title: Energy density and weight change in a long-term weight-loss trial.
abstract: BACKGROUND
  Health risks linked to obesity and the difficulty most have in achieving weight loss underscore the importance of identifying dietary factors that contribute to successful weight loss.
  
  
  METHODS
  This study examined the association between change in dietary energy density and weight loss over time. Subjects were 213 men and women with BMI of 30-39 kg/m2 and without chronic illness enrolled in 2004 in a randomized trial evaluating behavioral treatments for long-term weight loss. Subjects completed a 62-item food frequency questionnaire at baseline and at 6, 12, and 18 months.
  
  
  RESULTS
  Pearson correlations between BMI and energy density (kcals/g of solid food) at baseline were not significantly different from zero (r = -0.02, p = 0.84). In a longitudinal analysis, change in energy density was strongly related to change in BMI. The estimated beta for change in BMI (kg/m2) of those in the quartile representing greatest decrease in energy density at 18 months compared to those in the quartile with the least was -1.95 (p = 0.006). The association was especially strong in the first six months (estimated beta = -1.43), the period with greatest weight loss (mean change in BMI = -2.50 kg/m2 from 0-6 months vs. 0.23 kg/m2 from 12-18 months) and the greatest contrast with respect to change in energy density.
  
  
  CONCLUSIONS
  Decreased energy density predicted weight loss in this 18 month weight loss study. These findings may have important implications for individual dietary advice and public health policies targeting weight control in the general population.
authors.affiliation: University of Minnesota, Minneapolis, MN, USA. flood009@umn.edu.
authors.forename: Andrew
authors.initials: A
authors.lastname: Flood
authors.forename: Nathan
authors.initials: N
authors.lastname: Mitchell
authors.forename: Melanie
authors.initials: M
authors.lastname: Jaeb
authors.forename: Emily A
authors.initials: EA
authors.lastname: Finch
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Laqua
authors.forename: Ericka M
authors.initials: EM
authors.lastname: Welsh
authors.forename: Annie
authors.initials: A
authors.lastname: Hotop
authors.forename: Shelby L
authors.initials: SL
authors.lastname: Langer
authors.forename: Rona L
authors.initials: RL
authors.lastname: Levy
authors.forename: Robert W
authors.initials: RW
authors.lastname: Jeffery
references.citation: Am J Clin Nutr. 1999 Oct;70(4):448-55
references.pmid: 10500012
references.citation: Am J Clin Nutr. 2003 Oct;78(4):684-9
references.pmid: 14522725
references.citation: Control Clin Trials. 2002 Apr;23(2):157-71
references.pmid: 11943442
references.citation: Am J Clin Nutr. 1998 Mar;67(3):412-20
references.pmid: 9497184
references.citation: Obesity (Silver Spring). 2006 Oct;14(10):1795-801
references.pmid: 17062810
references.citation: Epidemiology. 1990 Jan;1(1):58-64
references.pmid: 2081241
references.citation: JAMA. 2006 Apr 5;295(13):1549-55
references.pmid: 16595758
references.citation: Am J Epidemiol. 1986 Sep;124(3):453-69
references.pmid: 3740045
references.citation: Int J Obes Relat Metab Disord. 2000 Apr;24(4):395-403
references.pmid: 10805494
references.citation: J Nutr. 2005 Feb;135(2):273-8
references.pmid: 15671225
references.citation: Eur J Clin Nutr. 2001 May;55(5):349-59
references.pmid: 11378808
references.citation: Nutr Rev. 2004 Nov;62(11):403-13
references.pmid: 15622713
references.citation: Obes Res. 1994 Jul;2(4):307-13
references.pmid: 16358394
references.citation: Nutrition. 2007 Nov-Dec;23(11-12):798-806
references.pmid: 17936194
references.citation: Cancer Epidemiol Biomarkers Prev. 2005 Dec;14(12):2826-8
references.pmid: 16364996
references.citation: N Engl J Med. 2003 Apr 24;348(17):1625-38
references.pmid: 12711737
references.citation: World Health Organ Tech Rep Ser. 2000;894:i-xii, 1-253
references.pmid: 11234459
references.citation: Am J Epidemiol. 1978 Sep;108(3):161-75
references.pmid: 707484
references.citation: Am J Clin Nutr. 1999 May;69(5):863-71
references.pmid: 10232624
references.citation: Int J Obes (Lond). 2005 Aug;29(8):950-6
references.pmid: 15917854
references.citation: Am J Clin Nutr. 2007 Jun;85(6):1465-77
references.pmid: 17556681
references.citation: Am J Clin Nutr. 1997 Feb;65(2):409-18
references.pmid: 9022524
references.citation: JAMA. 2003 Jan 1;289(1):76-9
references.pmid: 12503980
references.citation: JAMA. 2002 Oct 9;288(14):1723-7
references.pmid: 12365955
references.citation: Am J Clin Nutr. 2007 May;85(5):1212-21
references.pmid: 17490955
references.citation: Am J Clin Nutr. 2001 Jun;73(6):1010-8
references.pmid: 11382653
references.citation: Obes Res. 2005 Jun;13(6):1052-60
references.pmid: 15976148
references.citation: Am J Clin Nutr. 2006 Jun;83(6):1362-8
references.pmid: 16762948
references.citation: Diabetes Care. 2007 Jun;30(6):1374-83
references.pmid: 17363746