Many people see the ketogenic diet as a way to lose weight quickly, or a diet to cycle in and out of. Once you get used to eating a keto diet, is it healthy to stick with long-term?
The answer, based on the latest research, is that we are still learning about the long-term benefits and negatives of this high fat, low carb diet.
For some, following a ketogenic diet may be one of the most impactful ways to increase longevity and overall well-being. For others, it might be more beneficial to adopt a more moderate approach to a low-carb diet.
Here are some research-backed examples of what we know about the long-term effects of the keto diet, starting with the potential benefits of eating keto long-term.
Promotes Weight Loss and Maintenance
While many people think of weight loss as an issue of aesthetics, for people who are chronically overweight, health risks become much more serious.
Whether excess weight comes from genetics, environment, or a metabolic disorder, the side effects that can occur with being overweight range from uncomfortable to potentially life-threatening. Being overweight puts you at greater risk for multiple chronic illnesses, from cancer to type 2 diabetes (*).
Unlike most weight-loss diets, the ketogenic diet not only promotes weight loss, if you follow it long-term it also helps you sustain the weight you lose.
Research shows that when you consume a low-carb diet, the hormone ghrelin is decreased (*). Ghrelin, also known as your hunger hormone, tells your body that you need to eat more.
When this hormone is high, people tend to overeat and gain weight. When this hormone is low, on the other hand, they’re less interested in food. Over time, if you continue to eat low carb, this keeps your calories in check
In addition to keeping ghrelin low, there are a couple of other hypotheses as to why low-carb diets work so well for weight loss.
One line of reasoning is that fat and protein increase satiety, and produce less blood sugar fluctuations. Therefore, you aren’t a slave to the whims of your blood sugar and are less likely to give in to cravings for high carb or high sugar foods. This leads to reduced food intake, producing a calorie deficit, and a lower body weight (*).
Another hypothesis is that low-carb dieting may increase the amount of energy you expend daily — AKA your burn more calories (*). Some research shows that there may be up to a 300 calorie metabolic advantage of eating low-carb.
The combination of lower ghrelin, reduced blood sugar fluctuations, and a faster metabolism may be the reason that many people find that they can keep the weight off long-term, if they continue to eat low-carb.
Preserves Muscle Mass
Maintaining a healthy muscle mass is crucial for health and longevity, and can protect your body from chronic diseases.
You can think of your lean muscle mass as a reservoir of amino acids that your body can pull from in time of need. Amino acids not only serve as precursors to glucose but play a role in the maintenance of all your vital organs, including your heart, liver, and brain (*).
The research is mixed on the topic of eating keto and preserving muscle mass.
Some sources argue that when glucose is low, your body will turn to muscle tissue as a source of energy. One recent study confirmed this theory that subjects following a keto diet lost muscle mass, while also losing weight (*).
Whereas others theorize that in the absence of glucose, ketone bodies can be used to displace glucose — leaving your lean muscle mass undisturbed (*).
Another found that the presence of the ketone body beta-hydroxybutyrate decreased the oxidation (breakdown) of the amino acid leucine while promoting muscle synthesis (*).
Here is what we do know, when you lose weight no matter what diet you follow, you usually lose fat, but also some muscle. With keto, most of it comes from fat — not muscle (*).
In other words, eating a low-carb keto diet may help you burn away excess fat while preserving your lean muscle mass when compared to other types of weight loss diets.
Supports Blood Sugar
Naturally, as you reduce your carb intake, your blood sugar becomes more stable. However, when you eat a low-carb diet, it has more benefits for your glucose response.
Weight loss is one strategy that doctors suggest to help reduce the risk of developing type 2 diabetes. However, research shows that for people with metabolic syndrome (a precursor to diabetes), following a low-carb diet can turn around metabolic syndrome regardless of weight loss.
That’s because low-carb dieting has a positive effect on health markers like triglycerides, cholesterol, and blood sugar (*).
In one study, researchers put a group of patients with type 2 diabetes on a ketogenic diet to assess its role in blood sugar regulation. After 16 weeks on the ketogenic diet, 80% of the participants either reduced their medication dose or discontinued medication altogether (*).
Considering the side effects that can come along with diabetes medications like kidney complications, controlling diabetes with diet could lead to better long-term blood sugar control and fewer negative outcomes (*).
Chronic inflammation goes hand in hand with diseases like stroke, respiratory disease, heart disease, cancer, and diabetes. (*). Therefore, controlling chronic inflammation in your body may be the single most vital thing you can do for long-term health.
Due to its anti-inflammatory effects, the ketogenic diet has been used since the 1920s to help children with epilepsy control their seizures (*).
While the exact mechanisms for the anti-inflammatory effect of keto are still being uncovered, the ketone body beta-hydroxybutyrate (BHB) is one interesting area of focus.
Research shows that BHB can block something called the NLRP3 inflammasome. The NLRP3 inflammasome is a protein complex that releases inflammatory chemicals in your body, initiating an inflammatory response and can even result in cell death (*).
Other research suggests that glucose metabolism is linked to inflammation. Therefore, by reducing carbs (glucose), the ketogenic diet offers an alternative fuel source that does not instigate inflammatory responses (*).
What’s more, animal research shows that following a ketogenic diet not only diminishes inflammation — but may also help reduce pain (*).
May Promote Heart Health
For years the popular theory was that saturated fat was the primary cause of heart disease, and therefore diets low in fat should be followed to protect heart health. Of course, as history would show, this led to low-fat dieting and the subsequent obesity epidemic (*).
In fact, the ketogenic diet may be the answer to better heart health. Heart disease has several biomarkers associated with it, including inflammation and high blood lipids.
Studies suggest that inflammation may play an instigating role in heart disease by causing damage to the walls of your arteries and initiating the oxidation of cholesterol in your blood. These two factors combined result in the formation of arterial plaques that lead to heart disease (*).
It has also been reported that adults with diabetes are two to four times more likely to die from heart disease than adults without diabetes. Since the ketogenic diet can support healthy blood sugar, it offers yet another way to protect your heart (*).
Therefore, the anti-inflammatory and blood sugar effects of the ketogenic diet may help protect your heart from disease.
Affects Athletic Performance
Whether you’re an endurance athlete or prefer resistance training, the keto diet can support your athletic endeavors, and research shows may even improve performance.
Contrary to popular belief, carb-loading may not be the answer for endurance athletes that are looking for sustained energy. While keeping glucose flowing may sound like a good idea on paper, the fact of the matter is that glucose is a temperamental fuel source that fluctuates much more than ketones.
In endurance athletes, keto-adaptation not only enhances body composition, but it also increases fat oxidation. That means that when athletes are training, their body more efficiently taps into their fat stores to produce ketones that fuel their muscles.
This is evidenced by increased sprint power, as well as longer periods of peak power before reaching fatigue (*).
In one study, ultra-endurance runners that were keto-adapted burned over twice as much fat as high-carb runners (*).
In regards to strength training, the old adage “fat burns in a carbohydrate flame” falls flat when you look at keto-adapted athletes.
For years it was believed that carbohydrates were needed to protect muscle breakdown. The thought process was that once glucose was diminished, your body would turn to your muscles to break down amino acids for fuel.
Some research shows that when you’re keto-adapted, your lean body mass may be protected from catabolic breakdown, but as we mentioned the research remind mixed. We do know that people performing resistance training on keto tend to lose more fat which may give you a leaner appearance, compared to those following a high carb diet (*).
Having a sharp mind as you age is just as vital as having a healthy, fit body.
Neurological diseases are marked by both neuro-inflammation and disruption in energy utilization. This disruption in energy comes from dysfunction in cellular organelles called mitochondria. Your mitochondria, also known as the powerhouse of the cell, provide the energy you need on a cellular level for all the vital workings of your brain (* , *, *).
What’s more, elderly patients consuming a ketogenic diet show improved working memory, visual attention, and task switching on-demand (*).
Rich In Dietary Fiber
Many people claim that low-carb diets lack dietary fiber because they avoid high fiber foods like beans and whole grains.
In reality, nothing could be farther from the truth. The ketogenic diet is packed with fiber-rich foods like low-carb vegetables, nuts, and seeds.
Dietary fiber not only supports digestion and prevents constipation, but it also supports heart health, helps in the prevention of diabetes, and aids in weight loss.
The keto diet can be rich in both soluble and insoluble fiber, with soluble fiber helping to reduce cholesterol and blood glucose levels, and insoluble adding bulk and promoting healthy stools (*).
Rich In Vital Micronutrients
Some sources claim that following a ketogenic diet that restricts carbs can lead to vitamin and mineral deficiencies due to a low intake of fruits and vegetables. This comes from the common misconception that the keto diet is meat and fat heavy and low in plant foods.
However, a well-balanced low-carbohydrate diet is full of veggies like broccoli, cauliflower, bok choy, peppers, sprouts, leafy greens, and so on. These foods provide a wide array of vitamins and minerals, as well as antioxidants and other phytonutrients that are necessary for the function of every cell in your body (*).
In contrast, diets that are full of processed foods and refined carbohydrates lack the essential nutrients your body needs and are linked to weight gain, insulin resistance, diabetes, and potentially heart disease (* , *, *).
If you are considering keto long-term you might want to understand that there may also be some health risks associated with this eating pattern. Here are some of the potential downsides of long-term keto.
Limits Social Eating
While keto might allow for you to eat a lot of your favorite foods and many high carb foods can be “keto-fied”, you still might feel restricted since you are limited to eating low carb foods.
This can make social events, holiday gatherings, or situations where you can’t control your food, a bit challenging. Friends and family might not understand why you don’t want to indulge with them in a family-style pasta meal or enjoy birthday cake at a party.
While these types of social situations might not bother you, overtime not “fitting in” can be difficult. And it might get annoying to always have to explain your choices to others.
Depending on your lifestyle and who you regularly share meals with, this may or may not be an issue for you when following keto long-term. But, it is something to think about before you decide to adopt this different way of eating.
Promotes Black and White Thinking
While there are multiple health benefits of following a keto diet, either in the short or long term, maintaining ketosis does require you to stick pretty closely to the diet. Overdoing it on carbohydrates, even by a small amount, can kick you out of ketosis.
Additionally, most of us are surrounded by a wide variety of highly palatable, high carbohydrate foods. It can be difficult not to indulge sometimes. This can lead to black and white thinking over food and eating. Either you are being “good” and eating keto, or you are being “bad” and are not eating keto.
For some people, if they slip up, they can simply jump back on the wagon at the next meal without a lot of drama.
For others, one slip-up means days of beating themselves up or simply leads to a binge. If making one “wrong” choice leads you to overeat or give up, keto might not be the diet for you.
Research has found that black and white thinking around food can make it difficult for people to maintain a normal body weight (*). Black and white thinking can negate the potential benefits of a long-term keto diet.
With diets like keto that have strict rules around what you can and can’t eat, associating these rules with how “good” or “bad” you are doing on your diet, is a path to failure.
Instead, if you do want to eat a keto diet for the health benefits, focus on the positives rather than the limitations. Look for foods that you enjoy and feel satisfying to you.
And lastly, if you do slip up, don’t beat yourself up. Just jump right back on and make a keto-friendly choice at your next meal or snack.
May Lead to Weight Regain
The keto diet is incredible for weight loss. But, like any diet, if you don’t change your habits long-term you will simply gain the weight back.
As with any change in your eating, you have to be willing to commit to the plan long-term or find a happy medium that allows you to maintain your weight.
Once you stop eating keto, if you don’t maintain a healthy eating pattern, you will likely gain the weight back and more. In fact, about 80% of dieters gain the weight back and find themselves heavier than when they first started (*).
Additionally, research has found that for every kilogram (2.2 pounds) you lose, your body increases your appetite by about 100 calories per day (*).
Your body is not trying to sabotage your goals, it is just trying to maintain the status quo. It increases your appetite to help you stay the same weight. This is the reason why keeping weight off long-term is hard.
So, how do you keep the weight off if you decide to lose weight following a keto diet? You need to maintain a lower calorie intake long-term. This means that you can either continue to eat keto to control calories or adopt a calorie-controlled diet using some other method.
The bottom line is that if you go back to your old habits, you will likely gain the weight back.
Can Lead to Vitamin Deficiencies
We did say that the keto diet is nutritious and provides all the vitamins and minerals you need. But, this is if it is well-planned.
Many people use keto as an excuse to eat all the bacon, steak, and cheese they want. While these foods are allowed on keto and do have vitamins and minerals, they do not provide other essential nutrients your body needs.
Eating keto does not give you an excuse to not eat your vegetables. If you skip the low-carb veggies, you may very well end up with vitamin and mineral deficiencies.
To avoid any deficiencies, balance your intake of high protein foods, like meat and chicken, with a wide variety of non-starchy vegetables. Aim for at least 5-9 servings per day of vegetables to ensure you are getting all the vitamins and minerals you need.
You may also want to consider a daily multivitamin just to fill in any nutrient gaps you might be missing.
May Not Be Good for Cholesterol Levels
While we already discussed the potential benefits of the keto diet for heart health, the research on what a high-fat diet does to LDL cholesterol is mixed.
Studies have found that while keto increases LDL (bad) cholesterol, it increased the larger, fluffier LDL, not the dense, sticky LDL that cloggs up your arteries. Fluffier, larger LDL particles do not have a negative effect on heart health (* , *).
Other studies paint a different picture of the impact of a long-term keto diet on LDL cholesterol. A 2017 study found that a long-term keto diet increased small LDL while decreasing larger healthier LDL (*).
So, which is it? Does keto increase or decrease large LDL? The answer may depend on the individual. At this time, more research is needed to fully understand how a high-fat diet can impact LDL cholesterol levels and whether that increases the risk of heart disease.
If you do want to eat a keto diet long-term, you can do it safely.
Start by speaking to your doctor or healthcare provider. They can help address any health concerns with following a keto diet long-term. Regular lab work can also help keep tabs on any nutrient deficiencies and monitor blood lipids.
Second, an understanding of how to create a well-balanced, nutrient-dense keto diet, by including a wide variety of foods, with an emphasis on low-carb vegetables. Consider adding a multivitamin to help fill any potential nutrient gaps.
Finally, listen to your body. While many people do feel better eating a keto diet, it may not be the ideal diet for every person. If you are feeling overly fatigued, struggling with extreme cravings, or experiencing other negative side effects, it may not be the best diet for you. Your body is always the best judge of what eating pattern is best for you.
The short-term effects of being in ketosis often look like increased energy, weight loss, and enhanced cognitive function.
The long-term effects of low-carb high-fat dieting, however, offer many more benefits than what you see after a month or two on keto. But, it may also have some downsides.
By reducing your carbohydrate intake, you may support the health of your heart, reduce the impact of glucose on your body, support your athletic performance, and reduce your risk for obesity as well as neurological and inflammatory diseases.
There are also some potential downsides to eating keto. Knowing the pros and cons of any eating pattern can help you choose the diet that works best for you.
Perissiou M et al. The Effect of an 8 Week Prescribed Exercise and Low-Carbohydrate Diet on Cardiorespiratory Fitness, Body Composition and Cardiometabolic Risk Factors in Obese Individuals: A Randomised Controlled Trial. 2020 February 14
Alarcón M et al. Excessive refined carbohydrates and scarce micronutrients intakes increase inflammatory mediators and insulin resistance in prepubertal and pubertal obese children independently of obesity. 2014 November 16