What are omega-3 fatty acids?
Not all fat deserves a bad reputation. In fact, some types of fat are vital for your health and wellbeing.
Omega-3 is an essential fatty acid, meaning it must be obtained from food because the body can't manufacture it.
The richest dietary source of omega-3 fat comes from cold water fish such as salmon, mackerel and sardines, but it can be found to a lesser extent in all fish and seafood.
Omega-3 fatty acids are an important building block of every cell in the human body, and are especially important for heart health, reproduction, cognitive function and circulation.
How do omega-3 fatty acids affect weight?
When prepared in a healthy manner, fish and seafood is a lean source of protein and can be a tasty, low kilojoule addition to any weight loss eating plan.
There is also a growing body of evidence to suggest that the omega-3 fatty acids in fish and seafood may help to boost weight loss, or more specifically fat loss.
One recent study reported in the British Journal of Nutrition found that increased blood levels of omega-3 fatty acids were associated with a lower incidence of obesity.
The researchers found that overweight and obese people had blood levels of omega-3 fatty acids almost 1 per cent lower than people with a healthy weight. Increased omega-3 levels were associated with a healthier BMI, a smaller waist, and a lower hip size.
Additional research found that including fish or fish oil supplements as part of a low kilojoule diet resulted in 1 kilogram more weight loss after 4 weeks than a similar diet without seafood or omega-3 supplements.
In other words, the omega-3 fatty acids in fish and seafood have unique, weight reducing properties, and not just because it's a low kilojoule food. The researchers believe that omega-3 fatty acids may aid weight management by increasing the feeling of fullness after a meal (reducing hunger hormones) and by boosting heat production (boosting your metabolism).
The omega-3 fat content of fish and seafood
||Omega 3 content (mg)
|Fsh oil capsule (average)
|Blue eyed cod
What if you don't eat fish and seafood?
Because some people don't eat fish or seafood, or don't eat enough to obtain sufficient amounts of essential fats from their diet, omega-3 fats are now being added to other foods in an effort to boost consumption.
For example, omega-3 enriched eggs, yoghurts and breads are available in most supermarkets. Supplements that provide a concentrated source of omage-3 fatty acids are also widely available.
Micallef, M et al. Br J Nutr. 2009. Published online ahead of print
Am J Clin Nutr. 2007 86: 1267-1274.
Other references available on request