Overview
The main objective of this intervention study is to evaluate the effect of satiating protein and/or fiber bar consumption on weight loss and other osteoarticular and cardiometabolic parameters related to excess weight in subjects with overweight or obesity.
To achieve this objective, volunteers will be instructed to consume three bars per day as part of a hypocaloric diet, in accordance with healthy nutritional guidelines, over a 12-week period.
The main questions to answer are:
- Does the regular consumption of these protein and/or fiber bars help to lose weight?
- Does the regular consumption of these protein and/or fiber bars help to improve the osteoarticular health?
- Does the regular consumption of these protein and/or fiber bars help to improve the cardiometabolic health?
The specific objectives are focused on evaluating the effects of the intervention on the following parameters:
- Weight and body composition.
- Knee joint range of motion.
- Blood biomarkers related to collagen degradation and synthesis, associated with osteoarticular health.
- Glycemic and lipid profiles, blood pressure, and biomarkers of kidney, liver, cardiovascular, and inflammatory health.
- Changes in joint discomfort (improvement or worsening).
- Adherence to the assigned intervention, including both dietary compliance and intake of the study-provided supplement.
- Satiety-related variables assessed using a visual analog scale (VAS).
- Urinary hydroxyproline and stool samples for metagenomic analysis.
- Gastrointestinal health, mental health, quality of life, and physical activity level assessed through validated questionnaires.
Target sample size is 144 subjects and participants will be allocated in four different groups:
- Group 1 (n=36): hypocaloric diet + protein and fiber supplement.
- Group 2 (n=36): hypocaloric diet + protein and fiber supplement.
- Group 3 (n=36): hypocaloric diet + fiber supplement.
- Group 4 "Placebo group" (n=36): hypocaloric diet + placebo supplement. Participants will attend the nutritional intervention unit at weeks 1, 8, and 12. A follow-up phone call will be conducted at week 4.
Description
Volunteers expressing interest in the study will undergo an initial eligibility assessment, either via telephone interview or by completing an online screening form (Google Form), to verify compliance with the primary inclusion criteria. Candidates meeting these criteria will be invited to attend an information and screening visit, during which the study procedures will be explained in detail and any questions addressed. Individuals who agree to participate will provide written informed consent and will be randomly allocated to one of the four intervention groups. All necessary study materials will be provided at this stage.
Participants will attend three scheduled clinical investigation visits: baseline (day 0), mid-intervention (week 8), and post-intervention (week 12). At each visit, anthropometric and body composition measurements will be performed, and blood pressure will be recorded. Biological samples, including blood, urine, and stool, will be collected. In addition, data regarding dietary intake, physical activity levels, sleep patterns, and gastrointestinal symptoms will be obtained through validated questionnaires.
Eligibility
Inclusion Criteria:
- Volunteers of both sexes between the ages of 18 and 65 years old.
- Volunteers with grade II overweight or obesity (BMI: 27.0-39.9 kg/m2).
- Physical examination and vital signs are normal or clinically irrelevant to the study.
- Volunteers receiving pharmacological treatment may be included if the dosage has remained stable for at least three months prior to study initiation.
- Individuals undergoing treatment for diabetes will be excluded.
- Participants must be capable of understanding the study requirements, willing to provide written informed consent, and able to comply with all study procedures and timelines.
- Body weight must have remained stable (±5%) during the three months preceding study initiation.
Exclusion Criteria:
- Presence of significant functional or structural abnormalities of the digestive system, including but not limited to congenital malformations, angiodysplasia, active peptic ulcer disease, chronic inflammatory or malabsorption disorders, hiatal hernia, or chronic gastroesophageal reflux.
- High alcohol consumption, defined as >14 units per week for women and >20 units per week for men.
- Pregnancy or lactation at the time of screening.
- History of surgical procedures resulting in permanent alterations of the digestive system (e.g., gastroduodenostomy) or joint replacement surgery (hip or knee).
- Diagnosis of arthritis.
- History of any liver disease, with the exception of non-alcoholic fatty liver disease.
- Diagnosis of any type of cancer, current cancer treatment, or history of cancer treatment within the past five years.
- Known allergy or hypersensitivity to any component of the investigational product or to any food that could interfere with study participation and follow-up.
- Presence of cognitive and/or psychological impairment that could affect study compliance.
- Anticipated poor adherence or, in the opinion of the investigator, inability to comply with study procedures.
- Engagement in night-shift work.
- Current use of dietary supplements that may interfere with study outcomes (e.g., nutraceuticals containing compounds with potential weight loss effects).
- Ongoing treatment for weight loss or diabetes.