One of the most common misconceptions is that a low-carbohydrate diet equals a ketogenic diet. Both a low-carb diet and a keto diet focus on eliminating carbohydrates, but there are some important differences between keto vs. low-carb as well as the way they impact your overall health.
Low-carb and keto diets share a central goal: decreasing the number of carbs you eat. Excess carbs — especially refined carbs like sugar, flour, white bread, and pasta — contribute to weight gain and a variety of chronic diseases, including[*][*][*][*][*][*][*]:
- Type 2 diabetes
- Heart disease
- Higher insulin resistance
- Lower insulin sensitivity
- Chronic inflammation
- Digestive upsets and irregularity
- Anxiety, depression, and irritability
Both low-carb and keto diets cut out excess carbohydrate intake. However, there are important differences between low-carb and keto, and learning more about how each diet works is crucial to decide which one will suit you best.
What Defines a Low-Carb Diet?
The Government Dietary Guidelines for Americans suggest that carbohydrates make up 45% to 65% of your total daily calories[*].
That means if you’re eating 2,000 calories a day, between 900 and 1,300 of those calories should come from carbohydrates[*].
There are no official guidelines when it comes to low-carb diets, apart from macro breakdown, dietary restrictions, or eating patterns.
Low-carb (also called low-carb, high-fat, or LCHF) is generally considered any diet where calories from carbs range between 20% to 45% of your daily calorie intake. This translates to staying under roughly 200 grams of total carbs per day[*].
Most low-carb diets focus on food quality, cutting out high-carb refined foods like sugar, bread, pasta, soda, high-fructose corn syrup, and baked goods. More strict low-carb diets may even cut other carbs like fruits.
But a low-carb diet doesn’t define a set number of carbs to stay under each day based on your body’s needs or goals. It gives you room to adjust your diet and find the carb intake that makes you feel best, whether that’s 80 grams of carbs a day or 200.
Low-carbohydrate diets don’t usually recommend testing for ketone bodies — the little bundles of energy you make when you’re in fat-burning mode — or getting into a state of ketosis.
What Defines a Keto Diet?
While a low-carb diet may not have any strict rules to follow, a ketogenic diet is defined by staying in a specific metabolic state called ketosis. To get and stay in ketosis, it’s required that you eat very few net carbs — usually under 50 grams a day.
In ketosis, your body doesn’t have any carbs to burn for energy, so it switches over to burning fatty acids instead. For most people, that means keeping a total daily carb count between 20 and 50 grams per day paired with moderate protein intake and increased healthy fat intake (like avocado and grass-fed butter)[*].
You should be strict about carb intake on keto, because if you eat too many carbs, your metabolism will switch off fat burning and go back to using those carbs as fuel. This will kick you out of ketosis and possibly hinder all the hard work you’ve put in towards your goal weight.
On a ketogenic diet, your macronutrients are very important. Everyone has unique and specific needs, therefore finding out your ideal macro values is key to success.
Many keto followers also find it helpful to test their ketone levels. Testing will help you determine whether or not your body is actually in ketosis.
The dedication to follow a keto lifestyle will pay off, as it offers one-of-a-kind health benefits that a low-carb diet does not.
Both low-carb and keto diets are great for weight loss[*].
However, a keto diet can make it easier for you to lose weight by keeping you full on fewer calories.
One of the side effects of ketosis is hunger suppression. Ketones control ghrelin and cholecystokinin, two of your body’s main hunger hormones. A ketogenic diet can help promote long-lasting hunger suppression, that makes it easier to lose weight[*][*].
In one study, 17 obese men were given either a keto diet (4% carbohydrate) or a moderately low-carb diet (35% carbohydrate), with no calorie restrictions on either diet.
The people on the keto diet[*]:
- Ate almost 300 fewer calories per day (without consciously restricting calories)
- Reported less overall hunger
- Lost more weight
Unlike the ups and downs you experience when your primary source of energy is glucose, when you’re in ketosis your body can sustain itself for hours using stored body fat.
You can also combine a keto diet with intermittent fasting for even greater health and fat loss results, and you won’t feel as hungry as you would if you were eating carbs.
If you want to lose weight, a keto diet may give you an edge over a low-carb diet.
There are numerous benefits on a keto diet: from helping to lower chronic inflammation to assisting in slowing tumor growth in patients diagnosed with prostate, pancreatic, brain, lung, and gastric cancer, this lifestyle brings numerous health benefits[*][*].
#1. Better Energy Levels on Keto
Keto gives you more mental and physical energy to tackle workouts, busy days, and errands with the kids. This may be because ketones are a more efficient fuel source than glucose[*].
Ketones also easily cross the blood-brain barrier, so your brain can use them efficiently for energy. This may contribute to sustained mental performance and higher productivity levels.
That said, you may find you have more stable energy on a low-carb diet, especially if you work out a lot. If that’s the case, try adding some carbs back into your diet, either by going low-carb or by trying a modified version of keto like targeted keto or cyclical keto. Both are great for athletes and still offer many of the benefits of being in ketosis.
#2. Greater Blood Sugar Control
In a small group of obese patients with type 2 diabetes, a low-carbohydrate diet resulted in[*]:
- Participants eating fewer calories organically (by almost 1,000).
- Around three pounds of weight loss in 14 days.
- Normalized blood sugar levels.
- A 75% improvement in insulin levels.
A low-carb diet is great for managing blood sugar and type 2 diabetes, but keto seems to have better results.
In one study, 21 participants with type 2 diabetes went on a keto diet for 16 weeks. By the end of the study[*]:
- 33% of participants got off their diabetes medication entirely.
- 48% of participants reduced their diabetes medication by more than half.
- Fasting triglyceride levels (a risk factor for heart disease and diet-related liver damage) decreased by 42%.
- Participants lost an average of 6.6% body fat.
Whichever diet you choose, cutting the amount of carbs you consume will help you manage blood sugar, insulin resistance, and decrease the risk of diabetes.
#3. Better Mental Health and Cognitive Protection
Ketosis may offer long-term neurological protection against neurodegeneration and diseases such as Alzheimer’s, Parkinson’s, and epilepsy[*].
The ketogenic diet was created to prevent seizures in people with epilepsy, and it’s been effective for more than a century at treating those who became drug-resistant[*].
Ketones are particularly good for your brain in a few different ways:
- Ketones act as antioxidants, protecting your brain cells from oxidative stress and damage[*].
- Ketosis can give you more mental energy. Keto decreases stress on mitochondria, the powerhouses that make energy in your brain. It also increases mitochondrial efficiency and overall energy production[*][*].
These amazing mental health benefits are unique to those who follow a ketogenic, high-fat diet.
While research on using a keto diet for epilepsy began back in the 1920s, scientists and medical experts are just starting to study and learn the long-term effects of following a very low-carb, keto lifestyle.
Keto May Help You Stay Mentally Sharp
A study found that ketones protected against oxidative damage in several brain regions, including the hippocampus — your brain’s memory center and one of the first brain regions to deteriorate in dementia[*].
Following keto long-term could protect your brain from mental decline and neurodegeneration, keeping you independent and mentally strong for your entire life.
Keto May Extend Your Lifespan
Being in ketosis may also extend your lifespan.
Several animal studies have found that ketosis promotes longevity, while human research is underway. This research is based on the theory that ketones alter your gene expression, slowing down aging and thus promoting a long, healthy life[*].
Other Long-Term Benefits of Keto
Current research suggests a keto diet may be more effective than low-carb diets at managing, treating, and potentially even reversing[*]:
- Type 2 diabetes
- High blood pressure
- High blood sugar levels
- Heart disease
- Polycystic ovary syndrome
- Nonalcoholic fatty liver disease
- Alzheimer’s disease
- Parkinson’s disease
- Autism spectrum disorder
The Takeaway: Keto vs. Low-Carb
The biggest difference between keto and low-carb diets is nutritional ketosis, the metabolic state of using fat as your energy source instead of glucose.
Nutrition is personal. It depends on genetics, environmental factors, gut bacteria, and more.
Ultimately, your goal shouldn’t be to find a diet that works for everyone else. It should be to tailor your diet to your own body and figure out how to feel the best that you can.
Keto works for a lot of people, and because ketosis offers so many unique benefits, trying it at least once can be incredibly beneficial to you.
You may find you feel better than you thought possible — or you may find you do better on a low-carb diet or a low-fat diet.
Regardless, it’s worth your time to experiment with keto — and with this complete beginner’s guide to a ketogenic diet, you can start your journey today.
Keto meal plans are also of great help when you’re just starting out. Give it a try and see how you feel.
For more reading, check out these articles that compare the keto diet with other types of diets:
- Keto Diet vs. the Mediterranean Diet
- Keto vs. Paleo: Is Ketosis Better Than Paleo?
- Keto vs. Atkins: What Are the Differences and Which One Is Better?
If you’re not sure about keto, try these keto-friendly recipes and discover how delicious it can be: