Researchers have found a link between severe childhood asthma and fast food. A new study in the medical journal Thorax found that three or more weekly servings of junk food substantially increased the risk among teens and young children. The study says it could be the food's high concentrations of saturated fats which compromise the immune system of children, making them more prone to a whole range of health problems. Al Jazeera's Simon MacGregor Wood reports from London.
