What is Keto Diet?
The keto diet (or ketogenic diet) is a very-low-carb diet, which can help you burn fat more efficiently. The keto diet prompts the body to produce fuel in the form of “ketones.” Your body burns ketones as an alternative fuel source for the body when blood sugar (glucose) is in short supply.
Keto diet involves drastically restricting carbohydrate intake, putting your body into a metabolic state called “ketosis.” When this happens, your body’s limited reserves of glucose starts to run out, and your body becomes incredibly efficient in burning fat for fuel. It turns fat into ketones in the liver, which can supply fuel to the brain. Simultaneously, the levels of fat-storing hormone insulin levels become very low.
The standard keto-diet is a very low-carb, moderate-protein, and high-fat diet that typically contains 75% fat, 20% protein, and only 5% carbs.
Health benefits of keto diets
Keto diet drives your body into a fat-burning mode. Simultaneously, the keto diet causes insulin – the fat-storing hormone – levels to drop (1,2,3). Fat-burning makes it easier for the body to lose weight, without experiencing hunger (4). Research shows that, compared to other diets, low-carb and keto diets result in more effective weight loss (5, 6).
On a keto diet, you’re likely to regain control over your appetite. When your body burns fat steadily, it has full access to weeks or months of stored energy, significantly reducing hunger pangs (4). It also facilitates intermittent fasting, something that can super-charge efforts to speed up weight loss, beyond the effect of keto only (7).
Control and reverse type 2 diabetes
Type 2 Diabetes is due to a change in metabolism, high blood sugar, and impaired insulin function. Keto diet helps control blood sugar levels and improves insulin sensitivity drastically in addition to fat loss, sometimes even leading to a complete reversal of the disease (8, 9).
Low-carb diets improve your risk factors for heart disease, including the cholesterol profile (HDL, triglycerides), while total cholesterol and LDL levels are moderately impacted (10).
Other important benefits
What to eat on a keto diet?
To remain in ketosis, restrict carb intake to under 50 grams per day, ideally below 20 grams. The fewer carbs, the more likely you achieve ketosis.
Keto diet foods that you should definitely try:
Unprocessed meats are low-carb and keto-friendly, and organic and grass-fed red meat might be even healthier.
But remember that keto is not a high-protein diet, so an average amount of meat is enough.
Excess protein is converted to glucose, making it harder t get into ketosis.
- Fish and seafood
Fatty fish (e.g., salmon, trout, mackerel, tuna) are especially good. Wild-caught fish is probably the best.
However, avoid breading, as it contains carbs.
Buying organic, pastured or omega-3 whole eggs might be the healthiest option.
To prevent high cholesterol, eat no more than 36 eggs, per day.
- A natural fat, high-fat condiments or oils
You should get a majority of your calories from plant-derived oil. For example, add coconut oil for cooking, and add plenty of olive oil to salads.
Remember, don’t fear fat. On keto, fat is your friend.
Examples of healthy oil:
- Vegetables growing above ground
Favorites include zucchini, avocado, broccoli, cauliflower, and cabbage.
Fry them in butter or plant-derived oil and pour plenty of olive oil on your salad.
- High-fat dairy
Butter is good, unprocessed high-fat cheese (e.g., cheddar, mozzarella) is excellent, and high-fat yogurts is ok in moderation. Heavy cream is good for cooking.
Avoid drinking milk as one glass of milk equals 15 grams of carbs. But you can use milk sparingly in your coffee.
Avoid low-fat yogurts because they often contain lots of added sugars.
- Nuts and seeds
Take nuts and seeds in moderation.
Also, beware that cashews are the relatively high carb. Choose macadamia or pecan nuts instead.
Some examples of nuts and seeds that you can eat:
What to drink on a keto diet?
The #1 option. If you experience a headache or symptoms of “keto flu,” add a few pinches of salt to your water.
- Bulletproof coffee
Take coffee without sugar. You may add some milk or cream.
For extra fuel from fat, stir in butter and MCT oil. The fat provides satiety and helps curb cravings. Start with a teaspoon – some people experience stomach discomfort if adding too much fat at once.
Feel free to drink most teas. Don’t add sugar.
- Bone Broth
Try to avoid
Avoid carb foods containing a lot of sugar and starch, including wheat-based products, pasta, rice,and cereal. Also, avoid processed foods.
Furthermore, avoid foods that are incredibly high in protein.
Avoid low-fat diet products. Sugar-free products are also off-limits because they are high in sugar alcohols, which might affect ketone levels.
Avoid fruits (except berries), beans, root vegetables, and legumes.
Also, avoid unhealthy fats.
Alcohol on keto: yea or nay?
Unlike most diets, which usually bans alcohol, the keto diet allows moderate consumption of specific alcoholic beverages. Nevertheless, be aware that alcohol consumption disrupts ketone production because alcohol slows fat burning.
You may drink dry red and white wine in moderation. Spirits – like gin, vodka or whiskey – have no carbs at all.
Beer is generally not ok – it is liquid bread – but low-carb beers are OK if you drink only occasionally.
Are you in ketosis?
To get into ketosis, restrict to preferably20 net carbs per day. Add exercise to increase ketone levels and speed up weight loss.
If you are in ketosis, you may experience the following symptoms:
- Dry mouth and increased thirst
Unless you drink enough and have sufficient electrolytes (salt), your mouth may feel dry.
Drink a cup of bouillon or two daily. Drink as much water as you need.
- Frequent urination
In addition to frequent urination, you may excrete acetoacetate (a ketone body) via the urine. The acetoacetate levels can be measured using urine strips.
- Keto breath
Keto breath is due to a ketone body, acetone, escaping via our breath. It gives a “fruity” smell, or similar to nail polish remover.
How to measure ketosis?
These are the most common ketone measuring tools:
- Urine strips
Urine strips are the first option for most beginners on a keto diet. It is the simplest and cheapest way to measure ketosis.
When you dip the strip in your urine, the resulting color change represents the presence of ketones. If you get a high reading (dark purple color), you’re in ketosis.
PRO: Readily available on Amazon. Very cheap and reliable.
CON: Results fluctuate depending on how much fluid you drink. And as your body adapts to a keto diet, you reabsorb ketones from the urine, making the urine strips less reliable even if you’re in ketosis.
- Breath ketone meters
Breath analyzers detect the general ketone level in your breath and report the results in color code. At $150 and up, they are more expensive than urine strips but cheaper than blood-ketone meters in the long-term because they are reusable.
You can hook it up to a computer or smartphone and get a more accurate analysis via the app.
PRO: Simple and reusable
CON: Does not provide a very accurate reading of blood ketones and can be misleading. More expensive than urine strips, and a higher upfront cost than a blood meter.
- Blood-ketone meters
Blood-ketone meters show an exact and real-time level of ketones in your blood. They are the gold standard for ketone measurement.
PRO: Accurate, reliable
CON: Relatively expensive (at least $1 per test). You need to prick your fingertip for a drop of blood.
Blood ketone testing is an accurate method for measuring your ketone levels. With blood glucose test kits such as Keto-Mojo, you can measure your ketone levels in 10 seconds.
How to reach optimal ketosis
You can be in different stages of ketosis. The chart below demonstrates the values when testing blood ketone levels.
- Below 0.5 mmol/l: Not considered “ketosis.”
- Between 0.5-1.5 mmol/l: Light nutritional ketosis.
- 1.5-3 mmol/l: optimal ketosis (recommended for maximum fat burning, weight loss, and mental performance)
- Over three mmol/l: Higher than necessary; might indicate that you’re not getting enough food (“starvation”). In type 1 diabetics, it might be due to a severe lack of insulin.
- Over 8-10 mmol/l: Might be caused by a severe lack of insulin. Ketoacidosis may be fatal and requires urgent medical attention.
Potential side effects of keto diet
As you start preferentially burning fat and ketones, you may experience some side effects, especially within the initial week.
Keto flu is common at the beginning phase of a keto diet. These are the symptoms that you may experience a few days after you start a keto diet
- A headache
- Light nausea
- Lack of motivation
- Brain fog (difficulty focusing)
These symptoms usually dissipate within a week, as your body adapts to ketosis.
The primary cause of keto flu is that carb-rich foods can cause water retention in your body. When you start a keto diet, you lose much of the retained fluid.
You can reduce symptoms of keto flu by making sure you have sufficient intake of water and salt. Drink a cup of bone broth or bouillon, 1-2 times per day.
Other common side effects of keto diet
- Leg cramp
- “keto breath”
- heart palpitation
- reduced physical performance
- reduced alcohol tolerance
Who should NOT do the keto diet?
Keto diet is safe for most people (13). However, you should take special precaution if you:
- Take medication for diabetes
- You may need to lower insulin doses significantly.
- You need to test your blood sugar frequently.
- Take medication for high blood pressure
- There is a risk of getting low blood pressure relatively quickly.
- If your blood pressure is high despite combining the keto diet with medication, you should NOT take extra bouillon or salt.
- Choose a more moderate low-carb diet, with at least 50 grams of carbs per day
While the keto diet has many proven benefits, it’s still controversial. The main potential danger regards medication, e.g., for diabetes, where doses may need to be adapted.
The Bottom Line
Keto diet is an excellent diet but not for everyone. Keto diet is especially ideal for those who are obese or diabetic.
It may be less suitable for those who are breastfeeding or have a chronic disease.
And, as with any other diet, it will only work if you are consistent and stick with it long term.