate foods that offer very little nutritional value. These foods include candy, cookies, ice cream, soda, pies, pastries and refined-flour bread products and cereal. You also want to avoid added sweeteners such as sugar, honey, jam, jelly and sweet condiments such as catsup and salad dressing.
A Typical Day on Ketogenic Diet
Foods should be carefully weighed and measured when following a ketogenic diet. For breakfast on a low-calorie plan with a four-to-one ratio, you might have a three-egg omelet, cooked in 1 tablespoon of vegetable oil and filled with 1/2 cup of raw spinach. This meal contains 30 grams of fat, 22 grams of protein and 3 grams of carbohydrates.
At lunch, try 3 ounces of salmon cooked in 2 teaspoons of olive oil, with 1/2 cup of mixed greens topped with 2 teaspoons of olive oil, for 29 grams of fat, 22 grams of protein and 3 grams of carbs.
One cup of firm tofu, stir-fried in 1 tablespoon of sesame oil, makes a ketogenic dinner option, and has 30 grams of fat, 14 grams of protein and 5 grams of carbohydrates.
Things to Consider
The ketogenic diet is a very restrictive diet and should only be followed under the direction of a physician. It's also not meant to be followed long-term. Although a 2004 study published in Experimental and Clinical Cardiology found that a more liberalized version of the diet -- up to 30 grams of carbohydrates -- was safe to follow for weight loss for 24 weeks. Additionally, due to the limited food options, you may find the diet difficult to follow.
Due to the macronutrient ratios, you may have a hard time meeting nutrient needs. You may want to add a multivitamin and a mineral supplement to ensure all needs are met.