What is Obesity? Overweight and obesity are caused by an energy imbalance. Everyone needs to get a specific amount of energy from their food and drink in order to keep the body running. We measure this energy in calories. Our weight will usually stay the same if we eat the same number of calories as we burn.
If we eat and drink more calories than we get rid of, our body will store the extra energy as fat, and we will start to gain weight.
"More than a third of adults (34.9 percent) were obese as of 2011 to 2012. More than two-thirds of adults were overweight or obese (68.6 percent). Approximately 17 percent of children and teenagers (ages 2 to 19) were obese from 2011 to 2012, and 31.8 percent were either overweight or obese."
In order to stay healthy, we need to maintain our energy balance. That means that we need to match the number of calories that we eat to the number of calories that our body uses. So we can either eat less, avoid fattening foods or burn more calories.