Complete Guide to Food Intolerances

Luis Isaías provides a comprehensive guide to food intolerances, their impact on athletes and how to effectively address them.

In the world of sports nutrition, understanding food intolerances is essential to help athletes reach their peak performance. 

These intolerances can negatively affect health and sports performance.

This is why a sports nutritionist, who recognizes the  importance of the nutritional plan in cases of intolerance, is crucial.

Guide To Food Intolerances

What are food intolerances?

They are adverse reactions to certain foods due to the body’s inability to digest or metabolize certain components. 

This is due to the deficiency or absence of certain digestive enzymes. 

These are reactions that occur when the individual’s digestive health has difficulty processing certain components present in food.

Unlike food allergies, which involve an immune system response, food intolerances are usually the result of a deficiency or absence of certain digestive enzymes.

Common food intolerances

One of these is lactose intolerance, which occurs due to a deficiency of lactase, the enzyme needed to break down the sugar present in milk and dairy products. 

Another well-known food intolerance is gluten intolerance, which is found in foods such as wheat, barley and rye. 

This intolerance, known as celiac disease, is characterized by an autoimmune reaction to gluten that damages the lining of the small intestine.

In addition to lactose and gluten, there are other less common food intolerances, such as intolerance to sulfites.

These are found in processed foods and alcoholic beverages, and intolerance to certain food additives, such as monosodium glutamate (MSG). 

These intolerances can cause uncomfortable gastrointestinal symptoms, such as bloating, gas, diarrhea and upset stomach.

Are they the same for everyone?

It is important to note that food intolerances vary in their severity and in the amount of food needed to trigger symptoms.

Some people may experience symptoms only when consuming large amounts of the problematic food, while others may experience symptoms even with small amounts.

Identifying food intolerances requires an individualized approach and assessment of each person’s specific symptoms. 

Sports nutritionists play a key role in this process, working in collaboration with other healthcare professionals.

This includes clinical testing, blood work and controlled elimination of suspect foods from the diet.

This controlled elimination approach is critical in identifying specific intolerances and developing an appropriate dietary plan for the affected athlete.

Impact on athletic performance

sports nutrition Luis Isaías

Food intolerances can significantly impact athletic performance. 

Malabsorption of essential nutrients can lead to nutritional deficiencies and decreased energy available for exercise. 

In addition, gut troubles such as bloating, diarrhea and stomach upset can affect comfort and concentration during training or competition.

Identification and diagnosis

A thorough evaluation is essential to identify food intolerances in athletes. 

This may include a combination of clinical testing, blood testing, and controlled elimination of suspect foods. 

An interdisciplinary approach with other health care professionals, such as allergists or gastroenterologists, may be beneficial for accurate diagnosis.

Dietary Strategies for Athletes with Food Intolerances

Once intolerances are identified, it is crucial to develop a dietary plan tailored to the individual needs of each athlete. 

Sports nutritionist Luis Isaias shares some strategies that can help:

Controlled elimination.

Completely eliminate problem foods from the diet and watch for changes in symptoms and performance. 

This requires a careful approach to ensure essential nutrients are maintained.

Appropriate substitutions

Seek suitable alternatives for the eliminated foods, ensuring that the athlete’s specific nutritional requirements are met. 

For example, lactose-intolerant athletes may opt for calcium sources such as green leafy vegetables and fortified products.

Food Intolerances Luis Isaías


In some cases, supplements may be necessary to compensate for nutritional deficiencies. 

However, it is important to work closely with the athlete and a registered dietitian to ensure that appropriate and safe supplementation is selected.

Education and support

It is essential to educate athletes about food intolerances and how to manage them appropriately. 

Providing information on food labeling, meal choices and strategies to avoid potential cross-contamination is critical. 

In addition, offering emotional support can help athletes cope with dietary restrictions and maintain motivation.

Food intolerance counseling from a nutritionist

When dealing with food intolerances in the sports context, having the support of a specialized nutritionist is of vital importance. 

A sports nutritionist has the knowledge and experience to identify and address intolerances.

He or she can also optimally adapt the diet to meet the individual nutritional needs of athletes.

The sports nutritionist can perform a thorough assessment of the athlete’s health status and athletic performance, allowing him or her to design a personalized dietary plan that minimizes nutritional deficiencies and maximizes performance. 

In addition, the nutritionist can provide ongoing education and guidance to the athlete, allowing them to better understand their intolerances.


Nutritionist Luis Isaías provides a comprehensive guide to food intolerances, their impact on athletes and how to effectively address them.

From the above text we can draw the following conclusions:  

  • Understanding food intolerances and their impact on sports performance is of utmost importance;
  • they can have a significant impact on athletic performance;
  • Properly identifying and addressing these intolerances can help athletes reach their full potential and maintain optimal health; 
  • With the proper support from a sports nutritionist, athletes can learn to manage and overcome these challenges.