The purpose of this trial is to better define how individuals with different genetic make-ups will require different interventions to improve their methylation potential and nutrient status.

Despite the increasing incidence of overweight and obesity among children, nutritional deficiencies are still a concern.

A low intake of vitamins and minerals is associated with a reduction in the antioxidant capacity. Some vitamins are associated with chronic diseases including overweight and obesity.

S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are the substrate and product of essential reactions; the SAM:SAH ratio has been associated with health and is an indicator of cellular DNA methylation potential.

Low level of this ratio may affect short and long term health. In this explorative knowledge building open interventional study, subject to be enrolled are children or adolescents 9 to 13 years of age per year (n=180 per year, over 2 years). The study consists of 6 weeks nutritional intervention followed by a 6 weeks follow up.

In this study, genomics, proteomics, lipidomics analysis will be performed, in addition to biochemistry, hematology and vitamins analysis.

Inclusion Criteria:

• Children or adolescents 9 to 13 years of age.
• Clinically stable.
• Normal weight, overweight and obese.

Exclusion Criteria:

• Disease diagnosis.
• At least one episode of axillary temperature >37°C over the prior 15 days.
• Three or more episodes of liquid or semi-liquid stools over the prior 24 hours.
• Supplementation with vitamins and/or minerals.
• On a supervised diet for reducing weight or any other type of diet restriction.
• Currently participating or having participated in another clinical study during the last 4 weeks prior to the beginning of this study.