Children need a healthy,     1    (balance) diet that gives them enough energy to grow and develop. This means that it's necessary for them    2    (take) in more energy than they use and this extra energy forms new tissues as they grow. However, if children regularly take in too much energy, this is stored as fat and they will put    3    weight.

Childhood obesity is one of the most serious public health    4    (challenge) of the 21st century. The problem is global and is    5    (steady) affecting many low-income and middle-income countries, particularly in urban settings. The trend has increased at an    6    (alarm) rate. Globally, the number of overweight children under the age of five    7    (be)estimated to be over 42 million. Close to 35 million of these are living in developing countries.

The causes of obesity are complex and include genetic, biological, behavioral and cultural factors. Obesity occurs when a person eats    8    (many) calories than the body burns up. If one parent is obese, there is a 50 percent chance    9     　their children will also be obese. However, when both parents are obese, their children have    10    80 percent chance of being obese. Less than 1 percent of all obesity is caused by physical problems.