Omega-3 acids and their properties are the subject of hundreds of pieces of research each year, so nutritional recommendations are constantly changing and being updated.

Some countries and international organisations (such as the World Health Organisation (WHO) and the French Agency for Food Safety (Agence Française de Sécurité Sanitaire des Aliments: AFSSA)) have issued recommendations supporting a daily dose of 2g of omega-3.

 

These recommendations have been criticised by some experts, since they are not high enough to reduce coronary disease in North America.
Remember that in France, the daily consumption of EPA and DHA is between 0.15 and 0.2g.

It cannot really be said that there is a nutritional deficiency of n-3 fatty acids, but the importance of these fatty acids for the prevention of civilisation diseases (cardiovascular diseases, cancer, metabolic syndrome, psychiatric problems...) justify a monitoring of their consumption.  It is now recognised that intake of omega3 fatty acids is insufficient (by half) in relation to the Recommended Daily Allowance for western populations.

It is important to make the distinction between the recommendations for the general population in good health from recommendations for addressing a specific health issue (for example optimum condition of the cardiovascular system) where doses will be higher.
Omega-3 fatty acid intake for the general population is calculated according to total energy intake. Fats are important components of the diet as they provide energy, essential fatty acids and liposoluble vitamins. Intake of lipids should not exceed 30% of energy ingested. A limited consumption of saturated fatty acids is recommended, as they increase the risk of cardiovascular complications. Omega-3 fatty acid intake should represent at least 0.5% of total energy intake. For example, a daily calorie intake of 2000Kcal represents a total dose of around 1g of omega3 per day. Around half can be provided through very long chain omega-3 fatty acids of marine origin, i.e. a quantity of 500mg of EPA and DHA.