Low-carb, high-fat diets (LCHF) are all the rage these days. Study after study shows remarkable results in rapid weight loss, cardiovascular health improvements, blood sugar maintenance, and mental clarity. The ketogenic diet is the most popular and well-known of the low-carb diets, but are there others? Do they have the same effects? 

The main hallmark of the ketogenic diet is the metabolic shift from burning glucose for fuel to burning ketones. It's when your body is in a state of ketosis that many of these health benefits are possible. But is that the only way? 

Let's explore the various versions of low-carb, high-fat diets, their safety, and potential side-effects, how effective they are, and a few alternative approaches to consider.

Defining Low-Carb, High-Fat Diets

As the name suggests, diets that put an emphasis on dietary fat as the main source of calories are considered high-fat. When you are also restricting carbohydrates, you get the LCHF diets we'll be examining today. While each of the diets that fall into this category has specific recommendations and restrictions, they all follow the same basic principle: reduce carbohydrates to a very low number and replace those calories with fats. 

The distinctions between the various LCHF diets are in the details. And if we're being totally honest, in some cases, it's just in the branding. There are a number of modern diet plans that fall into LCHF category, many of which began with the same ideals as the keto diet. 

The Ketogenic Diet (aka Keto Diet)

Developed at the Mayo Clinic in the 1920s by Dr. Russell Morse Wilder, the keto diet's initial medical application was in the treatment of severe epilepsy. It was discovered that elevated ketone bodies somehow effectively prevented seizures. 

Over years of study on the effects of the keto diet, a number of other health benefits came to light, including dramatic weight loss, lower blood pressure, lower LDL cholesterol, and lower blood sugar levels. In other words, this diet is often recommended for patients with type 2 diabetes, heart disease, and obesity. 

Keto is also being studied as a therapeutic diet for certain types of cancer and neurodegenerative diseases like Parkinson's and Alzheimer's disease. More work needs to be done before it's part of the recommended treatment plan, but the results are promising.

These benefits are due, in large part, to the metabolic changes that your body undergoes while in a state of ketosis. When eating in the following ratios, you starve your body of glycogen and replace it as a fuel source with ketone bodies:

The ratio of macronutrients on the keto diet is as follows: 

• High fat: 70-80% of daily calories
• Emphasis on healthy fats like avocado, olive oil, coconut oil, MCT oil, and full-fat organic dairy
• Moderate protein: 20-25% of daily calories
• Emphasis on grass-fed beef, pastured pork, chicken, and eggs, and wild fish
• Low carbohydrate: 5-10% of daily calories
• Emphasis on crucifers (kale, broccoli, cauliflower, Brussels sprouts), leafy greens, summer squash, and low-carb fruits like berries

Risk factors for this diet are minimal, but it's safe to expect some keto flu symptoms as you transition into this way of eating. Symptoms of keto flu (which is not an actual illness) include: 

• Muscle cramps and soreness
• Brain fog
• Exhaustion and fatigue
• Stomach cramps
• Headache

These symptoms can occur if your transition too quickly or if your body is particularly sensitive to the transition. They shouldn't last more than a week or so.

The Bulletproof Diet

The Bulletproof Diet, invented by entrepreneur Dave Asprey in 2014, is a variation upon the keto diet. It focuses on a cyclical keto diet approach, which basically involves eating keto 5-6 days a week and then taking a day or two do include more starchy carbohydrates and replenish glycogen stores. This meal plan accomplishes the same goals as the keto diet while emphasizing particular foods rather than focusing on food groups (although target macros are the same as the keto diet on non-carb days). 

Taking a color-coded approach, the Bulletproof Diet categorizes foods as green, yellow, or red. There are foods in each color category in all of the food groups, so not all fats are green, for example. The goal of the low-carbohydrate diet is not only to get you eating more healthy fats, it's also to emphasize whole foods and discourage eating processed foods. That being said, there are a number of Bulletproof products that are sold alongside this eating plan. Buying them isn't required to do well on this diet, but it's a pretty hard sell. 

The upside to this plan (along with other cyclical keto diets that don't have this branding) is that you might reduce your risk of getting the keto flu by giving yourself more starchy carbs once a week. There isn't a lot of science to back up this idea, and everyone responds to dramatic carb reduction differently. 

The Scandanavian Low-Carb, High-Fat Diet

This diet, outlined by Sten Sture Skaldema, who wrote the book Lose Weight by Eating, also takes a similar approach to eating as the keto diet. Without focusing on specific macro ratios, this diet encourages eating healthy fats and discourages most carbs. 

Although it's more lax on macro measurements than the keto diet, this diet restricts all fruit intake. Other than that, it's quite similar to a keto approach, tapping into your body's fat stores for energy and shifting your metabolism away from using glucose.

Should You Try a LC-HF Diet? 

LCHF diets are a hot topic for debate among medical experts and nutritionists. For decades, low-fat, high carbohydrate diets were touted as the key to health, but in recent years, a scandal involving research paid for by the sugar lobby removed credibility from the standard nutrition advice, which was to avoid fats, especially saturated fat, in favor of carbohydrates.

While researchers have been rethinking this misinformation, the keto diet and LCHF diets like it have been popping up and gaining popularity. Saturated fats like coconut oil and dairy fat are no longer demonized, while low-fat diets are going the way of the dinosaur. While these new diet trends are easy to learn about, it might not be as easy to find out whether or not this approach is right for you, specifically.

Keto for Women

A study came out earlier this year testing the efficacy of a LCHF diet on both male and female mice. It revealed a pretty dramatic difference in weight loss. In fact, after 14 days on the diet, the male mice lost weight, while the female mice not only gained weight, but their blood sugar markers declined, rather than improved. While there are a number of guesses as to why this happened, many women's health experts believe that estrogen levels have something to do with these results.

Conversely, Dr. Anna Cabeca, an OBGYN who works with peri- and post-menopausal women, seems to have consistently positive results on the keto diet for her patients. This difference in reported findings supports the idea that estrogen has something to do with the difference in efficacy. Other factors, including women's greater sensitivity to dramatic dietary changes, hormonal disruption, and an increase in cortisol, could also play a role in the differences between men and women on a LCHF diet.

This isn't to say that fertile women won't ever have success on the keto diet, but it's worth noting that if you find that you're not losing weight/body fat or getting the health benefits you were expecting, this could be why. Most keto experts recommend that women ramp up more slowly to avoid the stress of the keto flu, in addition to increasing protein intake to avoid the loss of lean muscle mass.

Alternative Approaches to LCHF Diets

It's possible to eat a low-carbohydrate diet without eating high-fat. There are a number of dietary approaches that address weight loss through the restriction of carbohydrate intake without emphasizing a high fat intake. 

These diets include the Atkins Diet (in all its forms), the South Beach Diet, the Zone Diet, the Slow Carb Diet, the Dukan Diet, and many others. The majority of these diets place a greater focus on carb reduction and healthy protein intake than on fats. In fact, some of these diets are low-fat in nature. 

While the jury is still out on which diet is the most likely to reduce your risk of high blood pressure, high cholesterol levels, high blood sugar, and obesity, there's research to support that nearly every diet we've mentioned so far is better for your health than the standard American diet. 

Getting started on a LC-HF Keto Diet

Now that you've had a chance to read through the various options in this category of eating plans, the next step is to get started. Starting can sometimes be the biggest challenge, which is why we've created a Quick Start Guide and a 5-Day Meal Plan to help hit the ground running. These resources include recipes, shopping lists, and quick tips to help you overcome the challenges at the beginning. 

As always, if you're starting a plan like this for the first time, it's important to check with your doctor to find out whether or not this plan is right for you, based on your own medical history and personal goals.