First came fat phobia. Fat was was thought to be the culprit of weight gain and cardiovascular disease -- partially due to old clinical trials suggesting that dietary fat increased the risk of heart disease. Low-fat diets were all the craze. 

People began cutting all fat out of their diets and replacing it with high-carbohydrate foods. You couldn't shop for groceries without seeing "low-fat" or "reduced fat" products. The problem was that the food manufacturers replaced the fat with processed ingredients such as sugar and salt to make a palatable product.   

Recent reviews have since debunked the severity of all dietary fat. The American Heart Association released a statement claiming that fat is not necessarily the culprit of chronic disease and in fact some healthy fats can actually improve cholesterol levels, lowering LDL cholesterol (the bad kind). The pendulum swung the opposite direction.

Low-carb, high-fat popularity 

Diets low in carbohydrates and high in fats have now become increasingly popular as a means for people to lose weight quickly. 

By now, most of you are probably familiar with the Atkins Diet, which dates back as early as 1958, but further variations on this low-carb theme have stepped into the limelight in recent years. 

You may be more familiar with the term ketogenic diet, which is a very low-carb, high-fat diet. The goal of the ketogenic diet is to starve your body and brain of carbohydrate based fuel, and replace it with fat. When your body doesn't have enough available blood glucose for fuel, fatty acids will be broken down and converted into ketone bodies, or simply ketones.

The Ketogenic diet has great application in the field of medicine, being of particular relevance and benefit to diabetic and epileptic patients.


It’s important to consider that just because a diet is low-carb, doesn’t mean that it’s healthy. By the technical definition, you could be on a “low-carb diet”, while still eating processed foods such as cakes, cookies and sweets. This is why it’s important to consider both the macronutrient percentage ratio and the type of foods you’re eating. 

When it comes to carbs, focus on the complex ones that are high in fiber (whole grains, whole wheat, brown rice, quinoa, oatmeal, fruits and vegetables, legumes). Your body takes longer to digest these complex carbohydrates, giving you reduced cravings, especially when you combine them with healthy fat and protein sources. 

Keep in mind that low-carb or keto diets may not be suitable for everyone and may present some risk factors. It's essential to consult a medical professional or practitioner before embarking on any drastic change to your diet. 


The Dietary Guidelines for Americans recommends that the average, healthy adult get 50 to 65% of their total daily calories from carbohydrate, with the rest from protein and fat. Anything less than this recommended range is considered to be “low-carb”. 


The definition for low-carb is a bit vague, as it technically is any amount lower than 45%. Most studies define it as less than 30% of carbs per your total calorie intake each day. 


On a keto diet, you’re only allowed to have 5 to 10% of your total calories come from carbs. This is considered a very low carbohydrate diet. When you calculate your carb intake on a keto diet, you can subtract indigestible carbs (fiber) from the total amount of carbs. This will give you your net carbs. 

The keto diet can also be classified by the grams of carbohydrates you have per day - not eating more than 20 to 30 grams. The keto diet also has a limit on protein (about 20-25% of calories) because too much protein can knock you out of ketosis. Fat intake for the keto diet is about 70-75% calories from fat. 


If you’d like to get an idea of how many grams of carbs you need on each of the above diets, simply multiply your total calorie intake by the percentage of carbs: 

For instance, say you eat 2,000 calories per day and want to follow a low-carb diet at 30% carbs per day:

2,000 x .30 = 600 carb calories per day 

For grams, divide that number by 4 (there are 4 calories per gram of carbohydrate)* 

600 carb calories / 4 = 150 grams carbohydrates per day 

*To calculate grams of protein and fat, divide by: 4 calories per gram of protein and 9 calories per gram for fat.


Now let's dive into why this diet has gained so much popularity and why so many people are ditching carb foods for their high fat counterparts.


A low-carb, high-fat diet isn't necessarily classified as being a ketogenic diet, nor does it need to be in order to be considered useful or successful. Let’s delve a little deeper to see if a low-carb, high-fat diet is the right choice for you.

When the typical sedentary person consumes more carbohydrates than are required for normal functioning, it's broken down into glucose (blood sugar) in the intestines before entering the bloodstream. This results in a release of insulin. 

Insulin acts like a shuttle, driving nutrients and energy into various tissues and cells throughout the body. Insulin is released with the ingestion of food and carbohydrates. 

Insulin is an important hormone, with many functions in your body. When it's functioning well, you're getting the right balance of blood sugar and energy to meet your needs. But too much of it over time, can lead to weight gain, especially in your tummy area. Quality of your diet and various lifestyle factors, such as activity, can influence insulin secretion and blood sugar management. 

Say you had a really sweet treat or a soda. You're blood sugar would spike, then inulin would come in to bring that sugar into your cells. When too much insulin is released it leads to a sudden drop off in blood sugar levels, leading to uncontrollable cravings and the all-too famous ‘sugar crash.’

As this blood sugar and insulin roller coaster ride, occur more and more, the body stores more fat and insulin resistance develops -- your cells get flooded with too much insulin and "shut down" to it's action. Your cells become less receptive to the effects of insulin, causing your body to release more and more insulin over time, and potentially leading to type 2 diabetes.

The low-carb component of a low-carb, high-fat, ketogenic, or Bulletproof diet is an effective way to keep insulin levels low. The high-fat aspect of the diet also encourages your body to switch to burning fat for its primary fuel source -- this means not only the fat you consume in your diet, but your stored body fat as well.

In a hurry? Skip ahead to actionable tips, tricks, and recommended supplements to help you succeed.


Is the low-carb dieting lifestyle right for you? Find out in this short, free assessment.

Low-carb, high-fat diets offer a range of health benefits: 

  • Decreased potential for fat storage, particularly visceral fat, known as ‘heart attack’ fat, which surrounds the organs in the abdominal cavity

  • Increased potential for fat utilization, possibly leading to weight loss and muscle gain

  • Decreased inflammation when the focus is on a large intake of healthy anti-inflammatory fats and the reduction of potentially inflammatory foods containing processed carbs and sugars

  • Decreased appetite due to slower digestion of dietary fat and the appetite-suppressing effects of protein

  • Improved blood markers such as high-density lipoproteins (HDL) and low-density lipoproteins (LDL), triglycerides, and glucose

  • Possible reduction in blood pressure

  • Possible implications for sufferers of type 2 diabetes, epilepsy, Alzheimer’s Disease, and Parkinson’s Disease

If you try a low-carb, high-fat diet, you may enjoy one, some, or all of these benefits. But nevertheless, there are some people who don't respond well to this type of dieting, so next we’re going to look at the disadvantages of low-carb dieting before taking a closer look at whether or not this is the right approach for you.


Before jumping into a new diet plan, it's essential that you know what you’re getting yourself into. Low-carb diets have become wildly popular, but before making the decision to switch over, it's important to think about the potential downsides. 

During the first seven to ten days of removing carbohydrates from your diet, your energy levels are likely to significantly drop. This is typically referred to as the adaptation phase, which simply means that your body needs time to produce the enzymes and other chemicals required to start using fat as its primary fuel source.

The adaptation phase is the hardest step, but an important beginning of a low-carb diet. 

BONUS: Breeze through the adaptation phase easier and faster than ever.

During this adaptation phase you may experience brain fog, lethargy, headaches, trouble sleeping, bad breath, and a feeling of heaviness throughout your body. Some of these sensations can be pretty unpleasant or uncomfortable. If you stick to it you’ll be out of the woods in a week or two. 

It's also common to experience low-level dehydration and increased thirst. This is likely because one gram of carbohydrate typically carries three grams of water along with it. By removing carbs from your diet you'll naturally drop a lot of water weight right off the bat. Keep in mind this isn't necessarily body weight and it's important to stay hydrated with lots of water throughout the day.

The adaptation phase is short-lived, although another main challenge is sticking to the diet and passing up on the many tempting sugary and carbohydrate-rich foods that are normal in the Western diet.

Related: Is The Keto Flu A Real Thing?

Eating out with friends, enjoying family meals, and grabbing a quick snack are all luxuries that we take for granted, and you'll likely begin to realize very early on, that these kinds of events aren’t always low-carb-friendly.

With a little forethought, preparation, and patience, you'll soon learn the tricks of the trade or ketogenic ‘hacks’ to really help you get the most out of not just your diet, but your life as a whole.

Jump ahead to tips, tricks, and supplements for a successful low-carb transition.


As we’ve seen already, low carb high fat dieting isn’t for everyone and some side effects may make the diet not worth it for you. Optimal carbohydrate intake can vary depending on your age, gender, activity, and medical or health status. 

Here are some questions to ask yourself before beginning a low-carb diet; these should help to clarify if it's the right choice for you:


If you are an experienced, hard-training athlete then you're most likely already aware of what kind of dietary methods work for you. Athletes engaging in frequent, high-intensity training – not weekend warriors or casual gym goers – usually do best on a diet that contains 30 – 50% carbohydrates, maybe even higher for people like bodybuilders. 

While the low carb approach has become popular in Crossfit communities and other niches of the fitness community, this does not mean it is optimal or even healthy for you highly active folks. So take the time and apply the due diligence to determine which foods work best for you. Listen to your body and what makes you feel good in the long-term.  

To learn more about combining physical activity with a low-carb or ketogenic diet check out the fan favorite Ketone Episode of the Optimal Performance Podcast.


If so, what was your experience, and just how high was your carbohydrate intake? This is important to consider because if a high-carb diet left you feeling like a million bucks on a consistent basis and you haven’t gained excess body fat then low-carb might not be right for you. On the other hand, if eating a carbohydrates cause you to feel bloated, lethargic, foggy headed, and generally miserable then a low-carb high-fat diet might be the solution for you.


This is a difficult question to answer for some because ‘low-carb’ tends to be a relative term. Consider low-carb as no more than 30 – 50grams of carbs daily. After adjusting for the often unpleasant adaptation phase, does low-carb eating leave you feeling lazy, leaden, and lethargic, or do you feel warm, vibrant, mentally alert, and full of energy? If you’ve tried low-carb and high-carb without any success then a more moderate and balanced diet is probably the right choice for you.


You should always consult your doctor before beginning any extreme diet - such as a ketogenic diet – but if you suffer from insulin resistance or diabetes then you may benefit greatly from low-carb dieting. This is also true of obese people, who have impaired insulin management and dangerously high blood glucose. The vast majority of heavily overweight individuals see massive and immediate results from dramatically reducing their carbohydrate intake.


If you’re merely entertaining the idea of improving your health and wellbeing in a profound way then you should know that low-carb dieting isn’t easy for everyone, and the adaptation phase in particular can be enough to put some people off of the concept permanently. So, take your time, ensure you know what to expect, consult your medical practitioner, and you will be far more likely to succeed!


There are some clear cut Do’s and Don’t’s when it comes to which foods to eat on a low-carb high-fat diet.

Let’s start with the foods you'll want to eat on a regular basis:

  • Fatty cuts of meat are preferred to ensure you are consuming adequate dietary fat

  • Poultry such as chicken, turkey, duck

  • Beef

  • Lamb

  • Pork

  • Oily fish (salmon, mackerel, sardines)

  • Whole eggs

  • Healthy oils such as coconut, MCT oil, olive, avocado, macadamia

  • Real butter

  • Full-fat dairy 

  • Fatty cheese (beware of potential lactose or milk sugar content)

  • Minimally processed bacon


The following vegetables can be eaten somewhat freely because of their high fiber and low-carbohydrate content:

  • Cruciferous vegetables such as broccoli, cauliflower, cabbage, and Brussels sprouts

  • Leafy greens such as spinach, arugula, chard, and mustard greens

  • Asparagus

  • Eggplant

  • Zucchini

  • Cucumber

The following vegetables are acceptable but strict portion control should be practiced:

  • Onion limit to ½ medium onion per serving

  • Tomato limit to 1 or 2 tomatoes

  • Carrot limit to 1 small-to-medium carrot

  • Bell Peppers limit to ½ - 1 pepper

  • Mushrooms limit to a handful of white button mushrooms or equivalent

Starchy vegetables such as corn, potatoes, beets, peas, and squash should be avoided. 


When in doubt, simply type “carbs in [insert food]” into Google.

These are the foods that you'll absolutely want to avoid, either because they are unsuitable for low-carb dieting or because they are generally harmful to health:

  • Refined vegetable oils such as canola, safflower, soy, and corn

  • Margarine and other hydrogenated fats and oils

  • Starchy carbs such as wheat, potato, oatmeal, corn, rice, and so on

  • Fast food such as pizza, French fries, and ice cream

  • Fruit should generally be avoided with the exception of small amounts of low-sugar fruits like berries

  • Alcohol

  • Sugar, honey, maple syrup, corn syrup, and sauces



Carbs should be kept in the  20 – 30g range daily, with fibrous vegetables and leafy greens making up the bulk of that number. This means that most dairy products, with the exception of cream and fatty cheeses, are off the menu because of their lactose (milk sugar) content.

You'll also want to keep a watchful eye on the net carb content of everything from condiments and spice mixes to the cream in your morning coffee. You may initially be very surprised by just how many grams of sugar and carbohydrates are hidden in every day foods; a few grams here or there can really add up and keep you from achieving a state of ketosis.


While ketosis is not absolutely necessary for low-carb success, it certainly does go a long way for some people. For this reason, it's generally best to consume about 20-25% of calories from protein because too much protein can knock you out of ketosis. Fat intake should be the highest, at about 70-75% calories from fat. 

Suitable protein sources include meats like chicken, turkey, beef, lamb, pork, as well as whole eggs, minimally processed bacon, salmon and other oily fish, and just about anything that used to swim, fly, or walk the Earth! You can also supplement with whey protein (we recommend Natural Protein with Collagen to give your body all the immune support and tissue maintenance it needs while making this transition to your new diet).


We have already touched on the subject of vegetables but the importance of consuming ample fiber, fat-soluble vitamins, antioxidants, and so on really can’t be stressed enough.

The idea of eating bacon and eggs at every meal may sound appealing to some, but it's not a healthy and balanced diet. It's important to increase micronutrient intake from vegetables.

Suitable items include broccoli, cauliflower, spinach, arugula, eggplant, avocado. You may also want to add items such as sauerkraut and kim chi (check for low to no sugar options) to maintain gut health.


It can be very exciting when starting a new low-carb, high-fat diet; after all, who doesn’t want to douse their meals in olive oil or eat big juicy steaks every day? Just remember that these type of diets are best done in the short-term, until you reach your goal and that low-carbohydrate diets aren't for everyone. 

This is your body and you only get one; gorging on nothing but processed foods and neglecting healthy, balanced nutrition is a recipe for disaster and can lead to widespread inflammation and digestive issues.

Instead, respect your body, focus on the four pillars of nutrition, and ensure you are providing it with everything it needs to function optimally.

If you're still not sure whether the LCHF diet is right for you, take this short assessment to find out!

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