Dietary Differences: Keto vs. Atkins® vs. Paleo vs. Whole30®

If you’re focused on healthy eating, then you’ve likely heard of the ketogenic (keto), Paleolithic (Paleo), Atkins, and Whole30 diets. But what’s the best way to determine the most appropriate diet for your needs and preferences?

All four of the abovementioned food plans are low-carb in nature. Keto and Atkins take a deliberately low-carb approach to eating, but Atkins does not limit protein, while keto is low-to-moderate in protein; another key difference is that while Atkins is generally touted as a short-term weight loss solution, keto is viewed as a lifestyle.

Meanwhile, the Paleo and Whole30 diets involve the elimination of processed foods and grains—categories known for their high carbohydrate content.

Now let’s highlight each of the four diets and dive into their similarities and differences.

  1. Ketogenic diet
      • Founded by Dr. Russell Wilder at the Mayo Clinic, the ketogenic diet was created in 1924.1 Today it’s viewed as a tool that utilizes metabolism to shift energy pathways in the body.
      • The idea is that you can achieve ketosis—a shift from using carbohydrates as fuel to using fats—by consuming specific percentages of macronutrients.2
      • Here’s the keto macronutrient breakdown:
        • 70% of daily calories from fats
        • 20% of daily calories from proteins
        • 10% of daily calories from carbs
      • By restricting your carbohydrate intake between 20 and 50 grams per day, and subsequently increasing your fat intake, your body initiates the process of ketosis and produces ketone bodies. Ketones are produced from the breakdown of fats in the liver.
      • To this end, since excess proteins can easily be converted to blood sugar, it’s ideal to opt for full-fat rather than low-fat protein options.
      • Most keto dieters track their macronutrient levels to monitor their dietary progress; some even test their blood, breath, or urine to confirm they are in a state of nutritional ketosis.
      • Those who follow the ketogenic diet avoid processed foods, starchy vegetables, gluten, grains, legumes, and sugars (including natural ones). Instead, they eat nonstarchy vegetables, nuts and seeds, meats and poultry, fish and seafood, eggs, low-glycemic fruits like berries, heart-healthy fats, non-nutritive  sweeteners like stevia, and full-fat dairy options.
    • The keto diet is known for reduced feelings of hunger as compared to other diets. It is also known for promoting breakdown of fat rather than muscle during exercise and in some cases has been said to enhance exercise performance, as ketone-made ATP releases more energy than glucose-made ATP.3 Stress reduction is another benefit of keto.4
  1. Atkins diet
      • The Atkins diet was developed by Dr. Robert C. Atkins in the 1960s and promotes weight loss by encouraging dieters to track their “net carbs”—that is, the difference between an item’s carb content and its fiber content.5 For instance, if three spears of asparagus have 1.8 grams of carbs and 0.9 grams of fiber, then their net carbs total 0.9 grams.
      • A low net carb quantity is ideal in the Atkins diet. It’s also worth noting that the definition of net carbs isn’t regulated, and the term is used rather loosely. The above explanation outlines what is taught in the Atkins program.
          • The diet consists of four phases:5
          • Phase 1: Induction
          • This initial phase lasts about two weeks. During this time, the dieter cuts carbs from the diet, with the aim of consuming 20 grams of net carbs per day.
          • Those who follow the Atkins diet avoid consuming processed foods, starchy foods, sugars, grains, nuts, legumes, and alcohol during this phase. Instead, they eat “foundation” vegetables like asparagus, bell peppers, broccoli, celery, cucumber, and green beans. These vegetables should comprise 12 to 15 grams of their net carbs. They also eat meats and poultry, fish and seafood, eggs, heart-healthy fats, and full-fat dairy.
          • Phase 2: Balancing
          • Dieters continue to get 12 to 15 grams of their daily net carbs from foundation vegetables in this phase. And while they still avoid foods with added sugar, they can start incorporating nutrient-dense foods like berries, as well as nuts and seeds, back into their diet. This phase should last until the person is 10 pounds from their target weight.
          • Phase 3: Premaintenance
          • Dieters stay in this phase until they reach their goal weight and continue broadening the range of foods they eat during this time. They can add up to 10 grams of carbs back into their diet each week and revisit items like fruits, starchy vegetables, and whole grains.
          • Phase 4: Lifetime maintenance
        • The fourth and final phase is simply maintenance for dieters who have reached their goal weight.
    • The main difference between Atkins and keto is that while both promote a low-carbohydrate diet, Atkins doesn’t limit protein intake nor encourage a higher fat intake. While the Atkins diet is viewed as a weight-loss solution, keto is meant to induce major—and, if followed carefully, longer term—metabolic changes.
  1. Paleolithic diet
      • Chances are you’ve heard the phrase “caveman diet.” The Paleolithic diet focuses on the consumption of high-quality foods, with the aim of avoiding processed ingredients and instead adopting our ancestors’ eating habits from the Paleolithic era.
      • Paleo emphasizes items that were once procured by hunting and gathering and limits foods that became mainstream when farming took off approximately 10,000 years ago, such as dairy products, legumes, grains, added sugar, and hydrogenated oils.
      • In short, the Paleolithic diet proposes that modern dietary practices are misaligned with the human body.6 Dieters who swear by Paleo consume high quantities of vegetables, meats, fish, and healthy fats, along with fruits, nuts, and seeds in moderation. Research reveals that the diet may trigger weight loss among other benefits.6
      • Contrary to keto and Atkins, there is no official macronutrient profile defined for Paleo. That said, nutrient-dense yet starchy vegetables like sweet potatoes, and natural sweeteners like maple syrup, are generally allowed in Paleo but not in keto (and only sometimes in Atkins).
    • In addition, Paleolithic dieters—who have the option to consume healthy fats like olive or coconut oil—generally get fewer calories from fats than their ketogenic and Atkins counterparts. And unlike keto and Atkins, but similar to Whole30, Paleo is a dairy-free food plan.
  1. Whole30 diet
      • Whole30 co-creator Melissa Hartwig, CISSN introduced her 30-day diet in 2009.7 The elimination program consists of cutting out certain food groups over the course of a month.7
      • For 30 days, Whole30 participants steer clear of added sugars (including natural sweeteners), alcohol, grains, legumes, and dairy. Carrageenan, MSG, and sulfite should also be avoided.
      • Even baked goods and processed foods prepared with otherwise approved ingredients are far from ideal, as eating these treats will—according to the program—make it difficult to keep cravings at bay. Those who slip up are asked to restart the food plan from day one.
      • But there are exceptions to the rule: Despite the list of banned ingredients, ghee and clarified butter, natural fruit juices, certain legumes (green beans, sugar snap peas, and snow peas), vinegar, coconut aminos, and salt are all considered acceptable ingredients.7
    • Recommended foods include meats and poultry, seafood, eggs, high quantities of vegetables, some fruits, natural fats, and plenty of herbs and spices. It’s best to eat foods with few ingredients—or, ideally, only one ingredient because the item in question is unprocessed.

There are countless diets out there. And ultimately, although Whole30 is structurally different from keto, Atkins, and Paleo, the program urges dieters to avoid processed foods, eliminate refined sugars, and lower their carb intake.

This article doesn’t advocate any particular diet. Before starting any diet please consult your healthcare practitioner.

Atkins® is a registered trademark of Atkins Nutritionals, Inc.
Whole30® is a registered trademark of Thirty & Co, LLC


  1. Wheless JW. History of the ketogenic diet. Epilepsia. 2008;49(Suppl 8):3–5.
  2. Volek JS et al. Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutr Metab (Lond). 2004;1(1):13.
  3. Cox PJ et al. Acute nutritional ketosis: implications for exercise performance and metabolism. Extrem Physiol Med. 2014;3:17.
  4. Hallbook T et al. The effects of the ketogenic diet on behavior and cognition. Epilepsy Res. 2012;100(3):304-309.
  5. Mayo Clinic. Atkins Diet: What’s behind the claims? Mayo Clinic. Accessed June 7, 2018.
  6. Mayo Clinic Staff. Paleo diet: What is it and why is it so popular? Accessed June 7, 2018.
  7. Whole30. The Official Whole30 Program Rules. Accessed June 7, 2018.

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