Fact-checked by Dr. Anthony Gustin, DC, MS.
Written by Brenda Godinez
Are keto and Atkins the same thing or is one better than the other?
The ketogenic diet and the famous Atkin’s Diet of the 1990’s often get lumped into the same conversation as one and the same. But there are definitely differences between the two diets, and the real comparison might surprise you!
To truly highlight the differences between each diet, let’s take a look at each individually, including pros and cons, then examine which is better and why.
The ketogenic diet is based on eating a specific percentage of macronutrients:
- High fats: 70-80% of daily calories.
- Adequate protein: 20-25% of daily calories.
- Low carbohydrates: 5-10% of daily calories
In the absence of carbohydrates for an extended period of time, your liver converts stored fat into ketones, which can then be processed into ATP, the energy currency of your cells.
An elevated level of ketone bodies in the blood leads to a state known as nutritional ketosis, which is the goal of the keto diet.
This radical change of fuels — from glucose to ketones — is what makes the keto diet so special and beneficial.
The 9 Benefits of the Ketogenic Diet
The ketogenic diet radically transforms many aspects of your health. Here are 9 science-backed reasons to be in a state of ketosis:
#1. Unlocks Metabolic Flexibility
The ketogenic diet is different than regular weight loss diets because it changes something fundamental in your body: the fuel your cells run on.
On virtually any other diet, your cells use glucose for energy.
On keto, ketones replace glucose as the main energy source.
This change triggers metabolic flexibility — the ability to switch between fuels (fat or carbs) when needed and use both efficiently.
For someone who has never done keto before, losing access to carbs triggers unpleasant side effects like low energy, headaches, and bad mood.
Someone who has done keto has an easier time switching between fat and carbs for energy without side effects.
For example, a keto-adapted person could go on vacation and enjoy carb-based foods for a few days and then switch back to a state of ketosis in a day or less by cutting carbs, eating fatty foods, and fasting.
This metabolic flexibility was common in our hunter-gatherer ancestors, who constantly switched between a state of fasting (where the body runs on ketones) and eating, according to food availability.
In essence, ketosis restores the metabolic flexibility our bodies evolved to have, which protects us against obesity and diabetes.[*]
#2: Stabilizes Blood Sugar
Relying on ketones instead of glucose keeps your blood sugar low and stable. That’s why the ketogenic diet helps to:
- Lower glucose levels
- Increase insulin sensitivity
- Prevent and reduce insulin resistance
Being sensitive to insulin is paramount to health. The more sensitive you are, the better your body processes carbs and the easier it is to lose weight.
It also prevents insulin resistance, which is a precursor to type II diabetes, obesity, and non-alcoholic fatty liver disease.
#3: Triggers Burning of Stored Body Fat
The keto diet is extremely effective for fat loss because it resets your body’s enzymatic machinery to burn fat for fuel instead of glycogen.
This means your cells run on stored fat, so you’ll lose weight faster and easier.
#4. Accelerates Weight Loss
Research finds keto is one of the most effective weight loss strategies both in the short-term and long-term.
The most dramatic weight loss can be seen in the first few months on the keto diet, which is ideal if you want quick results (and who doesn’t?).
Don’t worry about gaining back the weight — keto is not a yo-yo diet. When you lose weight on keto, you actually keep it off.
A recent review found that people on a ketogenic diet achieve greater weight loss in the long-term compared to people following a conventional low-fat diet.[*]
As you can see in the graph, a very low carb, ketogenic diet (VLCK) produced the greatest fat loss and weight loss in both men and women:
#5. Boosts Exercise Performance
Bodybuilders preparing for competitions, athletes, and casual gym-goers alike opt for the keto diet to get better performance results.
Here are some of the advantages of working out while following a ketogenic diet:
- Ketone-made ATP releases more total energy than glucose-made ATP [*], so you have more available energy to power through your workout.
- Keto accelerates fat burning while exercising. A study found the rate of intramuscular fat burning increased 20-fold while exercising on ketosis.[*]
- Because your body is using fat and not glucose, glycogen reserves fill up faster, which boosts recovery.
- Ketones can improve performance in endurance exercises and boost fat loss during resistance training.
Additionally, when you exercise on keto, you only lose fat, not muscle. A recent study showed that Crossfit athletes were able to lose an average of 7.5 pounds and 2.6% body fat in just 6 weeks while maintaining muscle mass and increasing their performance.[*]
#6. Improves Brain Health
Since ketone bodies easily cross the blood-brain barrier, your brain can use them efficiently for energy, leading to sustained mental performance and long-term neurological protection against diseases such as Alzheimer’s,, Parkinson’s, epilepsy, and neurodegeneration[*].
Ketones can do wonders for your mental health and brain function, including:
- Preserving neurons and synapses — which improves memory, focus, attention, and learning.
- Lower neuroinflammation
- Lower risk of dementia
- Antidepressant and antianxiety-like effects
- Improved cognition in people with dementia.
#7. May Increase Lifespan
Ketosis triggers mechanisms that can help extend your lifespan.
One of them is improved gene expression. Ketosis unlocks genes that fight oxidative stress and regulate metabolism, which boosts longevity[*].
The other one is mitochondria protection. In the process of making ketones like BHB, many antioxidants are created in your mitochondria and dangerous oxidants are suppressed, which protects your cells against disease. This means keto triggers a powerful antioxidant effect that simply doesn’t happen when you’re running on glucose.
This antioxidant protection is amazing for your brain.
Research finds that ketones prevent and reverse oxidative damage in neurons, the hippocampus, and neocortex,[*] effectively preserving cognition and mental sharpness through the years, which severely improves your quality of life.
#8. Optimizes Heart Function
Ketosis is good for your heart.
Ketones have antioxidant effects on the lining of your blood vessels, can boost circulation, and improve the efficiency of your heart.
#9. Prevents Multiple Diseases
Ketones have major antioxidant and antiinflammatory effects[*] that can prevent the onset of degenerative and chronic diseases like:
- Alzheimer’s Disease
- Parkinson’s Disease
- Cancer (especially in the brain, pancreas, and colon)
- Huntington’s Disease
- Type II diabetes
- Heart disease
It’s especially helpful at fighting and preventing tumors because cancer cells rely on glucose to thrive while ketones impair their growth.
The tricky aspects of the ketogenic diet have to do with tracking, food choices, and the initial fat adaptation.
At least in the beginning, you have to measure your blood or urine ketone levels daily to make sure you’re in nutritional ketosis (burning ketones for energy). It’s easy to get kicked out of keto if you don’t track your food choices and ketones closely.
The most accurate way to measure your ketones is with a blood meter, such as the Precision Xtra Ketone Meter. It will give you the most accurate results, but the strips are expensive and some people have an aversion to drawing blood from their finger.
One good alternative are urine ketone strips. They’re more affordable and all you have to do is pee on the strip, no blood needed.
Tracking is more important on keto than other diets because you’re literally switching to a different metabolic fuel (ketones) and you won’t get the health benefits if you inadvertently go back to running on glucose.
However, as time goes on, you will learn which foods and drinks keep you in a ketogenic state and which kick you out of ketosis. Once you know this and become fat-adapted, eating keto becomes second nature.
To reach the right ketone levels, you have to hit specific keto macros.
Simply eating a lower carbohydrate diet isn’t enough, as your body needs a specific fat intake (70-80% daily calories) and carb intake (5-10% daily calories), which can prove challenging for beginners, especially those coming off a Standard American Diet (SAD).
However, these food choices become easy and intuitive once you’re on keto for a while.
A possible side effect soon after starting the ketogenic diet is the keto flu. As your body makes the switch from glucose to fats, you might experience flu-like symptoms including headaches, mental fog, body aches, and low motivation. It doesn’t happen to all people, and when it does it lasts no more than a few weeks.
Luckily, there’s a way to avoid the keto flu altogether. You can take exogenous ketones to get in ketosis immediately and bypass the fat-adaptation period. They will act just like body-made ketones and let you reap the benefits of ketosis from day one.
So, let’s recap:
Ketogenic Diet Pros
- You literally switch to a more efficient metabolic fuel (ketones!)
- Ketones have powerful antioxidant and antiinflammatory effects that fight and prevent disease.
- Ketones provide more energy than glucose.
- Ketosis leads to efficient fat loss while preserving muscle mass.
- Ketones improve exercise performance both in endurance and resistance training.
- Ketones improve mental performance and protect your brain against neurodegeneration.
- Ketosis can increase your lifespan and quality of life.
- Ketosis keeps blood sugar under control.
- The diet becomes more intuitive and easier to follow as you gain more knowledge and confidence.
- Scientific evidence supporting other benefits of ketosis for therapeutic purposes, performance, and overall health continues to emerge.
Ketogenic Diet Cons
- A low-carb, keto diet can feel somewhat restrictive at first.
- You have to monitor your food closely, count macros, and measure ketones in the beginning.
- Possibility of keto flu if you don’t take exogenous ketones
- Measuring blood ketones can be expensive
Now that we’ve established what the ketogenic diet is, what’s all the fuss about the Atkins Diet?
The Atkins Diet began a media storm in the early 2000s, prompting men and women alike to follow its low carb regime for supposedly effortless fat loss and better health.
The diet was proposed by Dr. Robert Coleman Atkins, an American physician and cardiologist.. In 1963, he discovered that reducing carbohydrate intake triggered weight loss without significant hunger, and he went on to publish his findings and diet advice in the now famous book Dr. Atkins’ Diet Revolution.
The current Atkins diet is now divided in two styles:
- The standard Atkins diet called Atkins 20, which limits more carbs and is designed for people with more than 40 pounds to lose.
- A new liberal version called Atkins 40, which allows more carbs and is designed for people with less than 40 pounds to lose.
Benefits of the Atkins Diet
The Atkins Diet is one of the most famous “fast track” diets which claims you can lose fat quickly by eating as much protein and fat as you want while avoiding high-carb foods. The diet claims to have been proven in over 80 clinical studies.
Atkins delivers on its weight loss claims because its low carb approach makes your body switch to fat-burning mode, so you experience accelerated fat loss.
However, these benefits are short-lived because the diet slowly introduces more carbs as it progresses. The diet is divided in 4 phases:
- Phase 1: Extremely low carb (20-25g carbs/daily). Kickstarts weight loss because the body enters fat-burning mode. Note the daily carbs are the same as in a ketogenic diet.
- Phase 2: Moderate carbs (25-50g carbs/daily). Here people find out how many carbs they can tolerate while losing weight. This carb limit means some people will switch back to burning glucose.
- Phase 3: Liberal carbs (50-80g carbs/daily). This is meant to stop weight loss as you’re reaching your “ideal” weight. At this level of carbs, most people are burning glucose.
- Phase 4: Abundant carbs (80-100g carbs/daily). This is a maintenance stage.
As you can see, the steady increase in carbs means you’re only on fat-burning mode for a short period of time and then maintain your goal weight with carbs.
There are two problems with the Atkins diet: the phase approach and the food philosophy.
Problems with the phase approach
The Atkins Diet is a short-term weight loss effort, not a lifestyle, so your chances of making long-lasting changes are slim.
The steady re-introduction of carbs after an accelerated weight loss period increases the likelihood of gaining your weight back.
This approach also emphasizes weight loss over other measures of health.
The Atkins Diet also fell out of popularity after reports that many people were getting sick, gaining weight over the long term, or increasing their blood lipid profile.
There was a heavy encouragement on the Atkins Diet that you could eat whatever you wanted and in whatever amount as long as it wasn’t carbohydrates. This lead to people overeating massive amounts of low-quality food, which lead to health problems.
Since then, they’ve updated their guidelines to prohibit processed foods.
Atkins Diet Pros
- Easy to follow because you can eat plenty of carbs in the later phases
- Quick fat loss in the early phases
- Reduces hunger and cravings
Atkins Diet Cons
- Possibility of gaining the weight back
- No mental or physical performance benefits
- Doesn’t help create metabolic flexibility
Keto is a lifestyle that changes your metabolic fuel and has many health benefits including –but not limited to– weight loss, while Atkins is mainly a short-term weight loss plan.
The Atkins diet is similar to the Keto diet only during the induction phase, where the dieter follows similar nutrient ratios as in the ketogenic diet.
This induction phase on Atkins sets carb intake at roughly 20-25 grams per day, which triggers fat burning in the body instead of using glycogen (glucose stores) for energy.
On a ketogenic diet, someone who eats 2,500 calories per day would eat around 30g of carbs.
At this point, the effects between the diets are similar. Not so coincidentally, this is the phase in which people experience the most weight loss on Atkins.
However, after this first stage, the diets begin to differ.
While the macros on the keto diet always stay the same, Atkins allows dieters to introduce more carbohydrates (albeit still a very limited quantity) once the initial phase is over.
In phases 2, 3 and 4 people go from 25 g to 100g of carbs a day, which puts them into glucose-burning mode.
Another caveat of the Atkins diet is it doesn’t emphasize fat, like keto does.
On the ketogenic diet, most of your daily calories should come from fat (up to 80%) so you can produce ketones. On Atkins, it’s not important whether you eat more protein or fat.
The initial weight loss results for those on Atkins are real, but they aren’t likely to last.
Those on the ketogenic diet can reap the weight loss and health benefits of running on ketones indefinitely and are more likely to keep the weight off.
At face value, the keto diet and Atkins seem to be pretty similar, since they both focus on low carb — and that’s where people get confused. But as you now know, there are big differences in approach and outcomes from each.
The ketogenic diet is a precise way of eating that changes your metabolism and the fuel your body uses for energy.
While the Atkins diet is easy to follow, it falls short both on weight loss and health benefits. when compared to the more effective ketogenic diet.
So, if you’re wondering whether to hop on keto or Atkins, it’s pretty clear that ketosis offers long-term health benefits that include and go beyond fast and effective weight loss.