A sweeping 2025 study titled “The Broad Spectrum Species: Plant Use and Processing as Deep Time Adaptations”, published in Journal of Archaeological Research, fundamentally re-examines what early humans ate, and in doing so, challenges the popular mythology behind the modern “paleo diet.” Rather than being strictly meat-eating hunters, our ancestors apparently relied heavily on a broad variety of plants and sophisticated methods to process them.
We’re A “Broad-Spectrum” Species
The authors (and their fossil / archaeobotanical evidence) argue we should think of humans not as specialized carnivores, but as a “broad-spectrum species”, meaning that our evolutionary success is rooted in flexibility and dietary diversity.
Rather than not eating plant foods until agriculture arose, the record shows robust and consistent use of wild seeds, nuts, tubers and roots as well as complex processing techniques such as grinding, pounding, cooking, and detoxifying.
At sites dating back tens of thousands of years, early humans were already grinding wild seeds, cooking starchy tubers, and consuming processed plant foods long before any formal agriculture.
Why Plant Processing Matters
Many plant foods, such as seeds, roots, tubers and nuts are dense in carbohydrates, fiber, micronutrients, but often locked behind indigestible fibers or toxic compounds. The innovation of processing plants by grinding, roasting, and cooking unlocked these nutrients and made such foods digestible, calorie-rich, and safe. The 2025 study argues this capacity was a key evolutionary threshold for hominins, enabling them to thrive in many environments around the globe.
In other words, eating plants wasn’t a fallback, rather it was a central, adaptive strategy. That runs contrary to the popular image promoted by many paleo-diet advocates of humans as primarily meat-eaters who only reluctantly ate plants when meat was scarce.
Given this evolutionary background, there’s a strong argument that whole-food, plant-based diets or Mediterranean-style diets may actually be more aligned with our species’ deep dietary heritage and healthier in the long run, rather than restrictive, meat-heavy paleo regimens.
Dietary Diversity — The Original Human Strength
Our ancestors didn’t rely on a narrow set of foods. They exploited a wide range of plant foods depending on environment, season, and availability. That dietary flexibility is a hallmark of human evolutionary success.
A plant-based or Mediterranean-style diet mirrors this diversity with vegetables, fruits, whole grains, legumes, nuts, seeds, olive oil and herbs. This diversity supports a broad spectrum of nutrients including fiber, complex carbohydrates, micronutrients, healthy fats, and phytochemicals.
While meat provides protein and fat, heavy reliance on it, especially processed or high-fat meats, has been associated with higher rates of heart disease, certain cancers, and other chronic diseases in modern contexts. By contrast, whole-food, plant-based diets emphasize complex carbs, fiber, antioxidants, and healthy fats like those from nuts and olive oil.
Given our ancestors processed plants to maximize nutrient uptake, it’s plausible that a plant-rich diet delivered the carbohydrates, vitamins, minerals, and energy needed for survival and brain development without excessive meat consumption.
Better Lifelong Health
Modern medical and nutritional research (e.g., influenced by works like The China Study) has repeatedly shown benefits of diets rich in whole plants: lower risk of cardiovascular disease, better weight management, improved metabolic health, and potentially lower risk of some cancers.
A Mediterranean-style or whole-food plant-based diet incorporates traditional, minimally processed foods, often linked to lower rates of “diseases of civilization” that proliferated with overly processed, high-meat Western diets.
Why the “Paleo Diet” Narrative Is Misleading
The popular form of the “paleo diet” often claims to replicate what early humans ate: lots of meat, little processed foods, no grains or legumes. But the 2025 paper undermines that assumption:
- Early humans already processed plant foods – grinding wild seeds, roasting tubers, cooking – long before agriculture.
- Archaeological evidence shows that in many ancient communities, plant foods accounted for a large portion of calories, especially in temperate or tropical zones.
- The “strict meat-based” paleo narrative ignores the versatility and adaptability that actually enabled our ancestors to spread across environments worldwide, from Africa to Australia to Eurasia.
In short, the human evolutionary story supports omnivory + flexibility, not a rigid meat-heavy diet.
A Vision for Eating Today
Given what we now know, both from anthropology/archaeology and modern nutrition science, here’s a recommended approach to eating
- Base your diet on whole, minimally processed plant foods: vegetables, fruits, whole grains, legumes, nuts, seeds.
- Include healthy fats (e.g., olive oil, nuts, seeds) rather than saturated fats from heavy meat or processed meats.
- Use modest amounts of high-quality animal products – fish, poultry and red meat (preferably free range and/or grass fed)
- Favor dietary diversity – mix many plant types, rotate grains & legumes, eat seasonal produce – echoing ancestral dietary flexibility.
- Minimize processed foods, refined sugars, artificial additives and lean toward traditional, simple cooking and whole foods.
This resembles a classic Mediterranean diet or a whole-food, plant-predominant diet, and seems to align with both our evolutionary heritage and modern health research.
This study does more than revise academic theories of human diet. It reframes our understanding of what it means to be human: flexible, innovative, adaptive, and deeply tied to plants.
If you care about long-term health and longevity, or simply want to eat in a way that resonates with what made Homo sapiens successful, a whole-food, plant-based or Mediterranean-style diet makes profound sense. It’s a return to our roots.
Author
Scott Rollins, MD, is Board Certified with the American Board of Family Practice and the American Board of Anti-Aging and Regenerative Medicine. He specializes in Bioidentical Hormone Replacement for men and women, thyroid and adrenal disorders, fibromyalgia, weight loss and other complex medical conditions. He is founder and medical director of the Integrative Medicine Center of Western Colorado (www.imcwc.com) and Bellezza Laser Aesthetics (www.bellezzalaser.com). Call 245-6911 for an appointment or more information.
