Paleo diet

Related Terms

Caveman diet, dairy-free diet, diet, fad diet, gluten-free diet, high-fat diet, high-protein diet, hunter-gatherer diet, low-carbohydrate diet, low carb diet, paleodiet, paleolithic diet, Stone Age diet, wheat-free diet.

Background

During the Paleolithic Age (or Old Stone Age), which began approximately 2.5 million years ago and ended approximately 10,000 years ago, the human diet included wild meat, fish, insects, eggs, fruit, berries, vegetables, and nuts. These foods were consumed in amounts dependent on the area in which the humans were living. Rarely consumed foods included seeds and beans, potatoes, grains, dairy, and refined fat, sugar, and oil.
The present-day paleo (caveman) diet is based on this diet. Some experts suggest that this diet is the healthiest for humans. Supporters of the diet suggest that chronic illnesses, such as type 2 diabetes, cancer, and heart disease, are due to the consumption of foods not commonly consumed during the Paleolithic age. They also claim that evidence suggests a lack of chronic disease in the humans that lived during this age.
Supporters of the paleo diet claim that it prevents cancer, heart disease, and osteoporosis. They also claim that it promotes energy, weight loss, and general health. However, strong clinical evidence is lacking for the use of the paleo diet for any condition.

Theory

The paleo diet is based on the diet of humans living in the Paleolithic Age. During this time, humans ate wild meat, fish, insects, eggs, fruit, berries, vegetables (including fungi and roots), and nuts. Up to 40 percent of calories come from meat and fish in the paleo diet, with the remaining calories coming from unsaturated fat (up to 35 percent) and fruits and vegetables (up to 45 percent). Carbohydrate intake is low, as fruit is the major source of carbohydrates. Foods including grains, legumes, dairy products, potatoes, and refined salt, sugar, and oils are generally excluded.
The paleo diet is considered to be higher in protein, lower in carbohydrate, higher in fiber (non-starchy vegetables and fruits), moderate to higher in fat, higher in potassium, lower in sodium, and higher in many micronutrients.
Compared to the 15 percent protein intake in the average Western diet, the paleo diet is thought to contain 19-35 percent protein. The paleo diet may decrease energy intake by 36 percent, as well as reduce calcium intake and improve dietary fat composition, antioxidants, and the potassium-sodium ratio. The paleo diet is higher in monounsaturated and polyunsaturated fats (including omega-3 and omega-6 fatty acids) than the average Western diet. The foods consumed in the paleo diet are thought to increase the pH of bodily fluids, which may improve bone and muscle strength, lower blood pressure, and decrease the risk of kidney stones and asthma.
The paleo diet has been found to significantly reduce the intake of cereals, dairy, potatoes, beans, baked products, total energy, energy density, carbohydrates, fiber, saturated fatty acids, and calcium. It has been found to significantly increase intake of fruits, vegetables, meat, eggs, monosaccharides, dietary cholesterol, vitamins (B6, C, and niacin), minerals (potassium and selenium), protein, and fat.
Clinical trials have studied the inclusion of lean meat, fish, dried fruit, leafy and root vegetables (including one medium-sized potato daily), eggs (two daily), and walnuts in the paleo diet. Dairy foods, cereal grains, refined fats, sugar, beans, excess salt, and soft drinks or beer were excluded. However, rapeseed or olive oil (less than one tablespoon daily) and one glass of wine daily were allowed. Another description of the caveman diet includes avoiding grains, meats, fruits, and vegetables, and consuming yams, broccoli, cauliflower, carrots, brussels sprouts, cherries, pineapple, peanuts, shellfish and grains such as amaranth, quinoa, and buckwheat.
The paleo diet does not restrict the quantity of food intake. Natural hunger cues are used to initiate eating. The paleo diet is not considered a temporary fix to lose weight, but rather a lifestyle. Returning to a normal diet after weight loss would negate all the benefits of the diet. Those who follow the paleo diet also exercise regularly, especially heavy weight training and intensive cardiovascular exercise. Although the paleo diet is usually practiced alone, the recent surge in popularity has created regional groups in large cities who are dedicated to the paleo diet.
For appetite suppression, the paleo diet has been consumed for three months or 12 weeks.
For heart disease prevention, the paleo diet has been consumed for three weeks or ten days.
For diabetes, the paleo diet has been consumed for three months or 12 weeks.
For gum disease, a diet similar to the paleo diet has been consumed for four weeks.
For weight loss, the paleo diet has been consumed for three weeks to three months.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Early study suggests that the paleo diet may increase feelings of fullness. Available studies conducted by the same authors have allowed for foods not traditionally included in the paleo diet, such as potatoes and dried fruit. These studies also suggest increased weight loss compared to other diets. Further research is needed before firm conclusions can be made.

 C


Early study suggests that the paleo diet may increase feelings of fullness. Available studies conducted by the same authors have allowed for foods not traditionally included in the paleo diet, such as potatoes and dried fruit. These studies also suggest increased weight loss compared to other diets. Further research is needed before firm conclusions can be made.

 C


The paleo diet may improve blood sugar levels and heart disease risk factors in type 2 diabetics when compared to a standard diabetes diet. In people with ischemic heart disease (reduced blood supply to the heart), the paleo diet was found to reduce waist circumference and improve blood sugar; however, effects on weight were lacking. Further study is needed before conclusions can be made.

 C


The paleo diet may improve blood sugar levels and heart disease risk factors in type 2 diabetics when compared to a standard diabetes diet. In people with ischemic heart disease (reduced blood supply to the heart), the paleo diet was found to reduce waist circumference and improve blood sugar; however, effects on weight were lacking. Further study is needed before conclusions can be made.

 C


In the absence of oral hygiene, the paleo diet may increase plaque levels but decrease gum bleeding in healthy people. A decrease in tongue bacteria and an increase in gum bacteria have been found. More research is needed to make conclusions on the effect of the paleo diet for gum disease.

 C


In the absence of oral hygiene, the paleo diet may increase plaque levels but decrease gum bleeding in healthy people. A decrease in tongue bacteria and an increase in gum bacteria have been found. More research is needed to make conclusions on the effect of the paleo diet for gum disease.

 C


Early studies suggest that the paleo diet may reduce weight, waist circumference, and blood pressure in healthy people. The paleo diet may improve blood sugar levels and heart disease risk factors in type 2 diabetics when compared to a standard diabetes diet. The diet may also improve blood pressure, blood sugar, and cholesterol in sedentary healthy people. However, the long-term effects of the paleo diet on heart disease are unclear. Further study is needed.

 C


Early studies suggest that the paleo diet may reduce weight, waist circumference, and blood pressure in healthy people. The paleo diet may improve blood sugar levels and heart disease risk factors in type 2 diabetics when compared to a standard diabetes diet. The diet may also improve blood pressure, blood sugar, and cholesterol in sedentary healthy people. However, the long-term effects of the paleo diet on heart disease are unclear. Further study is needed.

 C


Early study suggests that the paleo diet may increase feelings of fullness. Available studies conducted by the same authors have allowed for foods not traditionally included in the paleo diet, such as potatoes and dried fruit. These studies also suggest increased weight loss and decreased waist circumference. In people with ischemic heart disease (reduced blood supply to the heart), the paleo diet was found to reduce waist circumference and improve blood sugar; however, effects on weight were lacking. More research is needed in this area.

 C


Early study suggests that the paleo diet may increase feelings of fullness. Available studies conducted by the same authors have allowed for foods not traditionally included in the paleo diet, such as potatoes and dried fruit. These studies also suggest increased weight loss and decreased waist circumference. In people with ischemic heart disease (reduced blood supply to the heart), the paleo diet was found to reduce waist circumference and improve blood sugar; however, effects on weight were lacking. More research is needed in this area.

 C
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Safety

Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

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