4 Ketogenic Diet Variations

What Is the Ketogenic Diet?

The high-fat, moderate-protein, low-carb ketogenic diet, better known as the "keto diet," is controversial. The idea behind the keto diet is that when you lessen your carbohydrate intake (in this case, less than 50 grams per day), your body enters a metabolic state called nutritional ketosis.

Nutritional ketosis is when your body finds an alternate energy source—because it usually gets energy from glucose—and instead uses ketones, molecules produced from fatty acids, according to a review published in September 2018 in Current Nutrition Reports. Nutritional ketosis possibly results in weight loss.

The keto diet was initially developed to treat childhood epilepsy, according to a November 2021 overview in StatPearls. Per a review published in June 2013 in the European Journal of Clinical Nutrition, the keto diet may also help people with:

• Cardiovascular disease
• Type 2 diabetes
• Acne
• Cancer
• Polycystic ovary syndrome (PCOS)
• Neurological disorders—A review published in May 2022 in Nutrients stated the keto diet could affect both the progression of these disorders and the outcome of their treatments.
• Alzheimer's disease
• Parkinson's disease

The keto may result in weight loss when maintained for a maximum of 12 months, according to a review published in February 2014 in the International Journal of Environmental Research and Public Health. But its long-term health effects are unclear. StatPearls also notes that early weight loss while on the keto diet may be water weight loss. And a review published in June 2013 in the European Journal of Clinical Nutrition pointed out that weight loss during the keto diet may be from eating fewer calories overall and not from a metabolic change.

What Foods Do You Eat on the Keto Diet?

Generally, the ketogenic diet requires eating lots of fats, moderate amounts of protein, and few carbohydrates. But different fats, proteins, and carbohydrates can affect your health differently.

While no food is "good" or "bad," it's important to understand the nutrients in the food you eat. For example, according to the American Heart Association (AHA), eating foods high in saturated fat—like beef, poultry, butter, cheese, oil, and fried foods—can affect your cholesterol levels and increase your risk of heart disease. The AHA recommends eating unsaturated fat sources like avocados, olives, walnuts, liquid vegetable oils, salmon, trout, and herring.

Keto Diet Side Effects

Short-term side effects of the keto diet include, to StatPearls:

• Nausea
• Vomiting
• Headache
• Fatigue
• Constipation
• Dizziness

These symptoms felt days after starting a keto diet are sometimes called "keto flu." You may also have difficulty sleeping or working out. For example, a study published in April 2018 in The Journal of Sports Medicine and Physical Fitness found that after four days on the keto diet, people had difficulty performing anaerobic exercise (high-intensity, short bursts of activity).

Is the Keto Diet Safe and Sustainable?

While the keto diet may lead to short-term weight loss, its long-term health effects need further studies. Changing your macronutrient (carbohydrates, protein, and fat) intake could lead to vitamin and mineral deficiencies, StatPearls notes. A study published in September 2018 in The Lancet Public Health found both high- and low-carbohydrate diets had an association with higher mortality risk but suggested eating more plant-derived protein than animal-derived protein could decrease mortality risk.

More studies are required to understand if following the keto diet for more than two years is recommended and what happens when you discontinue the diet.

Furthermore, a study published in May 2018 in Diabetic Medicine suggested the keto diet may not be safe for people with type 1 diabetes.

No study has analyzed if it is safe for pregnant people to follow a keto diet, according to an overview published in October 2020 in Obesity Reviews.

The keto diet is restrictive and may be challenging to follow for long periods. It's worth mentioning, too, that weight loss is a personal decision. Losing weight does not automatically make you "healthier," and discussing your weight loss goals and methods with a healthcare provider may be helpful.

An overview published in June 2020 in the Journal of Nutrition concluded that a "well-formulated keto diet" does not pose significant safety concerns for the general public. The overview noted that "high-quality clinical trials" should be conducted to understand the keto diet's long-term effects and full potential.

Keto Diet Variations

Following a keto diet requires you to calculate your macronutrient ratio. This means making sure you eat specific percentages of carbohydrates, proteins, and fats every day. However, counting macronutrients and cutting your intake may prove restrictive and challenging to sustain.

A few more-flexible keto variations exist. In September 2018, the Indian Journal of Medical Research (IJMR) summarized four types of modified keto diets. On these, your body may go in and out of ketosis. Learn the macronutrient ratios of the standard keto diet and its variations below.

Standard Ketogenic Diet (SKD)

Macronutrient ratio: 70% fat, 20% protein, 10% carbs

The standard keto diet is the strictest. You'll eat less than 50 grams of carbs each day, according to the IJMR. So if you eat about 2,000 calories per day, you will get about 1,400 calories from fat, 400 calories from protein, and 200 calories from carbs. However, the May 2022 review in Nutrients noted that the initial phase of this diet could require eating less than 20 grams of carbs each day, which can be pretty restrictive.

Targeted Keto Diet (TKD)

Macronutrient ratio: 65-70% fat, 20% protein, 10-15% carbohydrates

The targeted keto diet is popular among athletes and active individuals who live a keto lifestyle but need more carbs for energy. It allows an additional 20-30 grams of carbs immediately before and after workouts. The total carb count comes to 70-80 grams per day. Healthy carb sources include fruit, dairy, grain-based foods, or sports nutrition products.

Cyclical Keto Diet (CKD)

Macronutrient ratio: 70-75% fat, 15-20% protein, 5-10% carbohydrates on "keto days;" 15% fat, 15% protein and 70% carbohydrates on "off days"

Keto cycling is a way to cycle in and out of ketosis while eating a more balanced diet. One approach includes five days of the standard keto diet and two non-keto days per week.

A study published in September 2020 in Nutrients found that while the cyclical keto diet (following the above macronutrient ratio percentages) could reduce body weight in "healthy young men," it could not effectively increase aerobic or strength performance.

High-Protein Keto Diet (HPKD)

Macronutrient ratio: 60% fat, 35% protein, 5% carbohydrates

This plan entails eating about 120 grams of protein per day (or four 4-ounce servings of meat, fish, or poultry) and around 130 grams of fat per day. Carbs are still restricted to less than 5% of daily calories, according to the IJMR. But many people find this modified keto diet easier to follow because it allows you to eat more protein and less fat than the standard keto diet. However, this approach may not result in ketosis because your body can still convert protein into glucose for fuel.

The Bottom Line

While the ketogenic diet might lead to short-term weight loss, its long-term effects are unclear. Modified keto diets exist that may be less restrictive and therefore easier to sustain. If possible, talk to a healthcare provider before changing your diet.