Keto vs Paleo: Which Diet is Better for You

If you’re standing in the health aisle wondering which trendy diet to try, you’re not alone. The ketogenic and paleo diets have dominated nutrition conversations for years, each promising impressive health benefits from weight loss to better energy levels. But here’s the truth: these two popular eating plans are fundamentally different, despite what social media might suggest.

While both diets eliminate processed foods and emphasise whole ingredients, they approach nutrition from completely different angles. The keto diet is a precise macronutrient formula designed to put your body into fat-burning ketosis, while paleo is a lifestyle philosophy based on eating like our ancient ancestors. Understanding these differences is crucial before you commit to either approach.

Let’s break down exactly what sets these diets apart, explore their science-backed benefits and potential risks, and help you determine which one—if either—matches your health goals and lifestyle.

Understanding the Keto Diet: Fat-Fueled Metabolism

The ketogenic diet isn’t just another low-carb trend. It’s a carefully calculated eating plan that fundamentally changes how your body produces energy.

How Keto Works

On a standard diet, your body burns glucose from carbohydrates for fuel. The keto diet flips this switch by drastically restricting carbs to force your body into ketosis—a metabolic state where your liver converts stored fat into ketones for energy.

To achieve and maintain ketosis, keto requires strict macronutrient ratios:

70-80% of calories from fat
20-25% from protein
Only 5-10% from carbohydrates (typically 20-50 grams daily)

This isn’t a casual eating plan. You’re essentially training your body to become a fat-burning machine instead of a sugar-burning one.

What You Can Eat on Keto

The keto diet allows:

Encouraged foods: Fatty meats, seafood, eggs, butter and cream, full-fat cheese, nuts and seeds, healthy oils (olive, coconut, avocado), low-carb vegetables (leafy greens, broccoli, cauliflower, peppers), avocados, and small amounts of berries.

Foods to avoid: All grains and grain products, legumes and beans, most fruits, starchy vegetables (potatoes, corn, squash), sugar and sweeteners, most dairy milk, and any high-carb processed foods.

The key difference? Everything revolves around keeping carbs minimal enough to stay in ketosis.

Science-Backed Benefits of Keto

Research has revealed several impressive health benefits of the ketogenic diet:

Weight loss: Multiple studies show keto produces significant short-term weight loss. A meta-analysis found that people on very low-carb ketogenic diets experienced greater long-term weight loss compared to low-fat diets, with decreases in body weight, triglycerides, and blood pressure.

Blood sugar control: The keto diet helps patients with diabetes reduce HbA1c levels and decrease insulin requirements. One study showed improved glucose control and reduced body weight in participants following a well-formulated ketogenic diet.

Heart health markers: Research published in the American Journal of Clinical Nutrition found that keto can lower inflammation markers and reduce LDL cholesterol levels—both significant risk factors for heart disease.

Mental health benefits: A 2024 Stanford pilot study found that participants with severe mental illness who followed a ketogenic diet for four months experienced a 31% improvement on psychiatric rating scales, along with better sleep, mood, and quality of life.

Metabolic syndrome reversal: Research showed that 29% of participants had metabolic syndrome before starting keto, but after four months, none met the criteria anymore.

Understanding the Paleo Diet: Eating Like Our Ancestors

The paleo diet takes a completely different philosophical approach. Instead of manipulating macronutrients, it focuses on food quality and eliminating modern processed foods.

The Paleo Philosophy

Paleo advocates believe that our bodies are genetically adapted to the foods our Palaeolithic ancestors ate before agriculture emerged about 10,000 years ago. The diet eliminates foods that became common after the agricultural revolution—grains, legumes, dairy, and processed foods, in favour of whole foods humans could hunt or gather.

Unlike keto’s strict macro ratios, paleo is more flexible. The typical macronutrient breakdown is approximately 35% fat, with moderate protein and carbs depending on fruit and vegetable consumption.

What You Can Eat on Paleo

The paleo diet includes:

Encouraged foods: Grass-fed meats, wild-caught fish, free-range poultry, eggs, vegetables (all types), fruits, nuts and seeds, healthy oils from fruits and nuts (olive, coconut, avocado, almond), herbs and spices, and tubers like sweet potatoes.

Foods to avoid: All grains (wheat, rice, oats, barley), legumes (beans, lentils, peanuts, soy), dairy products, refined sugars and artificial sweeteners, processed foods and trans fats, salt, and low-fat or diet products.

The emphasis is on food quality, choosing organic, grass-fed, and wild-caught options whenever possible.

Science-Backed Benefits of Paleo

Research on the paleo diet has shown promising short-term results:

Weight loss: A systematic review found that following a paleo diet resulted in an average weight loss of 5.8 kg, with decreased waist circumference and BMI compared to control diets. Another study showed a mean weight loss of 3.52 kg in paleo followers.

Metabolic improvements: Studies found that paleo led to reduced waist circumference, healthier triglyceride and cholesterol levels, lower blood pressure, lower fasting blood sugar, and reduced inflammation markers.

Cardiovascular benefits: A large study of young adults in Spain found that the paleo diet was linked to lower cardiovascular risk factors, mostly from avoiding highly processed foods and eating more fruits and vegetables.

Blood sugar control: Research shows paleo can improve glucose and insulin levels, potentially lowering the risk of type 2 diabetes.

Keto vs Paleo: Key Differences Explained

While both diets share some similarities, their differences are significant.

Similarities Between the Diets

Both keto and paleo:

Eliminate processed foods, refined sugars, and artificial ingredients
Exclude grains and most legumes (though for different reasons)
Emphasise whole, nutrient-dense foods
Encourage healthy fat consumption
Promote moderate protein intake
Can help regulate blood sugar and improve insulin sensitivity
Require significant dietary restrictions

Critical Differences

The distinctions matter when choosing which diet suits your lifestyle:

Macronutrient focus: Keto requires precise macro ratios (70-80% fat) to maintain ketosis, while paleo is more flexible with macros and focuses on food quality over quantity.

Carbohydrate intake: Keto severely limits carbs to 20-50 grams daily, while paleo allows moderate carbs from fruits and starchy vegetables.

Dairy: Keto allows full-fat dairy products, while paleo excludes all dairy.

Sweeteners: Paleo permits natural sweeteners like honey and maple syrup; keto does not allow any high-carb sweeteners.

Primary goal: Keto aims to achieve metabolic ketosis for fat burning, while paleo aims to eliminate modern processed foods and return to ancestral eating patterns.

Food quality emphasis: Paleo strongly emphasises grass-fed, organic, and wild-caught foods, while keto focuses more on macronutrient content regardless of food quality.

The Risks and Downsides You Need to Know

No diet is without potential drawbacks. Understanding the risks helps you make an informed decision.

Keto Diet Risks

Long-term keto adherence may carry several health concerns:

Nutrient deficiencies: The restrictive nature of keto can lead to deficiencies in fibre, magnesium, vitamin C, and potassium, causing symptoms like constipation, muscle cramps, fatigue, and weakened immune function.

Sustainability challenges: Ketosis is like a light switch—either on or off. Most people find the strict carb restrictions difficult to maintain long-term. Studies show that once people stop keto, they regain at least half the weight they lost.

Long-term health risks: A 2021 meta-analysis of over 100 studies found that long-term keto diets are linked to increased risks of heart disease, kidney issues, certain cancers, and Alzheimer’s disease. Another study found that low-carb dieters who consume large amounts of meat and dairy may have higher risks of early death.

“Keto flu”: Many people experience foggy thinking, irritability, nausea, tiredness, and bad breath when starting keto.

Bone health concerns: Research links keto to decreased bone strength and reduced bone mineral density over time.

Organ stress: Recent research indicates that prolonged keto can cause hyperlipidemia, liver dysfunction, and glucose intolerance due to increased stress on the liver and pancreas.

Paleo Diet Risks

The paleo diet also presents potential health concerns:

Nutrient deficiencies: Eliminating dairy, grains, and legumes increases the risk of calcium, vitamin D, fibre, and B-vitamin deficiencies. You’d need to eat five or more servings daily of certain greens or bone-in fish to meet calcium requirements.

High red meat intake: Many paleo followers consume large amounts of red meat, which studies link to increased risk of heart disease, cancer, fatty liver, reduced kidney function, and loss of bone density.

Digestive issues: Transitioning to paleo’s high-fibre foods can cause bloating, diarrhoea, constipation, weakness, and headaches, especially for those coming from low-fibre diets.

Gut microbiome changes: Studies show paleo may elevate TMAO levels—a compound produced by gut bacteria from animal products that’s associated with increased cardiovascular disease risk—possibly due to lack of prebiotic fibre from whole grains and legumes.

Cost and convenience: Fresh meats, fish, and produce are more expensive than processed alternatives, and the diet requires significant time for meal planning and cooking.

Limited long-term research: There’s insufficient evidence proving paleo’s long-term health benefits or risks, as most studies are short-term with small sample sizes.

Which Diet is Better for Weight Loss?

Both diets can produce weight loss, but they work differently and have distinct sustainability profiles.

The keto diet typically produces faster initial weight loss due to ketosis and water weight loss from depleted glycogen stores. Studies show average losses of 10-13% of starting weight in short-term trials. However, research indicates that much of this weight returns once people resume normal eating patterns.

The paleo diet produces more modest but potentially more sustainable weight loss. Studies show average losses of 3.5-5.8 kg over several months. The weight loss comes primarily from eliminating high-calorie processed foods and increased satiety from protein and fibre.

The verdict: Keto wins for rapid short-term weight loss, but paleo may be easier to maintain long-term, which is crucial for keeping weight off. Remember, sustainable lifestyle changes matter more than dramatic initial results.

Which Diet Is Easier to Follow?

Sustainability is where these diets differ dramatically.

Keto’s challenges: The extremely restrictive carb limit makes keto notoriously difficult to maintain. You must constantly track macros and test for ketosis. Eating out becomes complicated, and even a single high-carb meal can knock you out of ketosis. Social situations involving bread, pasta, or desserts become challenging.

Paleo’s challenges: While paleo allows more food variety and doesn’t require macro tracking, it demands careful label reading since processed foods are everywhere. You can’t always tell if a restaurant meal meets paleo criteria. However, paleo’s flexibility with carbs from fruits and vegetables makes it psychologically easier for many people.

Registered dietitian Bannister notes that “the paleo diet has a bit more of a balanced approach by allowing for fruits, veggies, and some sugars,” while “the strong emphasis on fats in the keto diet can be a bit concerning, especially for cardiovascular health long term”.

Which Diet Should You Choose?

The “better” diet depends entirely on your individual goals, health status, and lifestyle.

Consider keto if you:

Want rapid short-term weight loss or metabolic reset
Have type 2 diabetes or prediabetes and need better blood sugar control
Are willing to meticulously track macros and test for ketosis
Don’t mind extremely limited carb options
Can commit for a defined period (not necessarily long-term)
Have medical supervision, especially if you have existing health conditions

Consider paleo if you:

Prefer a more flexible, intuitive eating approach
Want to focus on food quality over macro calculations
Enjoy fruits and starchy vegetables
Are willing to invest in higher-quality ingredients
Seek a potentially more sustainable long-term lifestyle
Have digestive issues or sensitivities to grains and dairy

Avoid both diets if you:

Are you pregnant or trying to conceive (both pose risks)
Have chronic kidney disease (protein load concerns)
Are vegetarian or vegan (very difficult to follow)
Have a history of disordered eating (restrictive nature may trigger issues)
Cannot afford higher food costs or time for meal preparation

A Balanced Perspective: What Experts Say

Harvard nutritionist Deirdre Tobias cautions that the health benefits attributed to paleo may actually come from “cutting out processed foods and ramping up fruits and vegetables” rather than the specific paleo framework. She notes there’s no evidence paleo provides greater long-term benefits than well-studied diets like the Mediterranean or plant-based diets.

Similarly, cardiologist Dr Baljash Singh Cheema emphasises that with keto, “sustainable change over time is far more important” than rapid weight loss that’s regained once the diet ends.

The bottom line? Both diets can work in the short term, but neither may be necessary or optimal for long-term health compared to balanced, less restrictive approaches.

The Takeaway: Choose What Works for YOU

Neither keto nor paleo is universally “better.” The most effective diet is the one you can sustain while meeting your nutritional needs and health goals.

If you want rapid metabolic changes and don’t mind strict macro tracking, keto might work for a defined period with medical supervision. If you prefer food quality focus with more flexibility, paleo could be a more sustainable long-term approach.

However, consider this: you might not need either. Many people achieve excellent health outcomes simply by eating more whole foods, lots of vegetables, quality proteins, healthy fats, and fewer processed items—without eliminating entire food groups.

Before starting any restrictive diet, consult with a healthcare provider or registered dietitian who can assess your individual health status, nutritional needs, and risk factors. They can help you create a personalised approach that supports your goals without unnecessary restrictions or health risks.

The best diet isn’t the trendiest one; it’s the one that nourishes your body, fits your lifestyle, and makes you feel your best for years to come.