Paleo Diet: Eating Like Our Ancestors

The Evolutionary Premise

The paleolithic diet — commonly called the "paleo diet" or "ancestral diet" — is based on the hypothesis that human genetics and physiology are optimized for the food environment of the Paleolithic era (approximately 2.5 million to 10,000 years ago), before the advent of agriculture. Proponents argue that foods introduced through farming and industrialization — grains, legumes, dairy, refined sugars, and processed oils — are at odds with our evolutionary heritage and contribute to modern chronic disease.

The framework was popularized by gastroenterologist Walter Voegtlin in the 1970s and further developed by Loren Cordain, whose 2002 book The Paleo Diet brought the concept to mainstream audiences. It is important to note that the diet of actual Paleolithic humans varied dramatically by geography and season; there was no single ancestral diet.

Foods Included and Excluded

Paleo-Approved Foods

• Meat: beef, lamb, pork, game (bison, venison), organ meats — ideally grass-fed or pasture-raised
• Poultry: chicken, turkey, duck — ideally pasture-raised
• Fish and seafood: wild-caught salmon, tuna, sardines, shrimp, shellfish
• Eggs: preferably free-range
• Vegetables: all non-starchy vegetables, root vegetables including sweet potatoes and beets
• Fruits: all fruits, though portion moderation is sometimes recommended for high-sugar options
• Nuts and seeds: almonds, walnuts, macadamia, cashews, chia, flaxseed (peanuts excluded — they are legumes)
• Fats and oils: olive oil, coconut oil, avocado oil, animal fats (lard, tallow, duck fat)
• Herbs and spices: all

Excluded Foods

• All grains (wheat, rice, oats, corn, barley, rye)
• All legumes (beans, lentils, chickpeas, soy, peanuts)
• Dairy products (some modified paleo versions allow grass-fed butter or ghee)
• Refined sugars and artificial sweeteners
• Processed and industrial seed oils (canola, soybean, sunflower, corn oil)
• Salt (debated in some paleo frameworks)
• Alcohol and most packaged foods

Nutritional Profile

The paleo diet typically produces a distinctive macronutrient profile compared to standard Western diets:

The paleo diet is notably high in fiber relative to most modern diets because it relies on large volumes of vegetables and fruits rather than grains. It also eliminates nearly all added sugars and ultra-processed foods, which may account for much of its reported benefit.

Research Evidence

Clinical research on the paleo diet is growing but limited by small sample sizes and short durations:

• Metabolic syndrome: Several randomized controlled trials find the paleo diet superior to heart-healthy dietary guidelines for reducing waist circumference, triglycerides, blood pressure, and fasting glucose in people with metabolic syndrome.
• Weight loss: Short-term trials consistently show greater weight loss with paleo compared to conventional dietary guidelines, though differences often diminish at 2-year follow-up when compared to other low-carb or Mediterranean patterns.
• Blood sugar: A 3-month RCT in type 2 diabetics found paleo reduced HbA1c by 1.5 % compared to 0.5 % with a conventional diabetes diet.
• Criticisms: The elimination of legumes and whole grains removes some of the most evidence-based foods for longevity and gut health. The diet can be expensive and socially restrictive. Calcium intake may be insufficient without dairy unless large amounts of fish with bones or green vegetables are consumed.

Practical Tips for Following Paleo

• Focus on food quality rather than perfect historical accuracy — the goal is eliminating processed foods and refined sugars.
• Eat plenty of vegetables to meet fiber and micronutrient needs that would otherwise come from grains and legumes.
• Include fatty fish at least twice a week for omega-3 fatty acids.
• Monitor calcium intake: aim for 3–4 servings of green leafy vegetables or bone-in fish (sardines, salmon canned with bones) daily.
• Sweet potatoes, plantains, and beets can provide satisfying carbohydrates, particularly around workouts.
• The strictness of paleo can be adjusted — many practitioners follow an 80/20 approach, allowing occasional non-paleo foods.