title: Energy-restricted, high-protein diets more effectively impact cardiometabolic profile in overweight and obese women than lower-protein diets.
abstract: High-protein energy-restricted diets have demonstrated efficacy in promoting weight loss in overweight and obesity. However, the protein percentage that achieves optimal efficacy and acceptability remains unknown. We sought to assess the effects of three energy-reduced diets with different percentages of calories from protein (20%, 27%, and 35%) on weight loss and lipids. Secondary outcomes included diet acceptability and compliance.
  
  
  
  Six-month, randomized study included women aged 18-80 years with BMI of 27.5-45 kg/m2and who were not taking lipid-lowering drugs. We randomly assigned 91 women to one of three calorie-reduced diets with: protein, 20%, 27%, or 35% (80% from animal protein); carbohydrates, 50%, 43%, or 35%; fat, 30%. Dietary intervention involved individual visits with a nutritionist every 2 weeks during the first 3 months. We performed a follow-up visit at 6 months.
  
  
  
  Eighty women aged 44.0 ± 9.08 years with BMI of 37.7 ± 3.39 kg/m2completed the study. At 3 months, weight loss was -8.16 ± 4.18 kg, -9.66 ± 5.28 kg, and -10.7 ± 4.28 kg in the 20%, 27%, and 35%-protein groups, respectively (P = 0.16). These figures slightly and homogeneously increased at 6 months. Around 65% of women following 35%-protein diet lost ≥10% of body weight vs. ∼33% in 20%-protein group (P = 0.023). Significant decreases occurred in fat mass, lipids and insulin resistance, especially in the 35%-protein group (P < 0.05 vs. 20% protein). This improvement was not fully explained by weight loss. Triglyceride change was negatively correlated with animal-protein intake. All groups provided similar responses to an acceptance, palatability, and satisfaction questionnaire.
  
  
  
  An energy-restricted diet with 35% protein, mostly of animal origin, more effectively impacts cardiometabolic profile than an energy-restricted diet with lower protein content although no clear benefit between diets in terms of overall weight loss was observed. The high-protein diet displayed an excellent safety profile and acceptability. This trial was registered in ClinicalTrials.gov as NCT02160496.
  
  
  
  The clinical trial has been registered in ClinicalTrials.gov (Identifier: NCT02160496).
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain. Electronic address: rmateo.iacs@aragon.es.
authors.forename: Rocío
authors.initials: R
authors.lastname: Mateo-Gallego
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Marco-Benedí
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Sofía
authors.initials: S
authors.lastname: Perez-Calahorra
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Bea
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Baila-Rueda
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Itziar
authors.initials: I
authors.lastname: Lamiquiz-Moneo
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: de Castro-Orós
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Cenarro
authors.affiliation: Unidad Clínica y de Investigación en Lípidos y Aterosclerosis, Hospital Universitario Miguel Servet, Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Civeira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D031204:Caloric Restriction; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D002784:Cholesterol / Q000097:blood; D000073600:Diet, High-Protein; D018753:Diet, Protein-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D023381:Endpoint Determination; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D024821:Metabolic Syndrome / Q000517:prevention & control*; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D050177:Overweight / Q000178:diet therapy*; D016037:Single-Blind Method; D014280:Triglycerides / Q000097:blood; D015431:Weight Loss; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002784:Cholesterol; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D006442:Glycated Hemoglobin; D014280:Triglycerides
keywords: Diets; Energy restriction; Lipids; Protein; Weight loss