The transition from eating traditional human diets rich in “natural” whole foods, to the western dietary pattern characterized by high intakes of processed and refined food, is associated with weight gain, alterations in the human microbiome, increased intestinal permeability, poor nutritional status, low-level chronic inflammation, and disease. An evolutionary perspective on nutrition in combination with modern scientific research provides the best framework for determining the optimal human diet. The Ancestral Diet is a perfect starting point/template for good nutrition in the 21st century.
What to eat?
- Eat primarily nutritious whole foods such as meat, fish, fowl, eggs, vegetables, fruits, berries, and nuts.
- Reduce or eliminate your consumption of cereal grains. Traditional processing techniques such as soaking and fermentation will make whole grains and legumes easier to digest and should be employed if these foods constitute a large part of your diet.
- Grass-fed, full-fat dairy products such as GHEE, yogurt, kefir, and butter are usually well tolerated.
- Get at least 15% of your daily energy from protein. A higher protein intake (>20%) is usually beneficial.
- Include sources of probiotics (e.g., fermented food, uncleaned vegetables from the garden or farmers market) and prebiotics (e.g., leeks, onions, green bananas) in your diet.
- Regularly eat fatty fish, organ meats, and/or other foods high in omega-3 and vitamin D.
- Food choices and macronutrient ratio should be determined based on activity level and goals.
- Choose organic, grass-fed and/or wild produce if possible.
Why should I eat this way?
Plenty of nutrition-related topics have been covered in detail on the site, but here’s a brief summary of some important principles underlying the diet:
- Hunter-gatherers and people eating traditional diets are virtually free from chronic disease, and the transition from eating natural food to processed and refined food is associated with a rapid decline in health (1,2,3,4,5,6).
- Although the macronutrient ratio of the diet could influence health, bodyweight, and longevity, studies show that humans have thrived on both high-carbohydrate- (7,8,9,10,11,12), and high-fat diets (13,14).
- Recent systematic reviews show that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of heart disease, stroke, or cardiovascular disease (15,16).
- Both studies in animals and humans show that the appetite for protein is so strong that you will “keep eating” until you get enough protein. Lack of protein in the diet could lead to weight gain (17,18).
- Some toxins and antinutrients found in plant foods such as grains and legumes could negatively impact health (19,20,21,22,23). Alterations in the human microbiome has been linked to increased incidence of grain- and gluten-related disorders and may explain why so many people feel better once they remove grains from their diet. Traditional food processing techniques such as soaking, sprouting, and fermentation increase the bioavailability of many nutrients and reduce or eliminate many toxins and antinutrients.
- Perturbations of the human microbiome seem to be an important underlying cause of inflammation and have been associated with several chronic health disorders, such as cancer, gallstones, and arthritis (24,25,26). Gut dysbiosis and increased intestinal permeability also seem to play an important role in obesity (27,28,29). Consumption of prebiotics and probiotics promotes a healthier microbiome and has also been linked to several other benefits, such as better immunity, increased production of short-chain fatty acids, and improved digestion (30,31,32,33).
- The majority of studies suggest that low-carbohydrate diets promote greater weight loss compared to low-fat diets (34,35,36,37,38). “Nutrition transition patterns and the health of those still eating diverse ancestral diets with abundant food suggest that neither glycemic index, altered fat, nor carbohydrate intake can be intrinsic causes of obesity, and that human energy homeostasis functions well without Westernized foods containing flours, sugar, and refined fats” (39). While it seems that reducing the overall carbohydrate content of the diet is linked to increased weight loss, it’s possible that acelluar and refined carbohydrates are the major offenders that promote an inflammatory microbiota, chronic low-level inflammation, and weight gain. Antinutrients found in cereal grains, legumes, and other foods with a relatively high carbohydrate content could further stall weight loss (40). Low-carb diets typically contain more protein, and elevated protein intake is associated with better satiety and appetite regulation (17,18).
- Food reward plays an important role in overweight and obesity, and the consumption of modern hyper-palatable and hyper-rewarding food (e.g., processed calorie-dense foods rich in fat and/or sugar) seems to disrupt the brain’s mechanisms for regulating food intake (41,42,43,44,45,46).
“…the increased palatability of the diet initiates a vicious cycle in which hedonics cause more food to be eaten than is necessary to meet energy needs, and the increased calories in turn initiate events that lead to insulin/leptin resistance and a consequent tendency to eat even more food” (46).