The purpose of this research is to test the hypothesis that the consumption of meat products without additives, in comparison with their analogues with additives, could be beneficial in terms of modifying health markers. A 5-week clinical trial with two parallel arms will be performed with two parallel arms. Changes in different serum biomarkers of lipid metabolism, glucose, oxidative stress and inflammation will be analysed. Biomarkers related to digestive health, such as short chain fatty acid (SCFA) production and impact on the gut microbiota, will also be evaluated. Finally, factors such as body mass index (BMI), body fat percentage and markers of exposure to additives will be measured.

One of the most discussed reasons for reducing meat consumption is its additive content. Additives are compounds added to food products to preserve their technological properties, to avoid contamination by microorganisms, regulate acidity, and even act as thickeners, emulsifiers, and stabilisers. However, there is some controversy over the actual health effects of additives in meat products, as their long-term effect has not been studied for many of them. On the other hand, not all additives have the same effect, as for antioxidants such as sodium citrate (E-331) and sodium erythorbate (E-316), as well as acidity regulators such and triphosphates (E-451) no side effects or significant toxicity have been reported on healthy individuals. However, other additives such as carrageenans (E-407) have been associated with intestinal inflammation and inflammatory bowel diseases by several animal studies. Negative effects have also been found for sodium nitrite (E-250), which can lead to the formation of carcinogenic N-nitrosamines.

Due to the rising concern about additives in meat products, it is of particular interest to identify the possible health effects of a processed meat product without additives and allergens. Therefore, the hypothesis of this study is that the production of additive-free meat products may be of interest to the consumers and may have a beneficial effect on their health.

To confirm this hypothesis, two meat products without additives or allergens were produced (cooked ham and cooked turkey breast), and a double-blind, randomised, controlled, unicentric trial with two parallel arms will be conducted.

Prior to the start of the intervention period (baseline time) anthropometric measurements and blood, faeces and urine samples will be taken. 58 participants will take alternately 100g of cooked ham or cooked turkey breast (control or reformulated depending on the group) 6 days a week for 5 weeks, noting the rest of their diet in a collection notebook that they will then give to the researchers. After the intervention (final time), anthropometric measurements and blood, faeces and urine samples will be taken again.

Inclusion Criteria:

• Subjects of both sexes (men or women) between 18 and 65 years of age
• Body mass index between 18.5 and 30 Kg / m^2.

Exclusion Criteria:

• Diabetes mellitus, chronic kidney disease, liver disease, infectious diseases or any type of cancer.
• Eating disorders, intestinal or similar problems.
• Subjects in treatment with medication for hypertension or hyperlipaemia.
• Subjects in treatment with antibiotics in the last 3 months.
• Subjects who have ingested pre- or probiotic supplements.
• Subjects who have ingested omega-3 or omega-6 supplements.
• Patients undergoing major surgery in the last 3 months prior to the beginning of the study.
• Subjects who have donated blood in the last month prior to the beginning of the study.
• Subjects with alcohol abuse, or with excessive alcohol consumption.
• Vegetarian subjects.
• Pregnant women.
• Smokers.
• Participation in other clinical trials in the last 3 months.