Project name: Homo sapiens

Description: Background: Diet induced weight reduction promotes a decrease in resting energy expenditure that could partly explain the difficulty to maintain reduced body mass. Whether this reduction remains after stabilized weight loss is still controversial. The molecular mechanisms are unknown.Objective: To investigate the effect of a stabilized 10%-weight loss on resting metabolic rate, body composition and skeletal muscle gene expression profile in obese women.Design: Obese women were successively submitted to a 4-w very low-calorie diet, a 3-6-wk low-calorie diet, and a 4-wk weight maintenance program to achieve a 10% weight loss. Resting energy expenditure, body composition, plasma parameters and skeletal muscle transcriptome were compared before weight loss and during stabilized weight reduction.Results: Energy restriction caused an 11% weight loss. Stabilization to the new weight was accompanied by an 11% decrease of the resting metabolic rate normalized to the body cellular mass which was below that of lean subjects. The range of the changes in the skeletal muscle transcriptome was modest. The main regulated genes were that of slow/oxidative fiber markers which were overexpressed and the gene encoding the glucose metabolism inhibitor PDK4 which was down-regulated. The knowledge based approach, gene set enrichment analysis, identified pathways related to insulin and interleukin 6 and long term calorie restriction adaptations during weight loss.Set of arrays that are part of repeated experimentsKeywords: Biological ReplicateOverall design: Overall design: Subjects and study design: Six obese Caucasian premenopausal women were submitted to a weight loss program: including three phases. The first one was a 4-wk very low calorie liquid formula diet (3.3 MJ/day). The second phase was a 3 to 6-wk low calorie diet (4 to 5 MJ/day) until reaching a loss of 10% of the initial body weight. The last phase was a 4-wk isocaloric diet (mean 5.8 MJ/day), planned to stabilize the new body weight. Percutaneous biopsy of the vastus lateralis muscle was obtained in obese women before and after the weight loss program.Biological ReplicateComplex

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Medical

Release date: 2008-03-26

Last updated: 2007-12-17