An egg fast, or “keto egg fast” is a short-term diet in which you consume eggs, butter, and other healthy fats.
Since it’s high-fat, moderate protein, and low-carb — a keto egg fast is one way to get into ketosis or maintain your ketogenic diet. A super-restrictive ketogenic diet, that is.
People are egg fasting, for the most part, to lose weight. Specifically, they’re egg fasting to push past stubborn weight loss plateaus, even if they’re already on a ketogenic diet.
But is an egg fast necessary? And can it really help you lose weight for the long-term? Get all that and more, including a sample meal plan, just in case you want to give a keto egg fast a try.
In 2010, the low-carb blogger Jimmy Moore made his month-long foray into egg-only dieting public — and the keto egg fast was born.
A keto egg fast is little more than an ultra restricted ketogenic diet.
From a macronutrient perspective, the egg fast and the keto diet are similar. You eat, by calories about:
- 60% fat
- 30% protein
- Under 10% carbs
The difference between the two diets is that on an egg fast, you get 100% of your calories from eggs, cheese, butter, and healthy oils.
So, why would you do this? Especially if you’re already in a fat-burning ketogenic state?
Proponents of the egg fast claim that it accelerates your fat burning capacity by restricting even more foods.
The theory is: when you only have eggs, butter, and cheese on the menu — you’re less likely to overeat.
Now then, on to the specifics of the keto egg fast.
The keto egg fast is not a very flexible diet. There’s a long list of rules and a short list of permitted foods.
The typical egg fast lasts less than a week, or around three to five days. This is, according to some folks, enough time to see impressive results.
On a keto egg fast, you eat:
- Whole eggs (at least six per day, preferably pasture-raised)
- Grass-fed butter or other healthy fats like coconut oil or olive oil (1 tablespoon per egg)
- Full fat cheese (up to 1 ounce per egg)
- Up to 3 cans of diet soda per day (optional)
Quick note: These are not Perfect Keto rules. And since diet soda consumption is linked to diabetes, metabolic syndrome, and heart disease — consider skipping it altogether[*].
Coffee and tea, since they’re sugar-free and don’t have calories, are allowed. But everything else with calories, including alcohol, is off-limits.
The remaining keto egg fast rules revolve around meal timing, such as:
- Eat an egg within 30 minutes of waking up
- Eat an egg-filled meal every three to five hours (don’t skip meals)
- Stop eating three hours before bed
If you want to try an egg fast, follow the above rules for three to five days. Any longer may lead to potential health risks (we’ll cover this later).
Do You Need to Be in Ketosis Before You Start?
Since an egg fast is a type of keto diet, being in ketosis before you start can make your life a lot easier.
It takes time (about four to six weeks) to adapt to using fat for energy. During this adaptation period, many people experience the keto flu — a catch-all term for insomnia, headaches, and brain fog that can accompany carb withdrawal.
Transitioning into ketosis with such a restrictive diet could be tough. Plus, it takes longer than three to five days for most people to get into ketosis.
A keto egg fast is a type of ketogenic diet, yet it’s distinctly more restrictive than most keto or low-carb diets.
A keto diet is a diet that keeps your blood sugar low and insulin production balanced — both necessary for ketone production. That means keeping carbs low — usually under about 20 grams per day or 5-10% of total calories.
A low-carb diet, however, is not necessarily a keto diet. You can, for instance, be lower-carb and still not get into ketosis.
Also, “low-carb” is not a standardized term. One recent study, for instance, put anyone under 40% calories from carbs into the “low-carb” bucket![*] And 40% of your calories from carbs is not low-carb; nor will it get you into a ketogenic state.
The carnivore diet consists of eating meat, dairy, fat, and fish. Assuming you’re eating enough healthy fats, the carnivore diet can definitely get you into ketosis. However, eating hundreds of grams of protein with no fat may lead to turning protein molecules into glucose — a process called gluconeogenesis.
Although gluconeogenesis doesn’t happen as often as some people claim, it is possible for too much protein and too little fat to kick you out of ketosis.
An egg fast is a highly restrictive keto diet that consists of plenty of protein and healthy fats and almost zero carbs. You’re likely to stay in ketosis on an egg fast and there’s little risk of triggering gluconeogenesis.
There isn’t any science on the keto egg fast, but nonetheless, people have reported a variety of health benefits. These benefits, most likely, are due to getting into ketosis — something you can do without such a restrictive diet.
#1: Weight Loss
Many people opt for such a restrictive diet because they’ve hit a weight loss plateau. Because the egg fast is so restrictive, it’s likely that you’ll not only maintain a state of ketosis (which helps you lose weight), but you’ll also go into a caloric deficit.
A keto diet helps you lose more weight than calorie restriction alone[*][*]. And it can help you improve your metabolism and reduce cravings[*]. This is mostly due to keto’s ability to balance your blood sugar and insulin response.
#2: Reduced Cravings
Eating carbs puts your body on a blood sugar-insulin roller coaster that’s hard to get off of. Carbs also increas your hunger hormone, ghrelin, which tricks your body into thinking it’s hungry when it’s not.
Ketosis, on the other hand, helps reduce cravings, which also leads to weight loss. Keto reduces circulating ghrelin, so you know to stop eating when you’re actually full. It also lowers neuropeptide Y, a hunger-stimulating brain factor[*].
Ketosis also increases cholecystokinin, or CCK, which travels from your gut to brain, letting your brain know that you’ve had enough food. There are several hormonal mechanisms that drive this hunger management benefit
#3: Lower Blood Sugar and Insulin
In many cases, high blood sugar (hyperglycemia) is the direct result of a high-carb diet[*]. And when a high-carb diet persists long enough, insulin resistance can develop.
That’s when your cells stop listening to the hormone insulin. As a result, your cells stop moving glucose out of your blood and safely into your cells for fuel or storage.
Unfortunately, insulin resistance is a short hop to type 2 diabetes and other chronic diseases.
But eating keto (eggs included) helps keep blood sugar low. In fact, the keto diet has even shown promise for treating and reversing type 2 diabetes[*].
Most people are only going on an egg fast for three to five days. It’s unlikely you’ll experience vitamin or mineral deficiencies within such a short period.
Still, there are some risks to consider before going on an egg fast, especially if you’re planning on more than five days:
- Digestive issues: An egg fast lacks foods rich in fiber, and dietary fiber is a necessary component of gut health and the gut microbiome[*]. Restricting fiber may lead to constipation, diarrhea, or other stomach issues.
- Vitamin deficiency: Eggs are rich in choline, vitamin A, and some other essential nutrients, but they lack many others. For instance: on an egg fast, you’ll have difficulty getting enough folate because the best sources of folate are dark, leafy greens. Folate, by the way, is required for energy (ATP) production.
- Mineral deficiency: The minerals magnesium, molybdenum, copper, and potassium may be scarce on an egg fast. Consider supplementation, and be sure to salt your eggs to ensure adequate sodium intake.
- Medical conditions: Those with certain medical conditions (familial hypercholesterolemia, those with no gallbladder) may want to skip the egg fast. Definitely consult your doctor.
Not sure what to eat on a keto egg fast diet? Here are some ideas for breakfast, lunch, dinner, and in-between snacks.
3 Egg Fast Breakfast Ideas:
- 3-egg omelet with cheese cooked in butter
- Cream cheese pancake (made with eggs, cream cheese, and butter)
- Scrambled eggs with cheddar cheese
3 Egg Fast Lunch Ideas:
- Egg and cheese quiche
- 3 hard-boiled eggs slathered with butter with a side of cheese
- Easy keto egg salad
3 Egg Fast Dinner Ideas:
- 3 deviled eggs
- Cheese quiche
- Egg crepe cooked in healthy fat
3 Egg Fast Snack Ideas:
- Hard boiled egg
- String cheese
- High-fat cheese of your choosing
If this meal plan seems restrictive, that’s because it is restrictive. Hm. Is this egg diet really worth it?
The Takeaway: You Don’t Need An Egg Fast
A keto egg fast is a fairly extreme keto diet plan. Nuts, meat, and non-starchy veggies are eliminated, leaving only eggs, butter, cheese, and oil.
The problem is, you’ll miss out on foods that contain essential nutrients like folate, magnesium, potassium, iron, and dietary fiber. Eliminating these foods, even for a short time, could be less than optimal for your health.
And then there’s the social drawback. Unless you’re hitting a breakfast spot, eating out is pretty much impossible on an egg fast.
If you’ve hit a weight loss platue on the keto diet and you’re looking to drop some more weight, try intermittent fasting or restricting calories.
Your platue could also be due to hormone imbalance, stress, or lack of quality sleep. It’s unlikely that you’ll hurt yourself on an egg fast, but it also isn’t necessary if you’re following a healthy ketogenic diet.
Speak to your doctor first and remember, weight loss is about the long-game. Not fast, unsustainable fat loss.