Obesity, Physical Inactivity or Dietary Fat ?

Summary

Obesity is the consequence of a chronic disequilibrium of fat balance. Genetic factors determine predisposition to obesity, but the most often mentioned idea is that environmental factors, such as a high-fat diet and a sedentary lifestyle, join to favour weight gain and explain the increased prevalence of obesity in our westernized societies. Since lipogenesis is negligible in humans, obesity represents the consequence of altered fat partitioning between oxidation and storage, likely due to a preferential directing of dietary fat towards adipose tissue and away from muscle. Interventions that favour partitioning of dietary fat towards muscle for oxidation might thus protect against weight gain. Exercise may be one kind of such intervention but the scant data on dietary fat metabolism does not allow clear conclusions, in particular in obese subjects. One question concerns the impact of the type of fat eaten: the effects of physical inactivity may vary according to the length and saturation degree of the fatty acids. We hypothesize that 1) physical activity of moderate intensity, independently of its effect on energy balance, will favor a preferential trafficking towards adipose tissue, will modify the expression of genes implicated in fat oxidation and storage and partly correct the abnormalities observed in obese subjects, 2) effects of physical activity vary according to the saturation degree of fat. Twelve obese subjects, aged 18 to 55, will undergo tests before and after 2 months of training at current recommendations to ascertain dietary fat partitioning using stable isotopes and to determine changes in gene expression with muscle and adipose tissue microbiopsies.

Conditions

• Obesity

Interventions

BEHAVIORAL

Physical training

Sponsors & Collaborators

• PRNA (INSERM/INRA)

  collaborator UNKNOWN

• Fondation Coeur et Artères

  collaborator OTHER

• Centre National de la Recherche Scientifique, France

  collaborator OTHER

• Louis Pasteur University, Strasbourg

  collaborator OTHER

• University Hospital, Strasbourg, France

  lead OTHER

Principal Investigators

• Chantal Simon, MD · Hôpitaux Universitaires de Strasbourg

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

55 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2007-03-31

Completion

2011-08-31

Countries

• France

Study Locations