An interventional study of Calorie restriction and Intermittent fasting 16/8 in Obesity, sponsored by Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. Completed at 2 sites in Mexico. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-03-27.
Sponsored by Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran · Not applicable, Interventional, and Treatment
Nutritional interventions with dietary restrictions have become highly popular for promoting weight and body fat loss; In addition, they are largely associated with the improvement and preservation of mitochondrial function as well as the changes they generate in the composition of the gut microbiota and microbial metabolites. During obesity, mitochondrial dysfunction in monocytes can increase low-grade inflammation and contribute to alterations in various metabolic tissues. There have been many studies that have been dedicated to describing the benefits and mechanisms of the use of restrictive interventions, but few have focused on further monitoring and evaluating the metabolic changes that occur due to the lack of follow-up of the use of these interventions, where subjects resume eating patterns with energy overload. behavior that happens in the vast majority of patients, so keeping mitochondria in good condition is a key aspect of maintaining health. The present project aims to study the metabolic changes that are generated by the lack of follow-up of restrictive dietary interventions, focusing on the effects produced in mitochondrial function evaluated in monocytes isolated from peripheral blood and the impact that the composition of the intestinal microbiota is generated from the metabolites produced, affecting as a consequence the inflammatory state of the host. A randomized controlled clinical trial will be carried out where the selected participants will be assigned by lottery to one of the 3 nutritional interventions for 8 weeks, then the participants will be followed up at 8, 16 and 24 weeks after the intervention has ended. Anthropometric and biochemical parameters, resting energy expenditure, blood pressure, oxidative stress markers, metabolomics, gut microbiota composition, and mitochondrial function will be evaluated during follow-up.
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:
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.
6,296 studies on the registry are indexed under Obesity; 1,692 are open to participants now.
This study's enrollment of 84 is close to the median of 78 across 4,878 interventional studies indexed under Obesity.
Browse Obesity studies →Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran is the lead sponsor of 141 studies on the registry; 17 are open to participants now.
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Exclusion Criteria:
Participants will be provided with a food menu guide for fifteen days with a 30% energy restriction (kcal) according to their usual diet, with a macronutrient distribution of 20-30% protein, 50-60% carbohydrates and 20-30% fat.
Other: Calorie restriction
Participants will be provided with a food menu guide for fifteen days with an energy intake according to the energy expenditure determined by indirect calorimetry with normal distribution of macronutrients. 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.
Other: Intermittent fasting 16/8
Participants will be provided with a food menu guide for 15 days with an energy intake according to the energy expenditure determined by indirect calorimetry, with the following distribution of macronutrients: 20-25% protein, 5-10% carbohydrates, 70-80% fat.
Other: Ketogenic diet
Participants will be provided with a food menu guide for fifteen days with a 30% energy restriction (kcal) according to their usual diet, with a macronutrient distribution of 20-30% protein, 50-60% carbohydrates and 20-30% fat.
Participants will be provided with a food menu guide for fifteen days with an energy intake according to the energy expenditure determined by indirect calorimetry with normal distribution of macronutrients. 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.
Participants will be provided with a food menu guide for 15 days with an energy intake according to the energy expenditure determined by indirect calorimetry, with the following distribution of macronutrients: 20-25% protein, 5-10% carbohydrates, 70-80% fat.
Mitochondrial function
Change in mitochondrial function determined by measuring the oxygen consumption rate (OCR) in isolated monocytes
Time frame: baseline to 8, 16, 24 and 32 weeks
Gut microbiota composition
Change in gut microbiota composition determined by bacterial abundance obtained after taxonomy assignment.
Time frame: baseline to 8, 16 and 32 weeks
Body weight measurement
Change in body weight determined by scale.
Time frame: baseline to 8, 16, 24 and 32 weeks
Glucose concentration
Change in glucose in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
Cholesterol concentration
Change in cholesterol in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
HDL cholesterol concentration
Change in HDL cholesterol in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
LDL cholesterol concentration
Change in LDL cholesterol in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
Triglycerides concentration
Change in triglycerides in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
Insulin concentration
Change in insulin in the serum determined by ELISA kit.
Time frame: baseline to 8, 16, 24 and 32 weeks
Leptin concentration
Change in leptin in the serum determined by ELISA kit.
Time frame: baseline to 8, 16, 24 and 32 weeks
Interleukins concentration
Change in interleukins in the serum determined by ELISA kit.
Time frame: baseline to 8, 16, 24 and 32 weeks
C-reactive protein concentration
Change in C-reactive protein in the serum determined by autoanalyzer.
Time frame: baseline to 8, 16, 24 and 32 weeks
TNF-a concentration
Change in TNF-a in the serum determined by ELISA kit.
Time frame: baseline to 8, 16, 24 and 32 weeks
Alpha diversity of gut microbiota
Shanon index to indicate alpha diversity of gut microbiota from the feces
Time frame: baseline to 8, 16 and 32 weeks
Beta diversity of gut microbiota
Principal component analysis to indicate alpha diversity of gut microbiota from the feces
Time frame: baseline to 8, 16 and 32 weeks
Fat mass percentage
Fat mass percentage determined by multifrequency electrical bioimpedance.
Time frame: baseline to 8, 16, 24 and 32 weeks
Lean mass percentage
Lean mass percentage determined by multifrequency electrical bioimpedance.
Time frame: baseline to 8, 16, 24 and 32 weeks
Skeletal muscle mass percentage
Skeletal muscle mass percentage determined by multifrequency electrical bioimpedance.
Time frame: baseline to 8, 16, 24 and 32 weeks
Change of metabolites in serum
Change of metabolites in serum determined by un-targeted metabolomics using Liquid chromatography/ Mass spectrometry analysis (LC/MS).
Time frame: baseline to 8, 16 and 32 weeks
Change of metabolites in feces
Change of metabolites in feces determined by un-targeted metabolomics using Liquid chromatography/ Mass spectrometry analysis (LC/MS).
Time frame: baseline to 8, 16 and 32 weeks
Determination of valvular function
Doppler venous ultrasound will be performed with the MX7 equipment of the Shenzhen Mindray Bio-Medical Electronics Co., LTD to determine the valvular function of the great saphenous vein, small saphenous vein, junction femoral saphenous vein, femoral vein, popliteal vein, measuring their dimensions and the level of venous reflux.
Time frame: baseline to 8 weeks
Plan to share: No — Data may be shared after publication.
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran