Fasting And Keto: The Ultimate Weight Loss Combination?

Combining the ketogenic diet with intermittent fasting is likely safe for most people. However, it is extremely restrictive, and there is a lack of research on the effects of combining the two. While it may help you lose weight faster, it is not necessary to combine the two, and some people should avoid this combination.

Intermittent fasting and keto: a safe combination?

The ketogenic (keto) diet and intermittent fasting are two of the most popular health trends today. Both methods are used to lose weight and control certain health conditions. While both have solid research backing up their purported benefits, it is unclear whether combining the two is a good idea.

Intermittent fasting is an eating method that alternates between periods of fasting and normal eating. There are several ways to do it, including the popular 16/8 method, which involves eating during an eight-hour window and fasting for the remaining 16 hours of the day. Other methods include skipping breakfast, one meal a day (OMAD), alternate-day fasting, and the 5:2 method, which involves eating normally for five days and restricting calories for the remaining two days.

The keto diet is a high-fat, very low-carb way of eating. Carbohydrates are typically reduced to 20-50 grams per day, which forces the body to rely on fats for energy instead of glucose. This metabolic process is known as ketosis. The keto diet has been used to treat epilepsy and shows promise for other neurological disorders, such as Alzheimer's disease.

Potential Benefits of Combining Both

Combining keto and intermittent fasting may offer several benefits. Firstly, it may help the body reach ketosis faster. Intermittent fasting naturally shifts the body's fuel source from carbs to fats, which is the basis of the keto diet. Secondly, it may lead to increased fat loss. Intermittent fasting boosts metabolism and promotes the burning of stubborn fat stores. Additionally, it may improve metabolic flexibility, allowing the body to easily switch between burning sugar and ketones for energy.

Potential Risks and Considerations

While combining keto and intermittent fasting may be safe for most people, it is not suitable for everyone. Pregnant or breastfeeding women and those with a history of disordered eating should avoid intermittent fasting. People with certain health conditions, such as diabetes or heart disease, should consult a doctor before trying this combination. Additionally, this approach may be too restrictive and challenging to sustain for some individuals.

Sample Meal Plan

When combining keto and intermittent fasting, it is important to focus on nutrient-dense foods during the eating window. Here is a sample meal plan for a 16:8 intermittent fasting schedule:

9:00 am - Omelet with cheddar cheese and mushrooms, black coffee

1:00 pm - Avocado salad and a keto-friendly protein shake

5:00 pm - Air fryer chicken wings with broccoli and cheese

Combining keto and intermittent fasting may lead to accelerated weight loss and improved metabolic flexibility. However, it is important to consult a healthcare professional before starting any new diet, especially if you have a medical condition. Additionally, this combination may not be suitable for everyone due to its restrictive nature.

Pros and cons of each approach

Intermittent Fasting (IF)

Pros

• IF is a flexible approach with multiple versions, such as the 5:2 method, alternate-day fasting, and the popular 16/8 method.
• It is not as restrictive as keto and allows for a range of healthy and enjoyable foods.
• It does not require calorie counting.
• It may have long-term health benefits, including improved blood pressure, cardiovascular risk, cholesterol level, and inflammation biomarkers.
• It has been shown to reduce inflammation, help control blood sugar, and improve brain function.
• It can be an effective way to lose weight.

Cons

• Fasting is not for everyone.
• It is not recommended for people with diabetes, pregnant or breastfeeding women, or those under 18.
• It may be challenging for people who struggle with overeating or binge eating.
• The long-term health effects of IF have not been studied.
• Weight loss may come from the loss of muscle mass and not fat.

Keto Diet

Pros

• Keto is a quick-fix diet, and people tend to lose weight faster on this diet.
• People anecdotally feel less hungry following the keto diet than other restrictive diets.
• It allows for more meat-based protein and dairy-based fats.
• It may help burn stored body fat.
• It has been used for nearly a century to treat epilepsy and shows promise for other neurological disorders like Alzheimer's disease.
• It may reduce blood sugar, improve insulin resistance, and lower heart disease risk factors.

Cons

• There are concerns about the long-term risks of following the keto diet beyond six months.
• It is challenging to follow the ultra-restrictive guidelines.
• The diet requires cutting out grains, legumes, most fruits, milk, yogurt, and many types of vegetables.
• Keto's restrictions can cause vitamin and nutrient deficiencies if followed for longer than 3-6 months.
• Eating too much protein can interfere with ketosis and weight loss success.
• Side effects can include "keto flu", headaches, fatigue, bad breath, muscle cramps, nausea, and constipation.
• Keto dieting can result in cyclic weight loss and gain.

Combining IF and Keto

Pros

• Combining keto with IF may help the body reach ketosis faster, which may lead to additional weight loss.
• It intensifies the effects of the ketogenic diet, as both increase ketones in the blood.
• It may be a good option for people with type 2 diabetes or prediabetes.

Cons

• It is very difficult to maintain such a narrow way of eating.
• The combination may lead to double the side effects of each diet, such as nausea and constipation.
• It is not recommended for people with a history of disordered eating.
• It is not suitable for children, pregnant women, high-intensity athletes, or people with certain health conditions.

Sample menu for keto and intermittent fasting

Day 1

• 10 a.m.: Black coffee and scrambled eggs topped with avocado slices; water all morning
• 1 p.m.: Large leafy green salad topped with 2 tablespoons (tbsp) of olive oil, vinegar, and 3 ounces (oz) grilled salmon
• 3 p.m.: 1/4 cup macadamia nuts (optional)
• 5:30 p.m.: Chicken leg (with skin), 1/4 cup of cooked wild rice, and 2 cups of zucchini cooked with olive oil

Day 2

• 10 a.m.: Plain hot tea and a keto-friendly smoothie; water all morning
• 1 p.m.: 3 oz grilled chicken breast, half a plate filled with broccoli and cauliflower drizzled with 1 tbsp olive oil, and a whole avocado
• 3 p.m.: Unsweetened coconut chips (optional)
• 5:30 p.m.: 3 oz seared tuna cooked in olive oil on a bed of Asian coleslaw, topped with a drizzle of olive oil and sesame seeds

Day 3

• 10 a.m.: Black coffee with keto chia pudding; water all morning
• 1 p.m.: Three-egg omelet stuffed with half a pepper and spinach (1 cup) cooked in 1 tbsp olive oil, topped with half an avocado, and 1/2 cup sliced tomatoes on the side
• 3 p.m.: Olives (optional)
• 5:30 p.m.: Large kale salad (3 cups) with 3 oz shrimp drizzled with 2 tbsp of olive oil and vinegar of your choice

Potential health benefits of combining the two

Potential health benefits of combining keto and intermittent fasting

Combining keto and intermittent fasting may offer several health benefits, although it is important to note that there is limited research on the health effects of combining the two. Here are some potential benefits:

Reaching Ketosis Faster

Intermittent fasting may help your body reach ketosis quicker than the keto diet alone. During fasting, your body shifts its fuel source from carbohydrates to fats, which is the basis of the keto diet. As insulin levels and glycogen stores decrease during fasting, your body naturally starts burning fat for fuel. Therefore, adding intermittent fasting to a keto diet may help accelerate the process of reaching ketosis.

Increased Fat Loss

Combining keto and intermittent fasting may lead to greater fat loss compared to following a keto diet alone. Intermittent fasting boosts metabolism by promoting thermogenesis or heat production, causing your body to utilise stubborn fat stores. Several studies have shown that intermittent fasting can effectively reduce excess body fat. Additionally, intermittent fasting may preserve muscle mass and improve energy levels, which can be beneficial for keto dieters aiming to improve athletic performance and lose body fat.

Improved Weight Loss

The main benefit of combining keto and intermittent fasting is weight loss, as you are significantly reducing your calorie intake. This approach may be particularly beneficial for individuals with type 2 diabetes, as it can aid in weight loss and potentially lead to a reduction in medication. However, it is important to consult a healthcare professional before making any dietary changes, especially if you have pre-existing health conditions.

Improved Brain Function and Blood Sugar Control

Intermittent fasting has been shown to have additional health benefits, such as reducing inflammation, improving brain function, and enhancing blood sugar control. These benefits may complement the weight loss and metabolic effects of the keto diet.

Long-term weight loss maintenance

While the ketogenic (keto) diet and intermittent fasting (IF) are both popular weight loss methods, they are not easy to stick to. They are very restrictive, and there is a lack of research on the long-term effects of these diets, especially when combined.

Intermittent Fasting

Intermittent fasting is an eating pattern that involves rotating between periods of fasting and normal eating. It does not specify what to eat but rather when to eat. There are several ways to do it, including the 5:2 method, the 16/8 method, and alternate-day fasting.

Keto Diet

The keto diet, on the other hand, is a high-fat, very low-carb diet. It involves drastically reducing carbohydrate intake to 20-50 grams per day and replacing those calories with proteins and fats. This diet forces your body to rely on fats instead of glucose for energy, a state known as ketosis.

Combining the Two

Some experts say that combining the two approaches can be beneficial because they both increase ketone levels in the body. This may help accelerate weight loss and make the transition between fasting periods easier.

However, there is limited research on the combined approach, and it has not been proven effective for weight loss. Additionally, this combination may not be suitable for everyone and should be avoided by those with certain health conditions, such as chronic kidney disease, a history of eating disorders, or active cancer treatment.

Intermittent fasting has been shown to be effective for long-term weight loss maintenance. It offers flexibility and allows for a range of healthy and enjoyable foods. It also has potential long-term health benefits, such as improved blood pressure, cardiovascular risk, cholesterol levels, and inflammation biomarkers.

However, it is important to note that long-term (over five years) health effects of intermittent fasting have not been extensively studied. Additionally, weight loss may come from the loss of muscle mass rather than fat.

In contrast, there are concerns about the long-term risks of following the keto diet beyond six months. The ultra-restrictive nature of the keto diet makes it challenging to adhere to and maintain. It can also lead to vitamin and nutrient deficiencies if followed for longer than 3-6 months.

In conclusion, while combining keto and intermittent fasting may lead to initial weight loss, it is not a proven long-term solution. Intermittent fasting, when followed for an extended period, has shown more promising results for weight loss maintenance. However, as with any major lifestyle change, it is essential to consult your healthcare provider before starting any new diet plan.

Frequently asked questions