Diet References

Description

The Core Diet is the foundational dietary pattern of the Institute for Functional Medicine (IFM). Its goal is to provide a diet rich in minimally processed foods that supports metabolic, cardiovascular, and immune health. It serves as the foundation upon which more specific nutritional interventions may later be applied according to the user's clinical needs.

The Core Diet emphasizes:

• Whole and minimally processed foods
• High nutrient density
• High intake of vegetables and fruits
• High-quality protein
• Healthy fats
• High fiber intake
• Low intake of added sugars
• Diversity of phytochemicals
• Optionally gluten-free and/or dairy-free when clinically indicated.

Although the Core Diet is a model developed by IFM, its nutritional principles are based primarily on the available evidence regarding the Mediterranean dietary pattern, one of the eating patterns with the strongest scientific support for the prevention of chronic disease.

Scientific Evidence

Most of the evidence supporting the Core Diet comes from studies of the Mediterranean diet, currently considered one of the dietary patterns with the strongest level of evidence for the primary and secondary prevention of cardiovascular disease.

The randomized clinical trials PREDIMED and CORDIOPREV demonstrated a significant reduction in major cardiovascular events compared with low-fat diets.

Systematic reviews, meta-analyses, and umbrella reviews show consistent benefits for:

• Cardiovascular disease
• All-cause mortality
• Type 2 diabetes
• Metabolic syndrome
• Inflammatory markers
• Lipid profile
• Glycemic control
• Cognitive function

The evidence is particularly strong for cardiovascular risk reduction and forms the basis of numerous international clinical nutrition guidelines.

Description

The anti-inflammatory diet is an eating pattern designed to support a state of low systemic inflammation through the predominant consumption of foods rich in bioactive compounds and the reduction of foods associated with chronic inflammatory processes. Its goal is to support metabolic, cardiovascular, and immune health, while reducing chronic low-grade inflammation, a mechanism involved in numerous chronic diseases.

This dietary pattern prioritizes:

• A variety of vegetables and fruits, especially those rich in polyphenols and antioxidants.
• Extra-virgin olive oil as the primary source of fat.
• Nuts and seeds.
• Fish rich in omega-3 fatty acids.
• Legumes and whole grains.
• Herbs and spices with antioxidant properties.
• Minimally processed foods.
• At the same time, it limits:
• Ultra-processed foods.
• Added sugars and sugar-sweetened beverages.
• Processed meats.
• Trans fats and highly refined oils.
• Excess refined flours and high-glycemic-load products.

Although several dietary patterns are described as "anti-inflammatory," current scientific evidence shows that the Mediterranean diet is the dietary model with the strongest support for reducing chronic low-grade inflammation in adults.

Scientific Evidence

Evidence from umbrella reviews, systematic reviews, meta-analyses, and randomized clinical trials consistently shows that Mediterranean-style dietary patterns produce the most significant reductions in inflammatory biomarkers such as:

• C-reactive protein (CRP)
• Interleukin-6 (IL-6)
• Interleukin-1β (IL-1β)
• Tumor necrosis factor alpha (TNF-α)
• Other mediators associated with chronic inflammation.

A meta-analysis of 22 randomized clinical trials identified the Mediterranean diet as the dietary pattern associated with the largest reductions in IL-6, IL-1β, and C-reactive protein compared with other dietary patterns evaluated.

Systematic reviews of clinical trials also conclude that this dietary pattern improves multiple inflammatory biomarkers and may contribute favorably to the prevention of cardiovascular disease, type 2 diabetes, and other chronic diseases related to low-grade inflammation.

Although other healthy patterns, such as plant-based diets, DASH, and the Nordic diet, also show beneficial effects, the quality and consistency of the evidence remain stronger for the Mediterranean pattern, which is why it currently represents the reference model for an evidence-based anti-inflammatory diet.

The cardiometabolic diet is an eating pattern designed to improve the primary risk factors associated with cardiovascular and metabolic disease, including obesity, insulin resistance, type 2 diabetes, high blood pressure, dyslipidemia, and metabolic syndrome. Its goal is to optimize glucose and lipid metabolism, support a healthy body weight, and reduce cardiovascular disease risk.

In the Institute for Functional Medicine (IFM) model, the Cardiometabolic Diet represents a modified version of the Mediterranean diet, with an emphasis on foods with a low glycemic impact and high nutrient density. Its main characteristics include:

Predominance of whole and minimally processed foods.

High intake of vegetables, fruits, legumes, and whole grains.

Healthy fats, especially extra-virgin olive oil, nuts, and seeds.

High-quality lean proteins.

High fiber content.

Low intake of added sugars and refined carbohydrates.

Control of glycemic load to support better metabolic control.

Optionally gluten-free and/or dairy-free when clinically indicated.

Scientific Evidence

The highest-quality scientific evidence shows that Mediterranean-style, DASH, low-glycemic-index, and moderately low-carbohydrate dietary patterns are among the best-supported nutritional strategies for improving cardiometabolic health.

Multiple umbrella reviews, systematic reviews, meta-analyses, and randomized clinical trials show consistent benefits for:

Insulin resistance.

Glycated hemoglobin (HbA1c).

Fasting glucose and insulin.

Blood pressure.

Triglycerides.

LDL cholesterol.

Body weight and waist circumference.

Metabolic syndrome.

Overall cardiovascular risk.

The Mediterranean diet has been shown to reduce the risk of developing metabolic syndrome and improve multiple cardiovascular risk factors, while the DASH diet has the strongest evidence for the treatment of high blood pressure. Low-glycemic-index and moderately low-carbohydrate patterns provide additional benefits for glycemic control, particularly in people with type 2 diabetes or insulin resistance.

Together, these strategies form the scientific basis of the cardiometabolic diet used in functional medicine to improve metabolic health and reduce cardiovascular disease risk.

The mitochondrial diet is an eating pattern designed to support the function of mitochondria, the organelles responsible for producing most cellular energy in the form of ATP. Its goal is to optimize energy metabolism, reduce oxidative stress, and support metabolic health through a diet rich in nutrients essential for mitochondrial function.

In the Institute for Functional Medicine (IFM) model, this nutritional strategy incorporates interventions aimed at improving metabolic efficiency and reducing inflammatory burden. Its main characteristics include:

Consumption of foods rich in antioxidants and polyphenols.

Predominance of high-quality healthy fats.

Moderate carbohydrate reduction according to individual needs.

Optional strategies such as time-restricted eating or a ketogenic diet under clinical supervision.

High intake of non-starchy vegetables.

High-quality proteins.

Low glycemic load.

Optionally gluten-free and/or dairy-free when clinically indicated.

Scientific Evidence

There are currently no clinical guidelines supporting a "mitochondrial diet" as an independent dietary pattern. However, available scientific evidence supports several nutritional strategies that promote mitochondrial function and reduce oxidative stress, mechanisms closely related to cellular energy production.

The strongest evidence comes from interventions based on:

Weight loss and controlled calorie restriction, which have been shown to improve mitochondrial respiration, increase ATP production, and reduce the production of reactive oxygen species (ROS).

The Mediterranean dietary pattern, which has the strongest evidence for reducing oxidative stress and chronic inflammation, two processes that directly affect mitochondrial function.

Foods rich in natural antioxidants, polyphenols, and monounsaturated fats, especially extra-virgin olive oil, fruits, vegetables, nuts, and fish.

Human studies show that weight loss through nutritional interventions can improve mitochondrial respiration, increase cellular energy production capacity, and improve insulin sensitivity. Systematic reviews also indicate that the Mediterranean diet reduces multiple biomarkers of oxidative stress and inflammation, creating a favorable metabolic environment for appropriate mitochondrial function.

Certain specific nutrients, such as the combination of glycine and N-acetylcysteine (GlyNAC), coenzyme Q10, polyphenols, and other antioxidants, show promising results in clinical studies; however, the evidence remains limited and does not support recommending their widespread use as part of a dietary pattern for the general population.

Overall, the best available scientific evidence supports a Mediterranean-style dietary pattern, together with body-weight management and a diet rich in plant foods and antioxidants, as the nutritional strategy with the greatest potential to support mitochondrial health.

Description

The Low FODMAP Diet is a nutritional strategy designed to temporarily reduce the intake of certain fermentable short-chain carbohydrates known as FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). These molecules may be incompletely absorbed in some people and may promote gas production, intestinal distention, and water movement into the intestine, which can trigger digestive symptoms.

This intervention is primarily indicated for people with Irritable Bowel Syndrome (IBS) and selected other functional gastrointestinal disorders. It is not intended to be a permanent diet, but rather a structured protocol that should be carried out under the supervision of a health professional.

The intervention consists of three phases:

• Temporary restriction, eliminating foods high in FODMAPs.
• Gradual reintroduction, to identify which FODMAP groups cause symptoms and in what amounts.

Personalization, establishing the most varied diet possible while restricting only the foods that actually cause symptoms.

This approach helps control digestive symptoms while preserving nutritional quality and avoiding unnecessary long-term restriction.

Scientific Evidence

The Low FODMAP Diet is currently the dietary intervention with the strongest scientific support for the nutritional management of Irritable Bowel Syndrome (IBS).

Multiple systematic reviews, meta-analyses, and randomized clinical trials show that this strategy significantly improves:

• Overall gastrointestinal symptoms.
• Abdominal bloating.
• Abdominal pain.
• Irritable bowel syndrome severity.
• Health-related quality of life associated with digestive health.

A systematic review with network meta-analysis concluded that the low FODMAP diet was the nutritional intervention with the best results for overall relief of IBS symptoms compared with other dietary strategies.

Major international gastroenterology guidelines recommend its use when general dietary and lifestyle measures are not sufficient to control symptoms.

However, evidence also shows that strict FODMAP restriction should not be maintained for prolonged periods because it may reduce the abundance of beneficial bacteria such as Bifidobacteria and decrease dietary diversity. Therefore, the reintroduction and personalization phases are essential parts of treatment.

There is currently emerging evidence of benefit in some patients with inflammatory bowel disease in remission who experience functional symptoms similar to irritable bowel syndrome, although most of the evidence continues to focus on patients with IBS.

The anti-Candida diet is an eating pattern used within the Institute for Functional Medicine (IFM) model as a personalized nutritional strategy for people with gastrointestinal symptoms, alterations in the intestinal microbiota, or risk factors that may promote dysbiosis. Its goal is to promote an eating pattern based on minimally processed foods and reduce dietary factors associated with imbalance in the intestinal ecosystem.

In the IFM model, this dietary pattern is characterized by:

• Low intake of simple sugars.
• Reduction of refined carbohydrates.
• Predominant consumption of non-starchy vegetables.
• High-quality protein.
• Healthy fats.
• High nutrient density.
• Individualized identification of possible trigger foods.
• Promotion of a healthy intestinal microbiota.

Assignment of this dietary pattern is part of an individualized nutritional assessment process and is adapted to each user's clinical needs, symptoms, medical history, and health goals.

Scientific Evidence

There is currently no high-quality scientific evidence supporting the anti-Candida diet as a specific dietary pattern for preventing or treating candidiasis.

Available systematic reviews and clinical guidelines conclude that:

• There is no specific diet recommended for the treatment or prevention of recurrent candidiasis.

Restricting sugars or refined carbohydrates has not been shown in controlled clinical trials to reduce Candida colonization or prevent recurrence.

Treatment of candidiasis should be based on appropriate diagnosis and, when indicated, antifungal therapy.

The nutritional evidence with the strongest support relates to the use of probiotics as an adjunct to antifungal treatment in women with recurrent vulvovaginal candidiasis. Studies show improvement in short-term clinical cure and a reduction in recurrence; however, the overall certainty of the evidence remains low, and clinical guidelines consider that there is still insufficient evidence to recommend routine use.

Therefore, this dietary pattern should be understood as a healthy eating strategy intended to support balance in the intestinal microbiota, and not as a specific treatment for Candida infection.

Description

The elimination diet is a nutritional strategy used to identify foods that may contribute to the onset or worsening of digestive, skin, or systemic symptoms in susceptible individuals. It consists of temporarily removing certain foods or food groups, followed by structured reintroduction to evaluate individual tolerance.

In the Institute for Functional Medicine (IFM) model, the Elimination Diet is part of a personalized nutrition process and is characterized by:

• Temporary elimination of potentially triggering foods.
• A diet based on whole and minimally processed foods.
• High nutrient density.
• Abundant intake of vegetables and fruits.
• High-quality proteins.
• Healthy fats.
• Reduction of ultra-processed foods.
• Systematic reintroduction of eliminated foods.
• Personalization of the dietary pattern according to the individual's clinical response.

The primary goal is to identify foods that may be associated with specific symptoms while avoiding unnecessary long-term restrictions.

Scientific Evidence

Elimination diets have scientific evidence for specific clinical indications, although the strength of the evidence varies by condition.

The strongest evidence applies to:

Irritable Bowel Syndrome (IBS): the low FODMAP diet is currently the elimination strategy with the strongest scientific support for reducing abdominal pain, bloating, symptom severity, and improving quality of life. The American Gastroenterological Association (AGA) considers it the dietary intervention with the strongest evidence for the nutritional management of IBS.

Eosinophilic esophagitis (EoE): empirical elimination diets have been shown to induce histologic remission in approximately 54–61% of patients, making them one of the main non-pharmacologic treatment alternatives.

In other conditions, such as identifying food sensitivities through diets guided by IgG antibodies or other biomarkers, the evidence remains limited and heterogeneous. Although some clinical trials show benefits in certain patients, systematic reviews and clinical guidelines currently conclude that there is insufficient evidence to recommend routine use.

Therefore, the Elimination Diet should be carried out in a structured way, under the supervision of a health professional, and should always include a reintroduction phase to identify individual tolerance and reduce the risk of unnecessary nutritional restriction.