If you’re looking to lose weight and improve your health, you may have heard of the keto diet and intermittent fasting.
Both of these diets have been shown to help people lose weight and feel better about their health.
What if you want to try both, though?
Can you do both keto and intermittent fasting at the same time?
Intermittent Fasting And Keto
First, let’s be clear about what each diet is. One of the most popular diets right now is the ketogenic diet, and for good reason.
It has been shown that this low-carb, high-fat diet helps people lose weight quickly and successfully.
Even though it seems odd, it can also help to lower “bad” cholesterol and raise “good” cholesterol.
It can lower the fat globules in the blood called triglycerides, lower the amount of sugar in the blood, and make insulin resistance better.
This makes diabetes less likely.
The keto diet can even help fight cancer because it stops cancer cells from getting their favourite “food,” which is glucose (1).
But what is the keto diet?
How does it work?
The keto diet is just a way of eating that helps your body get into a state called “ketosis.”
When your body is in ketosis, it burns ketones for energy instead of carbs.
Ketones are energy units that are made from fat (1).
This process not only helps you lose weight, but it’s also why the diet has the other benefits listed above.
There are a few things you should know before jumping on the keto trend.
On the keto diet, you can only eat a small amount of carbs, usually less than 50 grammes per day.
This can be hard for some people because carbs are in many healthy foods, like fruits, veggies, and whole grains.
So, we need these foods because they are full of vitamins and minerals, which help our immune systems and do a lot of other important things in the body.
Because of this, it is best to cut out the less healthy carbs.
These include sweets, cakes, cookies, and treats that have sugar in them, processed foods like breakfast cereals and chips, potatoes and potato products like fries, and white foods like bread, rice, and pasta.
Fat is a big part of the keto diet, making up about 55% of your daily calorie intake (2).
Even though this sounds unhealthy, it’s important to know that not all fats are the same.
Part of the keto diet is eating healthy fats, like those in eggs, nuts, olives, and olive oil.
Not everyone can do the keto diet.
Some people might get headaches, feel tired, or get cranky as a side effect (3).
Because of this, it can be hard to stay on the keto diet, but there are a lot of tools and recipes to help make the change easier.
Intermittent fasting is different from the keto diet because it doesn’t limit what you can eat.
Instead, it limits when you can eat.
So instead of eating three big meals and a few snacks every day, you eat two or three smaller meals in a shorter amount of time.
Intermittent fasting is just a way of eating that switches between times when you eat and times when you don’t.
Intermittent fasting can be done in a lot of different ways, but the most popular way is to not eat for 16 hours and then eat for 8 hours.
Some people do this every day, while others only do it a few times a week.
Like keto, intermittent fasting is also good for your body in a big way.
For one thing, it helps to keep your blood sugar levels stable (4) and stops insulin from going up too high.
Again, it can help put your body into ketosis, just like keto.
If you are on a diet, it makes sense that you want to burn fat because that is how you lose weight.
Intermittent fasting can sometimes help you get into ketosis, but not always.
If you want to get into ketosis by fasting every other day, there are a few things you should know.
First of all, it’s important to know that not all types of intermittent fasting will put your body into ketosis.
For instance, the 16:8 method, which was mentioned above, is not likely to lead to ketosis unless you also eat very few carbs.
On the other hand, longer fasts, such as 24-hour fasts, are more likely to put your body into ketosis (5).
Since the body isn’t getting any energy from food, it starts to use glycogen stores in the liver and muscles.
Before fat can be burned as fuel, all of the glycogen stores must be used up.
Because of this, it takes a longer fast for your body to be able to get energy from your love handles and belly fat.
A good way to lose weight is to follow an intermittent fasting plan that might start with a 24-hour fast and then switch to the keto diet. Even though it’s not easy, as we’ll see in a bit.
The keto diet teaches your body to burn fat for energy, which it will continue to do as long as you eat few carbs.
This is why intermittent fasting and the keto diet can work well together.
But once the body is getting energy from fat, if you eat a meal with carbs in it, the body will switch to getting energy from glucose.
One bad thing about irregular fasting is that it can make you hungry.
But this is yet another reason why the keto diet and irregular fasting work well together.
When you eat a lot of fat and protein, it takes your body a lot longer to break them down than when you eat processed carbs (6).
So you feel fuller for a much longer time and don’t get hungry as often.
Also, the keto diet raises the amount of the hormone leptin in the body (7).
This is good because leptin makes you feel less hungry (8).
Another bad thing about irregular fasting is that it makes you tired.
The keto diet can also help in this way because it has been shown to make mitochondria work better.
Our cells have tiny batteries called mitochondria.
They use the glucose or ketones that come into the cell to make energy (9).
Constipation is a bad side effect of intermittent fasting (10).
In the same way, the lack of fibre that you would normally get from veggies can also make you constipated (11).
Because of this, it’s important not to cut back on veggies just because they have carbs.
If you eat a lot of fibrous, leafy veggies, you’ll get enough fibre to keep you regular.
The best vegetables are broccoli, spinach, cabbage, and cauliflower.
Since cooking breaks down some of the fibre, it’s better for your digestive system to eat these veggies raw or just barely cooked (12).
Also, veggies with a lot of fibre keep the good bacteria in your gut healthy.
This is important because a high-fat diet can make ketones, which can lower the number of good bacteria in the gut (13).
Our immune system (14) and mental health (15) depend on the bacteria in our guts a lot.
Because of this, it’s important to eat fibrous veggies, not eat too much fat, and not follow a keto diet for too long.
It doesn’t help to be skinny if you are sick a lot and don’t feel good about yourself. Balance is everything.
The keto flu is a side effect of the keto diet that can be very bad.
This is an umbrella term for a group of conditions.
Some of these signs are headaches, feeling tired and cranky, feeling sick, and having trouble going to the toilet.
Even though it makes you tired, it can also make it hard to sleep (3).
Intermittent fasting can also make you irritable, tired (16), and have trouble sleeping.
To be clear, irregular fasting does not cause sleep problems in and of itself.
But since most people who do intermittent fasting skip breakfast, the biggest meal of the day is often in the evening.
If they haven’t eaten all day and are very hungry, they are more likely to eat too much or too close to bedtime.
Both can make you feel sick to your stomach, which can keep you from sleeping (17).
Since digestion slows down at night, it’s very important to wait at least three hours before going to bed after dinner (18).
This is especially important if you are also on the keto diet because fat and protein take longer to break down and digest (6).
Whether or not you are on a plan to lose weight, you should drink a lot of water.
All of your body’s processes depend on how well you stay hydrated.
If you drink a lot of fresh water, it helps keep your digestive system going and keeps you from getting constipated.
It also tells your brain that your stomach is full, which will help keep those hunger gremlins away. And you’ll probably eat less (19).
Even though intermittent fasting and a keto diet are good for you, it’s best to start slowly to reduce the effects of the side effects.
You can do this by starting with the keto diet and adding intermittent fasting or vice versa. You could also slowly stop eating carbs and only fast for twelve hours at first.
Just pay attention to your body and move slowly.
References
1) The Potential Health Benefits of the Ketogenic Diet: A Narrative Review https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8153354/
2) Ketogenic Diet https://www.ncbi.nlm.nih.gov/books/NBK499830/
3) What is keto flu? https://www.health.harvard.edu/blog/what-is-keto-flu-2018101815052
4) Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians https://clindiabetesendo.biomedcentral.com/articles/10.1186/s40842-020-00116-1
5) Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan https://www.cell.com/cell-metabolism/fulltext/S1550-4131(16)30250-9
6) How Long Does a Fatty Meal Take to Digest? https://www.livestrong.com/article/498950-how-long-does-a-fatty-meal-take-to-digest/
7) Hypothalamic Hormones and Metabolism https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3244537
8)Leptin signaling, adiposity, and energy balance https://pubmed.ncbi.nlm.nih.gov/12079865/
9) Ketogenic diet – a connection between mitochondria and diet https://www.drmyhill.co.uk/wiki/Ketogenic_diet_-_a_connection_between_mitochondria_and_diet
10) Health Effects of Alternate-Day Fasting in Adults: A Systematic Review and Meta-Analysis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7732631/
11) Definition & Facts for Constipation https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/definition-facts
12) Dietary fiber content of commonly fresh and cooked vegetables consumed in India https://bit.ly/3AUTqUN
13) Ketogenic Diets Alter the Gut Microbiome Resulting in Decreased Intestinal Th17 Cells https://www.cell.com/cell/fulltext/S0092-8674(20)30490-6
14) A healthy microbiome builds a strong immune system that could help defeat COVID-19 https://www.umassmed.edu/news/news-archives/2021/01/a-healthy-microbiome-builds-a-strong-immune-system-that-could-help-defeat-covid-19/
15) Gut microbiota’s effect on mental health: The gut-brain axis https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641835/
16) Potential Benefits and Harms of Intermittent Energy Restriction and Intermittent Fasting Amongst Obese, Overweight and Normal Weight Subjects—A Narrative Review of Human and Animal Evidence https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371748/
17) Does the Proximity of Meals to Bedtime Influence the Sleep of Young Adults? A Cross-Sectional Survey of University Students https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7215804/
18) Aspects of sleep effects on the digestive tract https://pubmed.ncbi.nlm.nih.gov/12184167/
19) Seven health Benefits of Water Backed by Scientific Research https://www.everydayhealth.com/water-health/water-body-health.aspx
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