The Paleo Diet has been an emerging protocol for dieting and sports in the past years.
Athletes, due to their energy expenditures and metabolic adaptations, require of special nutritional protocols. Is Paleo Diet good for athletes?
Best Diet for Athletes
Nutritional requirements for athletes are not the same than for other subjects.
Nutrition must be individualized and put in context. A lot of research has been done to optimize athletes' nutrition, and we can get to a consensus (study).
Nutrition's goals for athletes are simply to optimize sports performance. It is an important variable to consider to get stronger, more agile or/and better on their discipline (study)(study).
Following a proper diet or not can make the difference between first and second place.
High Carbohydrate Intake
Athletes may benefit from high carbohydrates intakes (study).
Carbohydrates are an effective fuel and source of energy for metabolic work and physical activities (study).
Carbohydrates are the most efficient molecule to produce energy quickly. Its consumption highly depends on the type of sport to be practiced.
Resistance and short-duration high-intensity trainings can rely more on the anaerobic pathways and direct ATP production. Endurance and long-duration low-intensity trainings rely mostly on the aerobic and glycolitic pathways (source)
Carbohydrates intakes pre, intra and post exercise are effectives strategies to fill and refill glycogen stores, respectively (study)(study).
Protein Quality and Quantity
When building muscle mass, protein intake serves as a substrate source, inducing structural changes and potentiating protein synthesis (source).
Athletes can benefit from higher intakes of protein due to the excess on muscle damage and 'catabolic' exercise.
Amino acids provided through protein intake will be used to 1) repair damaged muscle tissue and 2) construct new muscle tissue. But not only the quantity matters.
The quality here also has an important role in the effectiveness of the process. We need all essential amino acids to be able to construct new muscle tissue (study).
Leucine, one of the branched amino acids (BCAAS) plays a unique role in muscle growth, triggering and activating the process (study)
Protein intakes of ~2g/kg seem to be optimal for athletes (study), possibly showing more benefits with higher intakes.
Fats are Important
Recommendations of 0.8-1.2g/kg are optimal for fat intake (source).
Fats help stabilizing and adding rigidity to the cell membrane to function properly. Being the main components of these structures, their dietary intake is crucial for the proper cell functioning.
Fats are also important to stablish a good hormonal axis and environment (study)(study).
TAKE-HOME MESSAGES:
- Nutritional requirements for athletes are somewhat different from general populations
- Athletes require of higher carbohydrates intakes
- Protein quantity and quality determines the effectiveness of muscle growth
- Fats are needed to stabilize cell membranes, keep the hormonal axis functioning properly and to have a long term energy reservoir.
Is Paleo Diet for Athletes?
Can Paleo Diet fulfill all these requirement or should we consider some other protocol?
Paleo Contains High Quality Protein
Paleo Diets include protein source like meat, fish, shellfish, eggs and legumes. The lack of dairy products and milk protein made people think that paleo diets were not optimal for protein consumption.
Protein quality is based on its biological value. Whey protein and dairy are at the top of the table, but other sources like eggs have a score of 100 on their biological value.
Protein animal sources have a high biological value and are generally high in leucine(study).
Paleo Diet shouldn't be a problem when trying to achieve protein requirements for athletes. The use of protein animal sources combined with other plant sources such as legumes or nuts will do the work for you.
Paleo Diet provides Healthy Fats
Fats can be classified depending on the nature of their fatty acids.
Unsaturated fatty acids are associated with improved metabolic parameters (study), excess of saturated fats must be avoided (study)
Fat sources found in Paleo Diets are avocado, seeds, fatty fishes, nuts, red meats, and eggs.
Most of these fats are high on unsaturated acids, while only red meats are high in saturated fats.
Paleo Diets are not a problem in fulfilling fat requirements associated with health and proper metabolic function.
Content of Micronutrients in Paleo Diets
Micronutrients, including vitamins and minerals, play important roles in our metabolism.
They are involved in many metabolic reactions acting as essential cofactors or signal molecules (source).
Fulfilling the requirements of these substances can potentiate metabolic efficiency and sports performance.
Paleo Diets are high in vegetables and fruits, being one of the main sources of calories and carbohdyrates.
Looking at the nutrient density index created by RP (post), vegetables are generally one of the best sources of vitamins and minerals.
Paleo and Metabolic Health
Your diet should also improve your metabolic health. It's like having a Porsche and using "shitty" fuel.
At first nothing happens, but the engines start deteriorating slowly.
Our metabolism is the same. We need to provide all macronutrients and micronutrients to optimize, in this case, muscle building and body adaptations.
Vitamin D
Vitamin D plays important roles in our metabolism.
It acts binding to its receptor, VDR. The main effect attributed to vitamin D is related with bone health and absorption of calcium in the intestine (study)(study).
Calcium is involved and needed for muscle contraction, therefore enhancing muscle function (study)
VDR has also been found in muscle tissue, suggesting a positive effect on muscle function (study). Effectively, vitamin D affects muscle strength, and to a smaller extent muscle mass (meta-analysis).
Vitamin D deficiency has been associated with lower serum levels of testosterone (study).
Paleo Diets contain fish oils, which are one of the main dietary sources containing vitamin D. In fact, 10g of fish oil provides 1360UI of vitamin D.
This added to sun exposure shouldn't cause a problem.
Calcium
Calcium is one of the most abundant mineral in our organism. It has been associated with bone health, muscle contraction, nervous sytem and coagulation (study) (study) (study).
Calcium deficiency may lead to deteriorated nervous system and muscle contraction.
Paleo Diet restricts dairy products, which are the most known source of calcium. However, we can 'pay off' this with the high content of fruits and vegetables.
Bioavailability of calcium in fruits and vegetables is higher (study). We will need less total calcium to achieve the same serum levels of the active compound.
Fruits and vegetables are also alkaline. The potassium salts contained in fruiys lower calcium clearance and excretion through orine (study)
Paleo Diets are high in fruits and vegetables. These help achieving the required amounts of calcium. Calcium shouldn't be a problem when doing a Paleo Diet.
Iron
Iron deficiency is associated with lower muscle function and work capacity (study)(study).
Iron could also enhance performance by improving exercise bioenergetics (study).
Due to the cognitive and physical demands of athletes, requirements of iron are higher than for normal population
Animal sources contain heme iron, while plant soures are high in no-heme iron and vitamin C. Heme iron has been proved to be more effective when icreasing serum levels of iron due to its higher absorption (study).
Paleo Diets contain foods of both types. Intake of meat and vegetables should be enough to avoid iron deficiencies.
Antioxidants
Physical exercise generates a higher consumption of oxygen and increases oxidative stress and cell damage.
Higher intakes of antioxidants could provide benefits on muscle function and recovery.
Antioxidants work by delaying muscle fatigue (study), improving glucose uptake (study), and achieving higher degrees of muscle adaptations (study)
Paleo Diets have no problem in fulfilling the requirements of antioxidants, being this primarly vitamins A, C, E.
These vitamins ca be found in fruits, vegetables, eggs, meat and fish.
Cons of Doing a Paleo Diet for Athletes
In principle, Paleo Diets could be used to build muscle and improve your muscle performance. But not everything is pink and amazing...
Paleo Diet is Very Satiating
Paleo Diets are extremely satiating. They are very high in fiber, which are nondegradable and create a gel in our digestive tract (study).
This gel enables us to feel full and satiated before, being able to eat less.
Paleo Diets are also high in protein. This macronutrient has been found to be the most satiating of all three (study).
Athletes trying to gain muscle mass have to eat high amounts of calories daily. And if these are coming from high-fiber or protein sources, it is way harder to reach the required calories.
Paleo Diets are High in Fructose
Paleo Diets are generally high in fructose due to the abundance of fruits. High intakes of fructose may lead to gastrointestinal disorders (study) (study).
The best option for this is to avoid fructose close to your trainings, or consume preferably bananas or any other kind of fruit with low contents of fructose (study)
Paleo Diet has less Adherence
Adherence in Paleo Diets is lower than normal diets.
In this study investigating adherence to Paleo Diet in Australian subjects, researchers found that adherence to the diet was lower when compared to general nutritional habits.
Thi was due to the struggling when doing groceries, and the greater incidence of gastrointestinal problems (study)
Heavy Digestions and Paleo Diets
One of the main problems of Paleo Diet is its high content of foods with a high satiety index and high in fiber.
These two delay digestions and gastric emptying (study).
Paleo Diet also contain high amounts of fats. Fats are associated with longer digestions and gastric emptying due to their high caloric content (study)
Athletes must consume a considerable amount of calories, often doing 6-7 meals a day. If digestions are slow, you will struggle reaching caloric requirements.
Recommendations when doing a Paleo Diet
If you are athlete and want to follow a Paleo Diet, you should consider:
Be Flexible
Adding some 'non-paleo' foods to your diet won't harm anyone.
Base your nutrition on the Paleo Diet and strategically add cereals, or other foods with fast gastric emptying and high carbohydrate content.
Main macronutrient lacking on Paleo Diet is fast digested carbohydrates, making digestiong harder and slower.
Do Paleo Breaks
Once in a while is good to take a break and eat 'at libitum'. It will help achieving higher degrees of adherence and making dieting easier.
You can always go back on track whenever you want, just take the control and don't go crazy when having the breaks.
Use Supplementation
If you are concerned about possible nutritional deficiencies when doing a Paleo Diet, maybe sports supplements are for you.
Vitamin D and multivitaminics seem to be the main possible deficiencies, but it will depend on your situation and context.
Conclusion
In this review we saw how Paleo Diet for athletes can be a feasible protocol to induce muscle adaptations and optimize physcial performance.
However, there are some facts you should consider when following this diet, such as fiber content, gastrointestinal problems or the satiety of the diet.
