What Is the Paleo Diet?
The paleo diet, sometimes referred to as “the caveman diet,” is based on the principle that eating foods that were available to early humans will promote optimal health.
One of the fundamental theories behind the paleo diet is that modern food systems, production and processing techniques are damaging to human health.
Thus, if you adjust your eating style to mimic that of Paleolithic hunter-gatherers, you will better support your body’s natural biological function, improving digestion and health.
Paleo eliminates grains, legumes, processed sugar and most sources of dairy.
The main foods permitted on the paleo diet include:
- Meat and fish
- Nuts and seeds
- Vegetables — except corn, which is a grain
- Selected fats and oils, such as coconut oil, olive oil, avocado oil, lard, tallow, ghee/butter
- Minimally processed sweeteners, including raw honey, maple syrup, coconut sugar, raw stevia
For most, paleo is about more than just a diet.
There is also a strong focus on lifestyle practices, the environmental impact of food choices and total body wellness within the framework of the paleo philosophy.
What Is the Keto Diet?
Most tissues in the human body prefer using the glucose from carbohydrates for energy.
Ketosis is the metabolic state in which your body uses calories from fat, instead of carbs, to create the energy needed to carry out its normal functions
The keto, or ketogenic, diet aims to induce ketosis through the calculated adjustment of dietary macronutrients, namely carbs, protein and fat.
The keto diet macronutrient breakdown looks something like this:
- Fat: 60–80%
- Protein: 20–30%
- Carbohydrates: 5–10%
In comparison to a “standard” diet, the macronutrient distribution of the keto diet is shifted significantly in favor of fat, with moderate protein and very few carbs.
The purpose of achieving ketosis with this diet plan is to induce the metabolic breakdown of fat in your body. Thus, it’s imperative that macronutrient intake is tightly controlled, as otherwise you risk throwing your metabolism out of ketosis.
One of the main reasons that the keto diet has gained recent popularity is because of its potential to help you lose weight and improve blood sugar control
Although they are distinct, paleo and keto diets share many characteristics. Below are some of the main ideas these diets have in common.
Both Emphasize Whole Foods
Fundamentally, both paleo and keto diet plans are intended to rely on whole-food sources of nutrients.
A whole food is a food that has undergone a minimal amount of processing by the time it gets to your plate.
Both keto and paleo diets strongly encourage eliminating all ultra-processed foods and replacing them with whole foods like fresh vegetables, meat, fish and nuts.
This is especially evident with the exclusion of processed fats, oils and sweeteners in both paleo and keto “rule books.”
Both Eliminate Grains and Legumes
Though for different reasons, both paleo and keto diets strongly discourage eating grains and legumes.
For the paleo crowd, this elimination is largely based on the fact that grains and legumes were not likely part of early human diets and they contain antinutrients.
Antinutrients are compounds, such as lectins and phytates, that can be found in some plant-based foods. They interfere with your body’s ability to absorb minerals and nutrients and may cause digestive distress when eaten in large quantities
On the other hand, research suggests that there may also be benefits to eating foods with these compounds
The keto diet also eliminates grains and most legumes, but this is because of their carbohydrate content.
Grains and legumes contribute a significant amount of carbs to the diet. If you eat them while following the keto diet, you risk throwing your body out of ketosis.
Both Eliminate Added Sugar
Keto and paleo diets strongly discourage the intake of added sugars.
For both diet plans, this largely falls under their shared message of avoiding heavily processed foods in general.
However, paleo dieters are a bit more flexible with this rule, as unrefined sugar sources like honey and maple syrup are still permitted.
Keto, on the other hand, doesn’t allow any added sugar sources, refined or not, due to the high carb content of these foods.
Both Emphasize Healthy Fats
In line with their shared goal of achieving optimal health, both paleo and keto diets encourage the intake of unrefined, healthy fats.
Both diets also recommend moderate-to-liberal amounts of selected refined oils, such as olive and avocado oils, as well as nuts, seeds and fish. These foods are known to benefit heart health because of their poly- and monounsaturated fat content
Both diets also discourage the use of heavily processed fats, such as trans fats, which are detrimental to health when consumed regularly
Keto places very heavy emphasis on fat in general, as it is the cornerstone of the entire diet. Paleo, while not necessarily a high-fat diet, uses this recommendation to support overall health.
Both May Be Effective for Weight Loss
One of the primary reasons for the popularity of keto and paleo diets is the notion that they will promote weight loss.
Unfortunately, there is limited research available for how effective these diets are for sustained, long-term weight loss. However, some short-term research is promising.
A small study of postmenopausal, obese women following the paleo diet showed a 9% weight loss after six months and a 10.6% loss at 12 months. No additional significant change in weight was seen at the 24-month mark
One review of research on low-carb, high-fat (LCHF) diets, such as the ketogenic diet, indicated that short-term weight loss can occur when switching to this style of eating
This may have been because a high intake of fat usually leads to a decrease in appetite and fewer overall calories consumed. It may also be that the process of ketosis is leading to more efficient elimination of the body’s fat stores. The exact reason is still unclear.
Ultimately, more research is needed to determine a clear causal relationship