“Low carb diet” and “keto diet” are terms that get casually thrown around in conversations. And while people often use these diet terms interchangeably, there are key differences and things to note about each diet before choosing which one works best for you.
What is a Low-Carb High-Fat (LCHF) Diet?
There is no concrete definition of a low-carb, high-fat diet. In essence, it’s any meal plan that follows the philosophies of the diet’s name itself.
Example low-carb, high-fat diets include the Atkins Diet, created in the 1950s, and the South Beach Diet, which rose to fame in 2003.
In the former, which was created by Dr. Robert Coleman Atkins, you go through several dietary phases. In the first phase, you eat approximately 30 grams of carbohydrates a day, along with unlimited fat and protein.
In the latter, which was created by cardiologist Arthur Agatston, you eat a modified low-carb diet. In the beginning, approximately 45% of your calories come from carbs, but by the final phase, only 28% of your daily calories are derived from carbs. The bulk of your remaining calories are supposed to come from healthy fats and protein.
As you can see, there’s significant wiggle room in terms of what can be defined as a low-carb, high-fat diet.
What is a Ketogenic Diet?
On the other hand, a ketogenic diet comes with much stricter parameters. It was created in the early 1900s by Dr. Russell Wilder. A true ketogenic diet allows just 5% of your daily calories to come from carbohydrates. The rest of your calories should come from fats (75% of your daily calories) and protein (20% of your daily calories).
As its name suggests, the focus of this style of eating is on ketone bodies. When followed strictly, the idea is that your body shifts into a constant state of nutritional ketosis.
On such an ultra-low carb meal plan, your liver breaks the fat you eat into ketone bodies and fatty acids. The proponents of this diet say that by eating a ketogenic diet, you force your system to use ketone bodies as energy.
What Does the Science Say?
Because of the shifting definitions of a low-carb diet, clear research results are difficult to come by. However, there are some studies that suggest using fat for fuel (as one would do when on a ketogenic diet) could bring with it some benefits.
For example, a 2015 study published in the European Journal of Sport Science notes that “keto-adaptation” (using fat for fuel instead of carbohydrates) “could extend human physical and mental performance beyond current expectation.”
This supports older research, such as one published in the Metabolism research journal in the 1980s, that suggested the same thing.
Other benefits pushed by supporters of the ketogenic diet philosophy include:
- Improved body fat composition. The idea is that by encouraging your body to see fat as fuel, you ramp up how your body burns its own fat.
- Better blood sugar levels. The theory is that by restricting your intake of carbohydrates, you avoid the constant blood sugar spikes that occur whenever you eat carbs.
- Improved brain health. Supporters of high-fat diets point out that your brain uses fat for energy, and the theory is that higher dietary fat intake can improve your mental performance.
Which Diet is Right For You?
The right diet for you depends on your goals, your lifestyle, and factors like your age and gender.
For example, for diabetics, we strongly endorse the Low Carb High Fat (LCHF) diet for reversing the condition.
Some women find that an extremely low-carb approach to meals can negatively impact their menstruation cycles. Other people find that following a ketogenic meal plan makes them feel fatigued and sluggish. For these reasons, always talk to your doctor or a registered dietitian if you’re considering any changes to your diet.