Metabolic Impact on the Mitochondria-gut Microbiota Axis of Failure to Follow Restrictive Dietary Interventions in Subjects Living With Obesity

The study consists of an open-label randomized controlled clinical trial. The selected subjects will be men or women over 18 years of age with a body mass index (BMI) greater than or equal to 30 kg/m2, who meet the selection criteria, the subjects who will be randomly assigned to one of 3 dietary intervention groups. The study consisted of a dietary intervention with a duration of 8 weeks and a follow-up of 24 weeks after dietary intervention.

The intervention groups will be as follows:

• Calorie-restricted diet: Dietary recommendations will be given restricting 30% in energy (kcal) according to their usual diet with normal macronutrient distribution (20-30% protein, 50-60% carbohydrates, 20-30% fats).
• Intermittent fasting diet: Dietary recommendations will be given according to the energy expenditure determined by indirect calorimetry with normal macronutrient distribution. Intermittent fasting will be used with a time-restricted model of 16:8. For 16 hours, they will not be able to eat or drink calories. In the other 8 hours, they need to adhere to the energy-restricted diet.
• Ketogenic diet: Recommendation will be given according to the energy expenditure determined by indirect calorimetry, with the following distribution of macronutrients: 20-25% protein, 5-10% carbohydrates, 70-80% fat.

Participants with calorie-restriction, intermittent fasting, or ketogenic diet dietary intervention will be provided with a food menu guide for fifteen days. After 8 weeks of the assigned intervention, patients will be provided with general dietary recommendations and will be invited to three more follow-up visits at 8, 16 and 24 weeks post-intervention. In addition, all participants will be provided with general recommendations for a physical activity plan for people living with obesity.

To evaluate adherence to treatment, participants will be asked to fill out 2 logbooks every two weeks (1 during the week and 1 for the weekend) in which they must record the type, amount and place where they consumed the food at each feeding time. They will also be called once a week for a 24-hour reminder. Participants on the ketogenic diet will be given test strips to measure ketones in urine.

Inclusion criteria

• Male and female.
• Adults >18 years of age.
• BMI ≥ 30 kg/m2

Exclusion criteria

• Patients with any type of diabetes.
• Patients with high blood pressure.
• Patients with acquired diseases secondarily producing obesity and diabetes.
• Patients who have suffered a cardiovascular event.
• Patients who at the screening visit presented glucose values greater than 126 mg/dL, triglycerides greater than 350 mg/dL, cholesterol greater than 300mg/dL and/or creatinine greater than 1.2 mg/dL in men and greater than 1 mg/dL in women.
• Patients with gastrointestinal diseases.
• Weight loss > 3 kg in the last 3 months.
• Catabolic diseases such as cancer and acquired immunodeficiency syndrome.
• Pregnancy status.
• Positive smoking.
• History of major surgery requiring general or regional anesthesia, respiratory support, and involving a recovery time longer than 2 weeks, such as surgeries of the abdomen (bowel resection), chest, head, and neck.
• Diagnosis of Anxiety and Depression as Determined by the HADS Scale
• Drug treatment:
• Antihypertensive drugs or treatment
• Treatment with hypoglycemic agents or insulin and antidiabetic drugs.
• Treatment with statins, fibrates or other drugs to control dyslipidemia.
• Use of antibiotics in the three months prior to the study.
• Use of steroid drugs, chemotherapy, immunosuppressants, or radiation therapy.
• Anorexigenic or that accelerate weight loss such as sibutramine or orlistat.
• Supplements with any of the functional foods used in the study.
• Probiotic, prebiotic or symbiotic supplements.