A Study to Assess the Effect of Diets With Different Protein Composition - Mainly Coming From Lean Red Meat - in Body Weight and Lipid Profile in Overweight and Obese Women

A Randomized Study to Assess the Effect of Diets With Different Protein Composition - Mainly Coming From Lean Red Meat - in Body Weight and Lipid Profile in Overweight and Obese Women

The objective of the study is to assess the effect of diets with different protein composition (20%, 27% and 35%), mainly coming from animal proteins such as lean red meat, on body weight and lipid profile in overweight and obese women. A dietary intervention is carried out during 3 months in 90 women who are individually randomized to an hypocaloric diet with three types of macronutrient composition: 1) 35% proteins, 30% fat and 35% carbohydrates; 2) 27% proteins, 30% fat and 43% carbohydrates and 3) 20% proteins, 30% fat and 50% carbohydrates. Around 50% of total proteins in diet come from lean red meat (leg or shoulder of lamb) by providing up to 15 different recipes to participants to use them as part of the diet. At the beginning of the study, after 6 weeks and at the end of the intervention, the following parameters are determined: anthropometric (weight, waist circumference, body mass index and body composition), blood pressure, dietary (72-hours dietary registry) and exercise assessments and biochemical analysis (total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apolipoprotein A1, apolipoprotein B, iron, transferrin, ferritin, uric acid, glucose, HbA1c, insulin and adipokines). In 3-months visit, participants will be advised to follow the prescribed diets during the next 3 months. Monitoring visits with the nutritionist will not be performed. A follow-up visit will be done after 3-months of end of intervention (at 6-months after beginning the study) to assess the long-time efficacy on main endpoint of each diet. In this visit only anthropometric parameters (weight, waist circumference, body mass index and body composition) will be determined.

Inclusion Criteria:

• Age: 18-80 years old.
• Body mass index between 27.5 - 40.
• Steady weight in last 3 months (±3 kg).
• Informed consent provided.

Exclusion Criteria:

• Presence of uncontrolled endocrinological pathology (including hypothyroidism).
• Type 2 diabetes mellitus with bad metabolic control (HbA1c > 8%).
• Lipid-lowering drugs in the last 3 months.
• Intake of functional foods with plant sterols in the past 6 weeks.
• Vitamin supplements intake.
• Hormone replacement therapy.
• Consumption of Orlistat in the last 2 months
• High intake of alcohol (> 30 gr./day).
• Any serious disease which involves less than 1 year life expectancy or, in investigators judgment, limit the follow-up of an homogeneous diet throughout the study.
• Pregnancy or intention of pregnancy during the study.