Australian researchers say that daily doses of fish oil containing Omega-3 fatty acids, when combined with moderate exercise, helped obese people burn off excess weight.

The researchers at the University of South Australia say that the Omega-3 found in fish oil increases the body's fat-burning ability by improving the flow of blood to muscles during exercise.

Researcher Alison Hill says it was a surprise to find that those who took the fish oil doses and exercised lost an average of 2 kg (4.5 lb.) over the three months, especially since they were still eating whatever they wanted.

Sixty eight overweight and obese people were monitored over a three months period; they were divided into four groups; one group took small daily doses of fish oil and another was given sunflower oil with no other alteration to their normal diet.

Both groups undertook moderate exercise programs of a 45-minute walk or run three times a week while another two groups received either fish oil or sunflower oil but did no exercise.

The groups that took sunflower oil, which does not contain Omega-3 fatty acids, and exercised did not lose any weight.

The two groups that did not exercise also lost no weight, the study found.

Meanwhile South African researchers say that primary school children who were given daily doses of fish oil rich in Omega-3, as part of a study, showed improved learning and memory.

Previous research has shown that fish oil, rich in Omega-3 and special polyunsaturated fatty acids, is believed to play a role in the brain development and function of the foetus and young child.

In this recent study scientist Dr. Marius Smuts, from the Nutritional Intervention Research Centre in South Africa, tracked the development of 355 children aged between six and nine.

Half of the children were given two slices of bread covered with 25 grams of spread enriched with fish oil but flavoured with either chicken, curry or tomato sauce.

Dr. Smuts says the children were able to retain information better and were less inclined to take sick days.

The study demonstrated that an Omega-3 fatty acid rich spread not only improved verbal learning, memory and spelling ability among the experimental subjects, but also lessened the number of days the children were absent from school through illness.

Another study in Thailand has also reported Omega-3 supplements taken by primary school students in Thailand reduced the severity and duration of common illnesses.

A six-year study last year by the Rush University Medical Center in Chicago found that Omega-3 fatty acids helped boost brain functioning as well as cut the risk of stroke and also helped protect the brain as people age.

Experts say people should consume at least 400mg of Omega-3 in their food each day, but most don't even get half of this and 20 per cent of the population eat no fish at all.

The research was presented at the Congress of the International Society for the Study of Fatty Acids and Lipids in Cairns, Australia.