Adding a piece of fruit or a glass of milk to a teenager's breakfast may help protect them from depression, anxiety and disobedience, Australian research suggests.

A study of more than 800 students has found that a complex breakfast is directly linked to better mental health irrespective of family income, the student's weight or exercise routine.

Students who ate from more food groups for their morning meal scored higher on a child behaviour checklist, with an improvement in mood seen for every extra food type added.

"It didn't matter what they added, just that they added something different like a banana to their cereal to make that meal more complete with vitamins and minerals," said lead researcher Therese O'Sullivan, from the Telethon Institute for Child Health Research in Perth.

"From what we found, that makes a huge difference."

The team enlisted 14-year-old girls and boys and analysed their breakfast intake over three days.

They found that just one in four teens ate a high quality breakfast containing three or more of the five food groups, cereals, fruit, vegetables, dairy products, and meats and alternatives like beans, nuts and eggs.

"The overwhelming number just ate from two groups, and too many have just one or none at all, so there is much room for improvement," Ms O'Sullivan said.

The results were compared the students' behavioural scores in a complex questionnaire completed by their parents.

"For every additional food group added the mental health status improved markedly across the sample, and this was regardless of the family income, socio-economic status, the child's exercise (routine), weight and the rest of their diet."

She said this may be because mental functioning is affected by the absorption of a variety of nutrients.

Cereal and milk in particular supply calcium, iron and B vitamins that assist neurotransmitters, chemicals needed to transfer information in the nervous systems that are directly responsible for behaviour and mood.

Breakfast has long been thought vital but research has proven it is most important pre-adulthood as young people are not able to store nutrients as effectively.

"The liver stores nutrients, but kids have a much smaller liver, so until they become fully grown they can't store nutrients as effectively," the dietician said.

"For that reason breakfast is the most important way for them to get vitamins and minerals for brain function needed after the overnight fast."

The research will be presented at the national dieticians conference on the Gold Coast this week.

澳大利亞研究機構建議，給少年兒童的早餐加一塊水果或者一杯牛奶有助于他們消除抑郁，緊張和違抗情緒。

對800多名學生的研究已經表明，復合早餐直接關系更好的心理健康，不必考慮家庭經濟收入，學生體重和鍛練常規。

吃更多食物品種早餐學生在兒童行為檢查表上分數高一些，發現每添加一種食物就有心情改善。

“添加什么食物不重要，只要添加各種不同的食品，例如，把香蕉加到飯食中使得這一餐維他命和礦物質更完美，”珀斯, 佩思(澳大利亞城市)電視臺兒童健康研究所的賽澳斯.奧莎麗娃主任這樣說。

從我們的發現中看出，上述方法帶來巨大變化。

研究組針對14歲的男孩和女孩，連續3天分析他們用的早餐。

研究人員發現只有四分之一的兒童吃高品質的含3種或者超過5種食物的早餐，這5種食物是谷物類，水果，蔬菜，奶制品和肉類，而豆，花生和雞蛋為可替換食品。

奧莎麗娃說，“絕大部分兒童只吃2種類食物的早餐，更有許多只吃一種食物的早餐甚至不吃早餐。因此，大有改善空間。”

研究結果選來自一張由家長完成的學生行為特征詳細調查表，對表上的記分進行分析比較得出結果。

每次添加食物各類，抽樣試驗兒童的心理健康狀況明顯改善。這個研究不顧及家庭經濟收入，兒童鍛練常規，體重和其它飲食。

她說，“這種改善可能是因為體內吸收了多種營養對心理機能起了作用。”

谷物和牛奶特別提供鈣，鐵和維他命B，其作用是輔助體內神經傳遞介質，它是一種化學物，在神經系統中傳遞信息所必需的物質，直接負責行為和情緒。

早餐一直被認為是必不可少的，而研究證明早餐對兒童來說極其重要，因為在成年以前，年輕人還不能夠很有效地儲藏營養。

營養學專家說，“肝臟儲藏營養，但是兒童的肝臟非常細小，所以要到他們長大以后才能有效地儲存營養。”

“正是這個原因，早餐是他們獲取維他命和礦物質供應大腦之最重要途徑，在一個長夜停食后大腦需要補充營養。”

本研究成果將在本周黃金海岸國民營養學專家會議上公布