There is some evidence that dietary supplementation with fish oil has health benefits, especially in respect of some of the known risk factors for cardiovascular (heart) disease such as cardiac arrhythmia. However, supplies of fish oil are limited, and it is desirable to validate alternative sustainable sources of the important omega−3 fatty acid components. It has been suggested that oil from krill, which are small marine crustaceans, may be as effective or possibly more beneficial than fish oil, and may provide a more effective and beneficial supplement. Dietary management of cardiovascular health parameters (such as blood lipids)is becoming more and more important as the rising trends in obesity nationally and worldwide are leading to escalating incidence of diabetes and heart disease. The investigators propose to use some specific novel lipid measurements of cardiovascular risk to test this possibility in a group of men who, although generally healthy, show some risk factors in terms of their weight and metabolic profile.This pilot study will provide preliminary data to show whether krill oil has similar or different effects from fish oil on the cardiovascular health of overweight but otherwise healthy men, and in particular will provide detailed information on alterations in novel lipid markers of cardiovascular disease, which may be a better diagnostic tool than classical lipid measurements (e.g. serum cholesterol). The investigators have been developing and validating new techniques to measure emerging lipid markers of cardiovascular risk accurately and will continue to develop and investigate these techniques during the course of this project. The investigators hypothesise that krill oil will be more efficacious in reducing markers of risk relating to cardiovascular disease.