What is the keto diet?

Most diets work the same way – by limiting the amount of food you eat and creating a calorie deficit. This means the diet provides your body with fewer calories than it needs.  Faced with this fuel shortfall, your body starts using stored body fat for energy.  

Ketogenic diets limits the type of food you can eat. Carbohydrates (carbs for short) are off the menu. 

There are several versions of the keto diet, and some are stricter than others, but most versions of keto limit your carb consumption to 20-50 grams per day. The rest of your calories come from fat and protein. Carbs should account for no more than 5-10% of your daily calorie intake. 

Cutting carbs to this degree forces your body to use fat for fuel. Your body converts fat into ketones which is where the ketogenic diet gets its name. Ketones can then be used for energy in place of carbs or, more specifically, glucose. 

As an added benefit, cutting carbs from your diet also means lower levels of blood glucose and insulin. When you eat carbs, blood glucose and insulin levels soon rise. This creates an ideal environment for fat storage and weight gain. Cutting carbs from your diet primes your body for fat loss. 

Low carb diets are often thought of as new but, in reality, they have been around for close to a century. Keto was initially used to help treat a variety of neurological conditions such as epilepsy in children. 

In the 1920s, Robert Atkins, re-popularized a low carb diet with his New Atkins Revolution Diet.

Getting into ketosis and the keto flu 

Getting into ketosis is a simple process, but it can take time – anywhere from a few days to a few weeks. Your body stores carbs in the form of glycogen, which is stored glucose combined with water. 

Your body holds glycogen in your liver and your muscles. The amount of glycogen in your body depends on several factors, including the size of your muscles, how much carbohydrates you usually eat, and whether you exercise or not. 

When you initially cut your carb intake down to 20-50 grams, your body will start using your glycogen stores. As your glycogen stores are depleted, your body starts to use fat and ketones for fuel. This gradual transition is the leading cause of what most low-carb dieters call the keto flu. 

During your keto transition, many people experience flu like symptoms. It's not serious, but it can be unpleasant enough to put dieters off the ketogenic diet entirely. The good news is that it only lasts a few days. There are also several things you can do to prevent it or make it less uncomfortable. 

Proven strategies for beating the keto flu include drinking plenty of fluids and taking electrolytes. Exercise can also speed up glycogen depletion and help you get into ketosis faster. 

Once your body runs out of glycogen, it will make the switch to making and using ketones for energy and your keto flu symptoms will disappear. 

How do you know you are in ketosis? 

Once you are in ketosis, you should notice the following changes and benefits:

1. Your keto flu symptoms vanish – keto flu happens as your body makes the transition from using carbs for energy to using fat and ketones. Once that change occurs, you should notice a significant improvement in how you feel. 

2. Less hunger – your body contains a lot of fat and that fat is your primary source of ketones. Your hunger should vanish once you enter ketosis and high fat, moderate protein meals are very filling.

3. Ketone breath – when your body produces ketones in large amounts, you may notice that your breath becomes slightly fruity. That smell is acetone, a type of ketone. If you find this unpleasant, make sure you drink plenty of water.

4. Weight loss slows down – glycogen is glucose combined with water. For every gram of glucose you have in your body, there are 2-3 grams of water. In the initial stages of keto, most dieters lose a lot of weight very quickly. This is both gratifying and motivating, but a lot of this weight is water. As your body uses its glycogen, the accompanying water is released and excreted. 

5. More energy – once you are in ketosis, fat becomes your main source of energy. Carbs tend to cause a rapid increase in energy, followed by an equally quick drop. That's why, after eating a sugary snack, most people need another one a few hours after. Ketones provide a much more sustained source of energy, so not only do you feel good, you’ll experience fewer energy crashes during your day. 

6. Brain fog will lift – Ketones can cross the blood-brain barrier and, once you are in ketosis, your brain will have a new and improved source of energy to use instead of glucose. In short, your brain runs great on ketones! 

If you experience any the above, it’s a safe bet that you are entering or are already in ketosis. However, there are a few additional ways you can confirm your body is producing and running on ketones. 

How can you measure ketones? 

There is no need to rely on how you feel to confirm you are in ketosis. Here are three additional methods for detecting ketones:

Ketone strips – also known as keto strips or keto sticks, these are plastic strips that have a small, reactive pad that detects ketones in your urine. While they are cheap they are not accurate enough to see if you're in ketosis. They're made for diabetic ketoacidosis testing. 

Ketone breathalyzer – keto breathalyzers measure the concentration of acetone ketones in your breath. These are easy to use and non invasive but also not accurate enough for keto diet testing because they only measure acetone. 

Blood ketone meters – blood ketone meters are considered to be the gold standard for measuring ketones. They provide medical-level accuracy and real-time results. Get yours today.

While you might be able to feel where you are in ketosis, measuring your ketones will tell you for sure. Testing your ketone levels can provide you with the feedback to adjust your diet for better results. 

What foods can and can’t you eat on keto?

While you could just follow a ketogenic diet menu plan and eat what you are told, most dieters prefer more freedom. If you cut your carb intake to 20-50 grams per day, you are free to eat almost all other types of food. 

Because of this, and to help you avoid accidentally undermining your progress, here is a selective list of the foods you cannot eat on keto. 

• Bread
• Rice
• Pasta
• Potatoes 
• Oatmeal 
• Pastries 
• Jam, jelly, and fruit preserves 
• Breakfast cereals 
• Soda – diet soda should be okay 
• Sports and energy drinks 
• Blended, sweetened coffee drinks 
• Sweetened iced tea 
• Cookies and cakes 
• Non-light beer
• Cocktails
• Sweets, candy, and chocolate 
• Sugary desserts 
• Most fruits except low-sugar berries 
• Fruit juice 
• Regular milk 
• Condiments such as ketchup and barbeque sauce 
• All beans and legumes 
• Breaded meat and fish 
• Deli meats that may contain hidden carbs  

If you are ever in doubt as to whether a food is or isn't keto-friendly, use a nutrition app or google it. Also, remember that many low-carb keto-friendly foods contain some carbs. If you eat a lot of them, you could end up consuming more carbs than you realize. Track your daily carb intake to make sure you aren't consuming more than 20-50 grams of carbs per day. 

So, what does a typical day of keto eating look like? That’s a good question! Here is a sample menu to give you an idea of what sorts of meals you can expect on keto:

Breakfast – eggs, bacon, cheese, and spinach omelet 

Lunch – large salad with grilled chicken and avocado 

Dinner – Beef curry with vegetables and faux rice made from grated cauliflower

Going keto does mean giving up carbs, but it doesn't mean your meals have to be boring or repetitive. Rather than think about what you can't have on keto, think about all the delicious foods you can eat!