This article has been Fact-Checked by Kendall Kennedy MS, RD, RYT
There are many weight loss diets out there. One that’s rising in popularity is the ketogenic diet. Will it help you lose weight?
One of the first uses of the ketogenic diet was to help people with epilepsy. It turns out that the keto diet can also be great for losing weight.
Keto diet explained
Any diet that gets you into ketosis is a ketogenic diet. Ketosis is a state in which your body mainly uses fat as a fuel.
The way to do that is mainly by reducing carbohydrate and protein consumption enough.
Most ketogenic diet guidelines focus on a specific macronutrient ratio for the food you eat. Your macronutrient ratio is how many calories in your diet come from fats versus protein versus carbohydrates.
In general your daily calorie intake should consist of 70-80% fat, 5-10% carbohydrate, and 10-20% protein. Let’s say you are aiming for a 2000 calorie a day diet. This would mean consuming about 155-177 grams fat, 25-50 grams carbohydrate, and 50-100 grams protein.
In theory you could consume anything that adds up within that range on a ketogenic diet. In reality you might also want to focus on other aspects of a healthy diet like fiber, vitamin, and mineral intake.
Total carbs vs net carbs
Important to note is that there is a difference between total carbs and net carbs. Not all the food you eat gets absorbed into your body entirely.
There is a specific category of carbohydrates that does not get absorbed into your body called fiber. Fiber can offer many health benefits and it doesn’t kick you out of ketosis. For those reasons you might want to avoid counting fiber as carbohydrate intake.
Benefits of the ketogenic diet for weight loss
There are both benefits and downsides to the ketogenic diet for weight loss. Find out if this diet is right for you.
Different foods have a different impact on your hunger.
In general, protein and fat are more filling than carbohydrates. Because of this the ketogenic diet might help you with weight loss by reducing your appetite. This can automatically reduce the amount of calories you eat or at least make your weight loss journey more comfortable.
Carbohydrates also spike your blood sugar. After an increase in blood sugar a dip usually follows. This dip in blood sugar can make your body send hunger and craving signals. The dip in blood sugar can also cause an energy dip.
Low insulin levels
When your blood sugar rises, for example by eating food with a lot of carbohydrates, your body reacts by releasing insulin. Too much sugar in your blood would be bad for your health.
Low insulin levels might help you burn more fat and less muscle mass when losing weight. In the short term this would not make too much difference for weight loss but in the long term muscle is useful for losing weight.
Lower blood sugar and insulin levels are also associated with better health in general.
An important nutrient for weight loss is protein. Protein is essential for building and preserving muscle mass. Muscle helps you burn extra calories day in day out so it’s very useful if you’re looking to lose some pounds.
Protein also helps you feel fuller. Your body also burns more calories processing an amount of protein compared to processing the same amount of calories in fats or carbohydrates.
Less processed foods
One of the main reasons why people gain weight is because of eating too many processed foods and drinks high in carbohydrates.
These foods often contain a high amount of calories without filling you up. On top of that they contain all kinds of additives that may harm your body.
There are processed keto diet snacks too but avoiding the high amounts of carbohydrates is already a big step forward for most people.
Downsides of the ketogenic diet for weight loss
There are also some possible concerns with the ketogenic diet. You can avoid some of them by approaching the ketogenic diet in a healthier way.
No micronutrient guidelines
The first downside of the keto diet is that there are no guidelines around vitamins, minerals and fiber. It might also be close to impossible to eat enough micronutrients and stay into ketosis.
A lot of vitamins and minerals are mainly present in vegetables. Staying below 50 grams of carbs (even if it’s net carbs) may be difficult to combine with consuming enough vitamins and minerals from whole foods.
There are plenty of people who also remove almost all vegetables from their diet. This can lead to micronutrient deficiencies which can in turn have negative effects on short-term weight loss and health.
Initial period of discomfort
Your diet gets used to your current lifestyle in all kinds of ways.
Let’s say your body has used carbohydrates as its main fuel source for many years. In that case it might not be used to burning fat as energy source. When you switch to the ketogenic diet you might experience a period of feeling low energy.
You might also have a hard time not eating any carbohydrates for a while. Carbohydrate foods can be addictive to some extent.
Almost anytime you drastically change your diet you will have an upset stomach for a while.
Most of these factors will go away after a while. You might want to wait with switching to the ketogenic diet until you have a few days where nothing important is happening.
Still possible to gain weight
Being in ketosis doesn’t mean you can’t gain any weight.
You might have seen fat bombs recipes and other keto replacements high in calories. A surplus of calories will still make you gain weight, even if you’re on the ketogenic diet.
Possible risk of side effects
It’s hard to know exactly what the long-term effects of the ketogenic diet are. Partly because the ketogenic diet can be done in different ways.
There is a possibility that people who follow the keto diet have a higher risk of kidney stones, osteoporosis and they can have increased blood levels of uric acid which is a risk factor for gout.
This can possibly be because of certain vitamin and mineral deficiencies.
Why people see big keto results
You might have become interested in the ketogenic diet because of the big weight loss results and positive reviews from some people.
While this diet can be great for actual fat loss you have to keep in mind that weight loss is not always fat loss.
Eating carbohydrates can increase the amount of water you retain in your body. Once you use all the energy from carbohydrates in your body you will retain less water.
This results in an early kickstart in weight loss. It’s unlikely that this is actual fat loss. The weight loss will most likely slow down after this initial period.
How to lose weight healthily on the keto diet
Consume enough electrolytes: together with the water weight loss you can lose a lot of electrolytes (salt, potassium, magnesium) in the initial period. Make sure you get consume enough.
Consume enough micronutrients: people often skip out on vegetables on the keto diet. This can have negative side effects on your weight loss and health. Make sure you still consume enough vitamins and minerals. Preferably with whole foods, if necessary with supplements.
Choose better fat sources: the case on saturated fats is not closed. It’s not entirely clear if they are as bad as once thought. For now it might be smarter to focus on fat sources like fatty fish, avocado, olive oil and nuts.
Who should not do keto
Some groups of people should not try the ketogenic diet without medical supervision:
- People who are diabetic
- People who take medication
- Women who are pregnant or breastfeed
It’s almost always smart to talk to a doctor before making any drastic changes in your diet.
How effective is the keto diet for weight loss?
It’s not entirely clear just how effective the ketogenic diet is for weight loss compared to other diets.
There are studies that conclude that the ketogenic diet is more effective than a low carb diet or other weight loss diets (3, 4). More studies are needed to make any strong claims. The long term effects of the ketogenic diet are also still unknown.
That being said, you can definitely lose weight with the ketogenic diet. Removing processed foods high in carbohydrates from your life can be great for weight loss and your health.
You can also lose weight while eating carbohydrates.