Interactions between genes and environment, are likely to be crucial in the development of the common diseases such as type 2 diabetes. It was recently shown that FADS1 and FADS 2 genotypes are the strongest genes in a genome-wide analysis regulating serum fatty acid profile.The aim of this study is to test if subjects with the CC and TT genotypes of the FADS1 gene (rs174547) respond differentially to a diet supplemented with linoleic acid (substrate for FADS). We hypothesize that subjects with the TT genotype with more active desaturases will be more sensitive to dietary modification leading to more robust differences in serum FA profile, tissue inflammation and serum lipids.

Lean and overweight subjects (BMI >20kg/m2 <29kg/m2 ) with CC and TT genotypes of FADS1 polymorphism (rs174547) were recruited from the METSIM study (METabolic Syndrome in Men, currently >10000 men included from the population living in Kuopio). The potential participants were asked to contact study nurse if willing to participate. Twenty six subjects with CC genotype were selected after matching with thirty six subjects with the TT genotype for age, BMI and medication.

Study diet were isocaloric following the habitual diet of the participants with a supplement of 30-50 ml (25-45 g) sunflower oil daily depending on body weight. Thus, approximately 16-28 g (6 E%) LA daily were provided on top of the average intake of approximately 10-12 g (4.5 E%). This dose of sunflower oil is not known to cause any side effects or adverse events and even higher doses have been safe.

Food records were collected at the beginning (4 days) and during the third week of the study (7 days) to estimate daily intake of macronutrients and specifically of different fatty acids.

Inclusion Criteria:

Participant of Metabolic syndrome in men (METSIM) cohort BMI 20-30 kg/m2 Healthy CC/TT genotype (rs 174547)

Exclusion Criteria:

Type 2 diabetes Other chronic disease