Parents always provide nutritional foods for their children, as they think nutritional foods can supplement essential nutrients and keep healthy for children. However, not all the foods can maintain children healthy. Some certain foods can cause the diseases and endanger the health among children. 

Acidic foods can cause autism among children. Acidic foods mainly include meat, eggs and sweetmeats. Many parents regard these foods as nutritional and healthy ones. But the metabolic products of these foods inside the human body are acidic substances and they can make the blood acidic. The excessive intake of acidic foods can cause the acidic physical constitution for children and consume too much potassium, calcium and magnesium to maintain the normal growth and development of the brain so as to cause the disorder of thinking and autism. Therefore, in order to avoid the production of autism, parents should adjust the dietary structure and decrease the intake of high protein, high fat and high sugar for their children. The intake of vegetables and fruits should be increased.

Refined foods can cause near-sightedness. According to the dieticians, the long-term intake of refined foods can decrease the absorption amount of vitamin B so as to affect the normal development of the nerve system. At the same time, the content of chromium inside the body can also be decreased to affect the development of eyesight and cause near-sightedness. Generally speaking, the human body needs 50 to 200 milligrams of chromium every day, while 80% of chromium has been lost in refined foods. Therefore, parents should provide some coarse foods for their children to improve the absorption of chromium.

Coffee can affect the growth of bones of children. Coffee contains caffeine which can hinder the development of the bones. The frequent intake of coffee and other foods containing caffeine can cause the short height. Therefore, parents should let their children drink boiled water or fruit juice frequently and avoid drinking coffee.

Fillet can cause dental fluorosis. Fillet is made of marine fish, containing abundant nutrients like protein, calcium and phosphorus and nice taste. According to the research, the content of fluorine contained in fillet is 2400 times higher than that in beef and mutton and 4800 times higher than that in vegetables and fruits. The chronic fluorosis can seriously affect the development of teeth of children. The spots and stripes can appear on the surface of teeth to cause dental fluorosis. Therefore, children should not eat fillet excessively.

In short, although nutritional foods can supplement essential nutrients for children, the intake of these foods should be in a moderate amount so as to keep children healthy.