Staying Keto: What Happens After A Cheat Day?

If you fall off the keto diet for a day, you will likely experience a spike in your blood sugar levels, which can cause a sugar crash, fatigue, irritability, and increased appetite and cravings. This can lead to weight gain and bloating. The time it takes to get back into ketosis varies from person to person but generally takes one to three days. It is important to note that reintroducing carbohydrates after being on a keto diet can be a shock to the body, and it is recommended to do it gradually and with the guidance of a healthcare professional.

You will fall out of fat-burning mode

If you're on the keto diet, you might be wondering if you can take a day off to enjoy your favourite carb-heavy foods. The short answer is yes, but it will throw you out of ketosis. Ketosis is when your body burns fat for energy instead of carbohydrates. Usually, our bodies run on glucose in the form of foods like flour, grains, vegetables, and fruit. But when you dramatically reduce your carb intake, your body is forced to burn stored fat instead.

When you introduce carbohydrates to your system, your body will use them for fuel instead of fat. This will be the case until you begin your keto regimen again.

The amount of time it takes to get back into that coveted fat-burning zone will vary based on the person, but it generally takes one to three days. If you’ve been restricting to a maximum—and then suddenly introduce carbs—it could take longer to get back into ketosis. Likewise, if you eat a lot of carbs on your day off, it may also take a little extra time.

How to Cheat on a Ketogenic Diet the Right Way

If you're going to go off your diet, it's much easier to stay on top of your overall nutrition and calories with cheat meals compared to entire keto cheat days. One large cheat meal can add 1,000 or more calories to your day, while a whole cheat day will add much more and potentially undo all of your hard work.

The best way to approach cheat days is by not cheating on your diet at all and splurging on keto-friendly substitutes to curb your cravings instead. You can find a ketogenic version of just about any popular meal to keep you on course.

Your blood sugar will spike

If you fall off the keto wagon for a day, you can expect your blood sugar to spike. This is because your body will switch back to using glucose as its primary source of fuel. When you're on a keto diet, your body is in a state of ketosis, which means it's burning fat for energy instead of carbohydrates. However, when you introduce carbohydrates back into your system, your body will preferentially use them for fuel.

This blood sugar spike can cause a range of symptoms, including jitteriness, mood changes, hyperactivity, and fatigue. It's important to note that everyone's metabolism is different, so the effects may vary from person to person. Additionally, the number of carbs needed to kick you out of ketosis can depend on the individual and how long they've been doing keto.

To minimize the negative side effects of this blood sugar spike, it's recommended to gradually transition out of ketosis over a two-week period. Choose carbohydrates that also contain protein and fiber, such as beans, as these foods take longer to digest and have less of an impact on your blood sugar levels. It's also important to stay hydrated, as dehydration can lead to a false sense of hunger and increased irritability.

During this transition period, it's best to avoid foods with more than four grams of added sugar, including naturally occurring sugars from fruits and honey. These foods can cause a sharp rise in blood sugar, triggering cravings and making it more challenging to stick to your diet.

To help burn excess carbohydrates and control weight gain, it's recommended to engage in physical activity. Aim for a minimum of 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity activity per week, along with at least two days of strength training.

Ketone production will stop

When you fall off the keto wagon for a day, your body will exit ketosis and stop producing ketones. Ketosis is a state in which your body burns fat for energy instead of carbohydrates, its preferred source of fuel. In ketosis, your liver uses fat to produce ketones, which are released into your bloodstream and used for energy. However, when you introduce carbohydrates back into your system, your body will switch back to using them as its primary fuel source, causing ketone production to halt.

During this time, your blood sugar will spike, providing an abundance of quick energy. Your body will use this readily available glucose for fuel until it runs out. At that point, ketone production will resume as your body switches back to burning fat for energy.

The number of carbs needed to knock you out of ketosis can vary depending on the individual and how long they have been on the keto diet. Generally, any high-carb meal exceeding your recommended daily carb limit will do the trick. For example, if your daily carb limit is 20 grams, a cheat meal containing 20 or more grams of carbohydrates will likely cause you to fall out of ketosis.

It's important to note that falling out of ketosis can lead to various side effects, including weight gain, bloating, increased appetite, cravings, fatigue, and irritability. Additionally, you may experience symptoms similar to the "keto flu," such as headaches, nausea, stomach pain, brain fog, and mood swings.

To minimize these negative side effects, it's recommended to gradually transition out of ketosis over a period of one to three days. This allows your body to adjust and helps reduce the impact on your blood sugar levels.

You may experience keto flu symptoms again

If you fall off the keto diet for a day, you may experience "keto flu" symptoms again. The "keto flu" is a common experience for people starting the keto diet, and it is characterised by a drastic lack of energy and fuzzy thinking. When you reintroduce carbohydrates back into your diet, you may experience these symptoms again, including headaches, nausea, fatigue, stomach pain, body aches, brain fog, and mood swings.

The severity of these symptoms will depend on your metabolism and the type of keto break you took. If you only had a small amount of carbohydrates, you may not experience any symptoms at all. However, if you ate a high-carb meal, you will likely fall out of ketosis and experience the keto flu again.

To minimise these negative side effects, it is recommended that you make a gradual transition back to a keto diet over a period of a few days to a week. Start by adding carbohydrates to one meal per day and slowly increase the amount and frequency over time. This will give your body time to adjust and reduce the severity of the keto flu symptoms.

Additionally, it is important to note that the longer you have been on the keto diet, the easier it will be to get back into ketosis. If you have been on keto for more than 3 to 6 weeks, your body is likely fat-adapted, and it will be much easier to return to ketosis quickly.

You might have blood sugar fluctuations

Quitting the keto diet can cause your blood sugar levels to fluctuate, which can lead to several unpleasant symptoms. When you stop following a keto diet, your body will switch back to using glucose as its primary source of fuel. This can cause a spike in your blood sugar levels, leading to an abundance of quick energy. However, this may be followed by a sugar crash, resulting in fatigue and irritability.

The severity of these blood sugar fluctuations will depend on various factors, such as how long you've been on the keto diet, your ketone levels, and your individual metabolism. Additionally, the amount of carbs you reintroduce and how quickly you do so will also impact your blood sugar levels.

To minimise the negative effects of blood sugar spikes and crashes, it is recommended to reintroduce carbs gradually. Start by adding carbs to one meal per day and see how your body responds. If things go well, you can slowly add carbs to more meals or snacks. This slow transition will help you avoid gastrointestinal distress and give your body time to adjust to the new fuel source.

It's important to note that blood sugar spikes can also be influenced by the types of carbs you consume. Opting for complex carbs, such as whole grains, fruits, and vegetables, will have a less dramatic impact on your blood sugar levels compared to refined carbs and sweets. Therefore, it's best to prioritise unprocessed carbs and aim for a balanced diet with a variety of nutrient-dense foods.

If you experience severe or persistent blood sugar fluctuations, it is recommended to consult with your doctor or a registered dietitian. They can provide personalised advice and help you navigate the transition out of the keto diet in a safe and healthy way.

Frequently asked questions