title: Preservation of fat-free mass after two distinct weight loss diets with and without progressive resistance exercise.
abstract: BACKGROUND
  Preserving fat-free mass (FFM) during weight loss is important in older adults. The purpose was to examine a low-fat diet (LFD) versus a carbohydrate-restricted diet (CRD) with and without progressive resistance exercise (PRE) on preservation of FFM in older men with metabolic syndrome.
  
  
  METHODS
  A total of 42 men (59±7 years) were matched [body mass index (BMI)] and randomized to LFD, LFD&PRE, CRD, and CRD&PRE. PRE groups performed supervised strength training three times per week. Body weight, composition, metabolic syndrome criteria, and strength were measured at baseline and week 12. A 3-day diet record was kept at baseline and at weeks 1, 6, and 12.
  
  
  RESULTS
  Attrition (24%) was similar between groups. Depicted as % carbohydrate:fat:protein, the intervention diet was: LFD=55:24:18, LFD&PRE=57:20:20, CRD=16:54:28, and CRD&PRE=12:56:31. Weight (lb) decreased similarly in all groups (LFD, -18.0±7.4; LFD&PRE, -19.8±12.8; CRD, -20.2±8.0; CRD&PRE, -22.7±6.0; P<0.001), and number of participants with metabolic syndrome decreased in all groups (-3, -6, -3, -4, respectively). Percent of weight loss from appendicular FFM was 27.5%, 15.9%, 15.7%, and 17.3% respectively. A trend was found when comparing LFD and LFD&PRE (P=0.068), and when comparing LFD&CRD (P=0.072). Triglycerides improved more for the LFD&PRE, CRD, and CRD&PRE groups compared to the LFD group (P<0.05). Improvements in high-density lipoprotein-cholesterol were better in the CRD&PRE group (4.1±5.1 mg/dL) versus the LFD group (-5.0±5.9 mg/dL; P<0.01).
  
  
  CONCLUSIONS
  LFD&PRE, CRD, and CRD&PRE preserve FFM similarly. PRE is an important component of a LFD during weight loss in this population.
authors.affiliation: Department of Exercise Science & Sport Studies, Springfield College, Springfield, MA 01109, USA. rwood@spfldcol.edu
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wood
authors.forename: Sara M
authors.initials: SM
authors.lastname: Gregory
authors.forename: Jason
authors.initials: J
authors.lastname: Sawyer
authors.forename: Charles M
authors.initials: CM
authors.lastname: Milch
authors.forename: Tracey D
authors.initials: TD
authors.lastname: Matthews
authors.forename: Samuel A E
authors.initials: SA
authors.lastname: Headley
mesh_terms: D050154:Adiposity; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D001823:Body Composition; D015992:Body Mass Index; D003131:Combined Modality Therapy; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D005163:Factor Analysis, Statistical; D006801:Humans; D008297:Male; D008404:Massachusetts; D024821:Metabolic Syndrome / Q000175:diagnosis / Q000178:diet therapy / Q000503:physiopathology / Q000628:therapy*; D008875:Middle Aged; D053580:Muscle Strength; D050177:Overweight / Q000175:diagnosis / Q000178:diet therapy / Q000503:physiopathology / Q000628:therapy*; D055070:Resistance Training; D013997:Time Factors; D016896:Treatment Outcome; D055105:Waist Circumference; D015431:Weight Loss
chemical_list: D015415:Biomarkers