Background: Excess weight (EW) a public health problem in First Nations living on the reserves of British Columbia (BC). EW is a multifactorial condition involving biological, genetic, cultural and environmental and sociodemographic and lifestyle factors. We hypothesize that age is a risk factor of excess weight in that population. The objective of this study was to determine whether age is an important factor to be considered in interventions aiming to prevent or manage excess weight, specifically obesity. Method: A cross-sectional study on data collected in 2008 and 2009 through a research study named “First Nations Food, Nutrition and Environment Study” (FNFNES), aiming to document the nutritional status and exposure to contaminants in Canadian First Nations communities living south of the 60th parallel. Three level’s random sampling: province, communities and households. 493 women and 356 men aged 19 years and over were randomly selected from households in 20 communities. The statistical analysis software (SAS 9.1) was used to carry out univariate, bivariate and multivariate analysis. Results: Association between excess weight and age was observed only in women. As compared to reference age group (19 – 30years), obesity was increased 2.2 times in the 31 to 50 years age category and 4.2 times in the 50 to 70 years category. Similar trend was observed for overweight which augmented 1.06 and 1.28 times respectively in the 31 to 50 years and 51 to 70 years categories. No association was observed in men. Conclusions: EW was associated to age in the FN women. In men, although no significant association was seen between the two variables, the prevalence of EW increased with age in bivariate analysis. Policies aiming reduction of excess weight should be implemented in early life, in childhood, for a healthier and safer adulthood.