Natalia Úbeda

Introduction: Nutrition plays a fundamental role in sports performance by influencing energy availability, recovery, and training adaptation. In recent years, different dietary strategies have gained popularity among athletes, although the evidence supporting their efficacy is inconsistent. Objective: This consensus document, developed under the auspices of the Spanish Society of Nutrition, aims to provide a critical overview of the most relevant nutritional strategies currently used in sports and to offer evidence-based practical recommendations for both professional and recreational athletes, coaches, and health professionals. Methods: A narrative review was conducted following standardized scientific procedures by a multidisciplinary panel of experts. The analyzed strategies included high-carbohydrate, low-carbohydrate, ketogenic, intermittent fasting, plant-based, Paleolithic, and carbohydrate periodization diets. Each strategy was assessed based on its physiological rationale, evidence of performance in endurance, strength/power, sprint, aesthetic, weight category, and team sports, practical applications, and potential risks. Results: The available evidence shows that no single dietary strategy can be universally recommended for all athletes. High carbohydrate availability remains the most consistent approach for sustaining performance in endurance and high-intensity efforts. Low-carbohydrate and ketogenic diets enhance fat oxidation but often compromise exercise economy at competitive intensity levels. Intermittent fasting may improve body composition and metabolic health; however, it requires careful adaptation. Well-planned plant-based diets can support performance, although attention to certain nutrients (e.g., B12, iron, and omega-3) is essential. Paleolithic diets improve metabolic parameters but show limited direct evidence of athletic performance. Carbohydrate periodization is a promising tool for combining metabolic adaptations with competitive demands. Conclusions: Nutritional strategies should be individualized according to the athlete’s sport, training phase, and personal context. Professional guidance is crucial for minimizing risks and optimizing benefits. Further well-designed, long-term studies on athletes are needed to resolve the current controversies.

Background/Objectives: Celiac disease (CD) is an autoimmune disorder characterized by small intestinal enteropathy triggered by gluten ingestion, often associated with gut dysbiosis. The most effective treatment is strict adherence to a gluten-free diet (GFD), which alleviates symptoms. This study uniquely integrates taxonomic, functional, and resistance profiling to evaluate the gut microbiota of women with CD on a GFD. Methods: To evaluate the long-term impact of a GFD, this study analyzed the gut microbiota of 10 women with CD on a GFD for over a year compared to 10 healthy controls with unrestricted diets. Taxonomic diversity (16S rRNA gene sequencing and the analysis of α and β-diversity), metabolic functionality (Biolog EcoPlates^®), and antibiotic resistance profiles (Cenoantibiogram) were assessed. Results: Metagenomic analysis revealed no significant differences in taxonomic diversity but highlighted variations in the abundance of specific bacterial genera. Women with CD showed increased proportions of Bacteroides, Streptococcus, and Clostridium, associated with inflammation, but also elevated levels of beneficial genera such as Roseburia, Oxalobacter, and Paraprevotella. Despite no significant differences in metabolic diversity, higher minimum inhibitory concentrations (MICs) in women in the healthy control group suggest that dietary substrates in unrestricted diets may promote the proliferation of fast-growing bacteria capable of rapidly developing and disseminating antibiotic resistance mechanisms. Conclusions: These findings indicate that prolonged adherence to a GFD in CD supports remission of gut dysbiosis, enhances microbiota functionality, and may reduce the risk of antibiotic resistance, emphasizing the importance of dietary management in CD.

The absence of gluten is a technological challenge that requires the addition of components to replace the unique viscoelastic properties of gluten, thus altering the nutritional composition of gluten-free (GF) breads. Moreover, GF flours may have different compositions as compared to gluten-containing (GC) counterparts because of a different origin. This may impact the nutritional quality of GF diets. The aim of the study is to provide updated analytical data on moisture, fat, and fibre contents in GF flour and bread samples, and compare them with their GC counterparts, as well as to analyse ingredients and how they impact nutritional quality. A total of 30 different flours and 24 types of bread were analysed using AOAC methods. GF cereal flours contain more fat than GC flours (3.5 ± 2.1% vs. 2.5 ± 2.1%, p < 0.001), as well as GF flours from pseudocereals, except for wholemeal buckwheat (2.6 ± 0.1%). Fibre content is lower in GF flours (3.6 ± 3.1% vs. 7.1 ± 3.9%, p = 0.03), except for GF pseudocereal and legume flours. GF breads contain almost twice as much fat 6.6 ± 2.3% vs. 1.4 ± 0.2%, p < 0.001, and 4.2 ± 1.2%, p < 0.001) and fibre (7.3 ± 2.4% vs. 2.8 ± 0.5%, p < 0.001, and 4.9 ± 2.1%, p = 0.002) as GC breads. This is due to the raw materials themselves and to the addition of ingredients, such as regular and high oleic sunflower oil, and psyllium. Fibre ingredients and additives are more frequently used in ready-to-eat GF flours and breads, and more GF breads also contain fat-based ingredients, as compared to GC. Amaranth and chickpea flours are good alternatives to produce breads with better nutritional quality. Analysis of GF products for critical nutrients is peremptory because of continuing technological and nutritional innovation.

Celiac disease (CD) is an autoimmune disorder characterized by small intestinal enteropathy triggered by gluten ingestion, often associated with gut dysbiosis. The most effective treatment is strict adherence to a gluten-free diet (GFD), which alleviates symptoms. To evaluate the long-term impact of GFD, this study analyzed the gut microbiota of 10 women with CD on a GFD for over a year compared to 10 healthy controls with unrestricted diets. Taxonomic diversity (16S rRNA gene sequencing and the analysis of α and β-diversity), metabolic functionality (Biolog EcoPlates®), and antibiotic resistance profiles (Cenoantibiogram) were assessed. Metagenomic analysis revealed no significant differences in taxonomic diversity but highlighted variations in the abundance of specific bacterial genera. Women with CD showed increased proportions of Bacteroides, Streptococcus, and Clostridium, associated with inflammation, but also elevated levels of beneficial genera such as Roseburia, Oxalobacter, and Paraprevotella. Despite no significant differences in metabolic diversity, higher minimum inhibitory concentrations (MICs) in women in the healthy control group suggest that dietary substrates in unrestricted diets may promote the growth of fast-growing bacteria capable of rapidly developing and disseminating antibiotic resistance mechanisms. These findings indicate that prolonged adherence to a GFD in CD supports remission of gut dysbiosis, enhances microbiota functionality, and may reduce the risk of antibiotic resistance, emphasizing the importance of dietary man agement in CD.

Background/Objectives: Aeronautical military personnel operate under intense physical and mental stress, requiring high psychophysical aptitude. Adequate nutrition is essential to sustain operational readiness and mitigate the risk of chronic diseases and other health issues. This study aims to evaluate the nutritional status of aeronautical military personnel group in Spain through dietary parameters. Methods: A total of 390 male aeronautical military personnel, who attended the Centro de Instrucción de Medicina Aeroespacial (Madrid, Spain), were evaluated. Energy and nutrient intakes were estimated by three non-consecutive 24-h dietary recalls (DIAL^® program). Results: The median energy intake was 2134 kcal/day, with significant variations across professional groups, highest in parachutists (2347 kcal/day). Protein intake was 18.2% TE, while carbohydrate intake was 37.6% TE, below standards, with 83.8% of participants not meeting the EFSA guidelines. However, a high intake of added sugars was observed (10% TE). Fat intake (38.3% TE) and saturated fats (11.7% TE) exceeded recommendations. Micronutrient deficiencies were notable for vitamin D (98% below recommendations), folate (56.4%), vitamin C (40.2%), calcium (50.3%), iodine (76.6%), and zinc (59%). Elevated cholesterol intake (352 mg/day) and inadequate fiber intake (18.5 g/day) were also observed. Conclusions: This study highlights imbalanced dietary patterns among Spanish aeronautical military personnel, with high protein, fat, cholesterol and added sugar consumption, low carbohydrate, and inadequate intake of critical micronutrients and fiber. These findings emphasize the need for targeted dietary interventions, nutritional monitoring protocols, and specific guidelines to enhance health and performance in this specialized group.

Eating a nutritionally balanced breakfast can be a challenge when following a gluten-free diet (GFD). We assessed the ingredients and nutrient composition of 364 gluten-free breakfast products (GFPs) and 348 gluten-containing counterparts (GCCs), and we analysed the nutritional quality of breakfast in a group of Spanish children and adolescents with celiac disease (CD) (n = 70), as compared to controls (n = 67). Food intakes were estimated using three 24 h dietary records. The composition of GFPs and GCCs was retrieved from the package labels of commercially available products. Most participants (98.5%) ate breakfast daily, and only one person in each group skipped breakfast once. The breakfast contribution of the total daily energy was 19% in participants with CD and 20% in controls. CD patients managed a balanced breakfast in terms of energy (54% from carbohydrates; 12% from proteins; 34% from lipids) and key food groups (cereals, dairy, fruits), but their intake of fruits needs improvement. Compared to controls, breakfast in the CD group provided less protein and saturated fat, a similar amount of carbohydrates and fibre, and more salt. Fibre is frequently added to GFPs, but these contain less protein because of the flours used in formulation. Gluten-free bread contains more fat and is more saturated than is GCC. Sugars, sweets, and confectionery contribute more to energy and nutrient intakes in participants with CD, while grain products do so in controls. Overall, breakfast on a GFD can be adequate, but can be improved by GFPs reformulation and a lower consumption of processed foods.

Gluten-free products (GFP) are a good choice for the replacement of cereals when following a gluten-free diet due to celiac disease (CD). However, commercial GFP are made with highly refined flours and may contain more fat, sugar, and salt, and less fiber and micronutrients than gluten-containing analogues, thus challenging the nutritional adequacy of the diet. The aim of this study is to assess the contribution of GFP to the diets of children and adolescents with CD. Food intakes were assessed in a cross-sectional study on 70 children and adolescents with CD (aged four to 18, 50% females), using three 24-h dietary records. GFP consumption reached 165 g a day and comprised mostly bread and fine bakery ware, followed by pasta. GFP contributed with a high percentage (>25%) to total energy, carbohydrates, fiber, and salt daily intakes and, to a lesser extent (<20%), to fat (including saturated fat), sugars and protein. Contribution of homemade products was testimonial. GFP contribution to total energy intake is significant and, consequently, relevant to the nutritional adequacy of the diet. Children and adolescents with CD could benefit from fat, saturated fat, and salt reduction, and fiber enrichment of processed GFP.

Combat sports athletes competing in the same discipline exhibit notable and substantial differences in body weight, body composition (BC) and adiposity. No studies have considered the influence of adiposity levels in the agreement between different BC assessment methods. The aim of this study was to analyze the influence of adiposity in the agreement between different methods used to estimate relative body fat (%BF) in Olympic combat sport athletes. A total of 38 male athletes were evaluated using air displacement plethysmography and dual-energy X-ray absorptiometry (DXA) as laboratory methods, and bioelectrical impedance analysis (BIA), near-infrared interactance (NIR) and anthropometry as field methods. All methods were compared to DXA. Agreement analyses were performed by means of individual intraclass correlation coefficients (ICCs) for each method compared to DXA, Bland–Altman plots and paired Student t-tests. The ICCs for the different methods compared to DXA were analyzed, considering tertiles of %BF, tertiles of body weight and type of sport. For the whole group, individual ICCs oscillated between 0.806 for BIA and 0.942 for anthropometry. BIA showed a statistically significant underestimation of %BF when compared to DXA. The agreement between every method and DXA was not affected by %BF, but it was highest in athletes at the highest %BF tertile (>13%). The ICC between NIR and DXA was poor in 72–82 kg athletes. Our results indicate that field methods are useful for routine %BF analysis, and that anthropometry is particularly appropriate, as it showed the highest accuracy irrespective of the athletes’ adiposity.

To determine the influence of different doses of maximal acute exercise on the kinetics of plasma homocysteine (tHcy) and its relationship with oxidative status and vascular function, nine recreational runners completed a 10 km race (10K) and a marathon (M). Blood samples were collected before (Basal), immediately post-exercise (Post0), and after 24 h (Post24). Nutritional intake was controlled at each sample point. A significant increase in tHcy was observed after both races, higher after M. Basal levels were recovered at Post24 after 10K, but remained elevated at Post 24 for M. A significant decrease in GSH/GSSG ratio was observed in Post0, especially marked after M. Furthermore, this increase in pro-oxidant status remained at Post24 only after M. Other oxidative status markers failed to confirm this exercise-induced pro-oxidant status except glutathione peroxidase activity that was lower in Post24 compared to Basal in 10K and in Post0 and Post24 in M. No statistical correlation was found between oxidative markers and tHcy. No significant changes were observed in the concentration of endothelial cell adhesion molecules (VCAM-1 and E-Selectin) and VEGF. In conclusion, tHcy increases in an exercise–dose–response fashion but is not related to endothelial dysfunction mediated by oxidative stress mechanisms.