In order to investigate if individuals, carrying genetic variants predisposing to obesity, respond differently to visual presented food images than non-carriers the investigators aim to screen 500 people for a common risk variant in the FTO gene. From those 500 screened 40 subjects, 20 homozygous for the risk allele and 20 homozygous for a non risk allele will be selected for the second step in the study. This part involves the fMRI technique to visualize the brain response, focus on reward system activation, when food images are visually presented in the scanner. Factors regarding eating behavior, sleep, physical exercise and relation to food are investigated in the first part of the study as well as clinical parameters such as BMI.

Inclusion Criteria:

• No medications (except contraceptives including estrogen)
• No metabolic disorders/diseases
• Right handed
• Color vision
• Normal sleep-wake rhythm (eg. shift workers can not participate)

Exclusion Criteria:

• Specific preferences of food, for example vegetarians
• Grandparents originating from country outside the Nordic area
• Metallic implants