By now pretty much every health and fitness enthusiast and yo-yo dieter has heard about the ketogenic diet. Originally researched, developed and used under medical supervision in children with epilepsy and other neurological disorders, the ketogenic diet has taken the rest of the world by storm and not without much confusion and controversy.
The human body has a hierarchy for preferred sources of energy, carbohydrates being at the top of the list. Next in line is fats, and then finally proteins. The current health status and reason for employing a ketogenic diet usually dictate how much of each macronutrient are consumed; carbs, fats and protein.
The first and most important concept in the ketogenic diet is consuming a limited number of carbs daily, usually 25g or less, to force the body into a state called "ketosis".
Before we go any further, let's dig a little deeper into ketosis and the benefits. By limiting carbohydrates, which is the body's fuel of choice, the body responds by using fat as the next available energy source. Fatty acids also get released from the cells and transferred to the liver.
The liver turns the fatty acids into ketones. Ketones are spectacular molecules that cross the blood-brain barrier to provide a power source to the brain in the absence of glucose.
A carb-loaded diet is a disaster waiting to happen. Carbohydrates turn into blood sugar (glucose). Glucose is a fantastic fuel on a cellular level when it's at normal levels. Too much glucose causes the production of insulin to regulate blood sugar levels.
Over time too much insulin production can lead to insulin resistance and problems with diabetes and metabolic syndrome.
Recap: 1) Ketosis forces the body to burn fat for fuel, 2) Ketosis aids in glucose regulation. These are key components to how each of the ketogenic diets function and why someone would choose one over another.
Ketogenic Diet Types
The word "diet" carries some misconception. It can either mean the kinds of foods a person habitually eats or a special course of foods/food restrictions either for weight loss or medical reasons. In the keto-world, the word means both.
The ketogenic diet can be either a permanent way of eating or a temporary weight loss program. The individual needs and goals of the person using the ketogenic diet should be considered through the entire process.
" Standard Ketogenic Diet (SKD)
In this version, the ratio is typically 5% carbs, 75% fat and 20% protein. The numbers for fat and protein may shift a little, but for the most part, fat is a huge part of the diet and caloric intake. This extremely popular version utilizes a super simple concept; stay at or below carb limit to remain in ketosis.
" High-Protein Ketogenic Diet
Ketosis is achieved the same as in the standard ketogenic diet however in this model there is a bit more protein. A normal macronutrient ratio might look like 55-60% fat, 35-40% protein and still 5% carbs. As with the SKD, one must remain at or below the carb limit for ketosis to work its magic.
" Targeted Ketogenic Diet (TKD)
Ever heard of carb-loading before a workout? This is the main idea with the targeted ketogenic diet. About 30-60 minutes prior to exercise the participant should consume anywhere from 25-50g of easily digestible carbs (the actual number depends on the individual's needs and type of workout).
Glucose-based foods are used more efficiently than fructose-based and are usually burned completely without throwing the body out of ketosis. Post-workout meals should include plenty of protein and be less fatty. Normally fat is encouraged, however for muscle recovery and nutrient absorption, protein is a better choice here.
" Cyclical Ketogenic Diet (CKD)
This one sounds a bit strange considering what we've just learned. CKD is geared toward bodybuilders and athletes who wish to build lean muscle mass and still maximize fat loss.
In this regimen the SKD is followed for five days before cycling into the two-day phase of carb-loading. On the first day one might have a limit of 50g of carbs. On the second day the carb count could be anywhere from 400-600g. The premise is to load up on carbs so the body is properly fueled for the next five days of grueling workouts.
The CKD should not be used as a "cheat day" for those using the standard ketogenic diet protocol. This approach is suitable only for extremely active individuals.
" Restricted Ketogenic Diet
On this last version, both carbs and calories are limited and is typically supervised by medical professionals. Based on studies, cancer cells can't use ketones for energy and quite literally can starve to death.
As with any diet regimen or lifestyle change, one should seek the advice of their primary care provider before beginning. Medical history and current state of health should be considered, as well as the person's individual needs and goals.