Almost everyone will have heard of the Keto diet and its purported weight loss benefits. So if you’re wondering what Keto is all about, and whether it’s right for you, this Keto 101 guide is for you.
To put it simply, the Ketogenic diet is a low-carbohydrate, high-fat diet that aims to help people get into “ketosis” where they’re burning fat for fuel instead of carbs. Just by reducing carb intake to near nothing, most participants begin losing a rapid amount of weight quickly. This rapid weight loss has won this diet a legion of fans, but leaves the questions; is the weight loss fat, water or muscle? Is Keto diet sustainable? Is it healthy?
In this guide we’ll look at whether with the right approach, the Ketogenic diet can end up being a sustainable lifestyle choice and if it can yield results that go beyond weight loss. Here’s what you need to know about it.
What is Ketosis?
Once you enter the world of keto, the term "ketosis" is something you'll hear about a lot. Ketosis is a metabolic state where your body opts for fat as fuel instead of glucose. Your body enters this state when the levels of glucose (i.e., the amount of sugar in your bloodstream) is low.
Glucose is the preferred energy source for many cells in your body. Since carbs are converted into sugar, a higher-carb diet means you're running on glucose. When you eat a low-carb diet, your body has limited glucose, so it goes into ketosis to survive. You might need to eat <50 grams of carbs to reach ketosis, but most have to eat less than 20 grams per day to get there.
Part of the science comes from the insulin hormone reducing as you continue eating a low-carb diet. That triggers fatty acids to be released from fat stores in large amounts. Those fatty acids are then taken to your liver, where they're oxidized and turned into ketone bodies. Those molecules then provide energy for your body.
These same ketones can also pass the blood-brain barrier, which means they can provide energy for your brain cells, too, when glucose is absent.
One of the big dangers of the Keto diet, is Ketoacidosis. This is a potentially life threatening condition when dangerously toxic levels of acid in the blood is created from excessive ketones.
Please consult with your medical professional whether a Keto diet is right for you before starting.
How Long Does it take to get into Ketosis?
The amount of time it takes to start using fat as fuel and enter ketosis will vary as every individual is different. You first have to use up all the glucose in your bloodstream for the transition to start, which can be started during periods of fasting, like the intermittent fasting diet.
On average, it takes between 2 and 4 days of carb restriction to enter ketosis, but it could take a week or longer. It all depends on your daily carb intake along with your daily fat and protein intake alongside components such as age, exercise, and metabolism.
If you are starting keto when you previously ate a higher-carb diet, you'll likely find the transition into ketosis takes longer than those who are a low-to-moderate carb diet before starting keto. That's because you have more glycogen stores to deplete before your body starts the process of ketosis.
You'll be able to tell when you're in ketosis as there are many signs that come along with it. You can also get ketone test strips, which measure the amount of ketones in your urine to indicate if you're producing ketone bodies (a sign that you're in ketosis).
Symptoms of ketosis include:
- Bad breath: Full ketosis often leads to bad breath, which may have a fruity note.
- Weight loss: The rapid short-term weight loss associated with keto typically starts once you enter ketosis.
- Reduced appetite: Most people experience appetite reduction once they enter ketosis.
- Increased focus: While you may have "brain fog" immediately after staring keto, ketosis generally leads to better focus.
- Fatigue: While ketosis will soon mean more energy, you'll experience fatigue as you're making the switch from glucose to fat.
Digestive issues and insomnia may also accompany the transition into ketosis, but realize that most of these side effects are only short-term. Once your body adapts to using fat as fuel, you should soon feel your energy and performance returning to normal, along with your bathroom habits.
Losing Weight on Keto
The reason Keto has become so popular is the many success stories of people losing massive amounts of weight. It was first poplularized in the 1970’s by Dr Atkins and his eating plan, which is essentially a Keto diet in the early stages and introduces more carbs later on. But the Ketogenic diet was actually first established in 1921 by Russell Wilder to treat epilepsy in children. Since then countless studies have shown that ketogenic diets can lead to weight loss, even without counting calories.
In fact, one study found that those on the keto diet lost over 2 times the weight of people on a low-fat, calorie-restricted diet. Additionally, when eating keto, triglyceride and HDL cholesterol levels also show improvement.
In general, the keto diet is considered superior to low-fat diets overall for countless reasons, including the increased protein intake that comes along with the keto diet, which helps you feel fuller for longer (no reason to track calories).
is the weight loss fat?
So we know that the Ketogenic diet can result in weight (mass) loss, but is it water, fat or protein (muscle)?
One study found that although a Keto diet resulted in a mean weight loss of 466 grams per day, 61.2% was water, 35% fat, and 3.8% protein. This means fat in grams lost were 163g.
They then compared this to a “mixed diet” (traditional/moderate carb diet) which resulted in mean weight loss of 277grams per day, of which 37.1% was water, 59.5% was fat and 3.4% was protein. This means fat loss in grams were 164 grams.
So although 68% more mass was lost, the actual fat lost was almost identical with the difference being a larger water loss on the Ketogenic diet.
Other Benefits of Keto
Aside from weight loss, following a ketogenic diet offers many benefits, including the following.
- Reduced appetite
- Increased levels of "good" cholesterol
- Reduced blood sugar and insulin levels
- Reduced blood pressure
- Helps improve acne
- May protect brain function
- May reduce risk of certain cancers
Thanks to its ability to help reduce blood pressure, blood sugar, and insulin levels, the ketogenic diet is especially popular amongst diabetics and pre-diabetics.
How do you follow a Keto Diet?
In its simplest form, the ketogenic diet requires you to lower your carbs and up your fat and protein. However, there are several versions you can follow if you want to start a ketogenic diet.
Standard Ketogenic DietThe standard ketogenic diet involves a very low carb, moderate protein, and high fat diet with the typical ratio being 75% fat, 20% protein, and 5% carbs. Realize that the 5% carbs is the maximum, and you can cut your carbs to zero.
Cyclical Ketogenic DietThe cyclical ketogenic diet involves periods of "re-feeding" where you eat a higher carb diet for awhile. The schedule might look like five days of keto followed by two high-carb days per week.
Targeted Ketogenic DietA targeted ketogenic diet lets you add carbs around the time you workout. This can be effective if you participate in strenuous activity and feel like carbs are a must for short-term energy. You need to be sure you burn the carbs off, though, or you're not doing keto!
High-protein Ketogenic dietWhile very similar to the standard ketogenic diet, this version includes more protein. The ratio is generally 60% fat, 35% protein, and 5% carbs. Again, you can reduce your carbs to even less.
While only the Standard Ketogenic Diet and high-protein version of the ketogenic diet have been study extensively, targeted and cyclical ketogenic diets are often used by athletes and bodybuilders.
The difficulty with following a Keto diet is that it is highly restrictive, which means long term adherence is low. In addition to this, the longer term health effects have yet to be scientifically established.
What Foods Can You Eat?
For most people, the ketogenic diet represents a major shift in what they consume. In order to ensure you’re getting enough healthy fats and protein, here are foods you should be eating on keto.
Fish and shellfish are super keto-friendly. Fish like salmon are high in B vitamins along with selenium and potassium, yet they contain almost no carbs. However, shellfish other than shrimp do have carbs, so don't buy blindly! Mussels, for example, have 7 grams of carbs per 3.5-ounce serving.
Consider working 2 servings of fish into your diet each week and you'll also enjoy the benefits associated with fish consumption, like improved vision.
While starchy vegetables like potatoes will quickly get you in trouble on the keto diet, non-starchy vegetables are low in calories and low in carbs. They also have plenty of minerals and vitamin C. Also, vegetables that contain fiber are super good for you, so look for vegetables with high fiber and a low net/digestible carbohydrate count (total carbs minus fiber).
Another benefit? Vegetables also protect you against free radicals!
Nutritious and oh-so-delicious, cheese is a great addition to your keto diet. Lucky for you, all cheeses are high in fat and low in carbs! About one ounce of cheddar will give you just 1 gram of carbs, yet 7 grams of protein and 20% for your calcium RDI.
Note that all cheeses are also high in saturated fat, but it hasn't been connected to a higher risk of heart diseases. In fact, some studies suggest cheese may help prevent heart disease. Plus, cheese contains conjugated linoleum acid, which is liked to improved body composition and fat loss.
Incredibly healthy, about 3.5 ounces of avocado contains 9 grams of carbs, but 7 grams of fiber, making for 2 grams of net carbs. Avocados also contain countless vitamins and minerals, such as potassium, which can help make the transition into your keto lifestyle that much easier.
Avocados are even linked to improved cholesterol!
Meat and Poultry
Meta is a staple on any keto diet, and fresh meat and poultry products contain no carbs. They're also rich in minerals like potassium, zinc, and selenium and contain a lot of B vitamins.
Plus, they offer a source of high-quality protein, which can help preserve muscle mass when eating a low-carb diet.
Consider eggs your new super food. They are one of the most versatile and healthiest things you can consume, especially while on keto. A large egg contains under 1 gram of carb and 6 grams of protein, making it an ideal staple whether you're scrambling, boiling, or baking with them.
With its unique properties, coconut oil is a popular choice for the keto lifestyle. For starters, it contains MCTs (medium-chain triglycerides), which the liver absorbs directly to convert into ketones as a rapid energy source. Moreover, coconut oil has been linked to increased ketone levels in people with brain and nervous system disorders.
When it comes to the fat in coconut oil, the primary one is longer-chain fat known as lauric acid, which suggests that coconut oil can provide a sustained form of ketosis.
Cottage Cheese and Greek Yogurt
Looking to get in some probiotics? Reach for a high-protein Plain Greek yogurt or cottage cheese product. While they may have some carbs, they are still part of a healthy keto diet.
After all, 5 ounces of Greek yogurt offers 11 grams of protein and just 5 grams of carbs. The same amount of cottage cheese has 18 grams of proteins and 5 carbs. So, consider them a tasty keto snack!
Aside from being tasty, olive oil contains lots of oleic acid, which is a monounsaturated fat linking to lowered risk of heart disease. Extra Virgin Olive Oil (EVOO) also contains lots of phenols, a type of antioxidant that protect the heart from inflammation and declining artery function.
Being a pure fat, olive oil has no carbs and its the ideal base for your keto-friendly mayo and salad dressings. However, since it's not as stable as saturated fats at high temps, it's best for low-heat cooking or for adding after you cook, like as a drizzle on vegetables.
What Foods Can't You Eat?
It may seem tough, but even though the list of foods to avoid is pretty long (and probably includes a number of foods you eat regularly), the transition to keto will be easy if you plan your next grocery trip accordingly. Keep these things out of your house.
Why no grains? For one, they're filled with carbs! You should try to limit and avoid grains completely, but especially stay away from oatmeal, white grains, wheat grains, rye, sourdoughs, oats, flour & corn tortillas, corn, buckwheat, quinoa, sorghum, barley, and -- unfortunately -- rice.
Fruits may seem like a healthy snack, but just because they're natural doesn't make them low-carb! While good in moderation, most fruits have a high sugar level and that means high carbs. Your best bet? Opt for low-sugar fruits like blackberries, raspberries, strawberries, blueberries, and tomatoes. You can also enjoy olives and avocados.
However, avoid high-sugar fruits like oranges and tangerines along with pineapples, bananas, apples, pears, grapes, mangos, fruit juices, nectarines, and peaches. Dried fruits like mango, dates, and raisins are also high in sugar. With that in mind, you also need to avoid fruit smoothies and juices other than lemon or lime.
If you want to enjoy fruits as an occasional treat, go for fresh and look at sugar counts before purchasing. Avoid frozen fruit as it usually has extra sweetener (even in the form of fruit juice), equating to more carbs!
While non-starchy vegetables get the green light, there are certain high carb vegetables that you should limit your intake of. Generally, anything that grows below the ground should be avoided, including potatoes and sweet potatoes (along with yams).
Other vegetables to avoid include corn, peas, parsnips, artichoke, and cassava/yuca.
While beans and peas are high in protein, they're also high in carbs, which means they should be avoided on a keto diet except for rare dishes.
In particular, you should avoid chickpeas, lima beans, baked beans, pinto beans, black beans, lentils, green peas, kidney beans, black-eyed peas, lima beans, navy beans, and great northern beans.
Non-Cheese Dairy Product
Cheese is a delicious treat! However, condensed milk and most other milk products are a big no-no for those on a low-carb diet. Try to limit your dairy intake to no more than 3-4 ounces daily and stay away from fat-free and low-fat yogurt along with creamed cottage cheese.
Unfortunately, most of the beverages we enjoy are packed with sugar, but does that mean you’re limited to black coffee? If you’re a coffee lover, low-sugar creamers do exist, but you should look to avoid the following.
Sodas, sugary energy drinks, sugary sports drinks, vitamin water, and many sparkling waters all contain a ton of sugars (and, therefore, carbs). So, read the label and, if they are low in sugar, make sure it’s a sugar substitute that won’t raise your insulin levels.
Downsides To Keto
So, now that you know all there is to know about keto, let’s talk about the downsides. Like anything, the ketogenic diet isn’t perfect. For some people, it will work great. For others, not so much. Consider these aspects before making a decision for yourself.
Major Diet ChangeFor most people, switching to the keto lifestyle represents a major change in their diet where they have to cut out fruits, breads, and grains such as rice.
The keto flu:Many people who start the keto diet complain of flu-like symptoms, which have been dubbed the “keto flu.” These symptoms come while transitioning from glucose to fat. Once your glucose levels are depleted, it could take awhile for your body to adapt to your new fat-burning goals.
Reduced performance:While getting used to keto, you’re likely to experience reduced performance as your body makes the shift from glucose to fat. For those concerned with athletic performance Keto is unlikely to be the best diet for you simply because the body needs glucose during periods of high intensity. When there is no or little glucose available, you’ll have less energy during workouts, which means less intensity, and less volume. Over time this will result in less adaptation and less muscle creation. This can create a vicious circle as the less muscle created means less calories are required by the body, which can result in fat gain.
These aren’t the only potential downsides to keto as everybody is different, but they are some major things to consider.
Being such a restrictive diet, it is hard to maintain for the long term, but if you are looking to lose weight (mass) quickly the Keto diet is hard to beat.
Interested in pursuing the keto lifestyle for yourself? Ask your doctor about what’s right for you.