I'm not aware of the diseases. However, have you heard how on average, obese people will spend more energy than the normal sized person due to the extra body mass?
yeah and  On average, obese people have a greater energy expenditure than a healthy person
I have a friend who is suffering from obesity, do you know what that is? I do. Obesity is a medical condition in which excess body fat has accumulated. Ohh okay I see, is there anyway to reduce that excess body fat? Not sure on that but when over a certain BMI value, a person is generally considered obese then. BMI is calculated from a person's weight divided by the square of their height. Okay I see, that is interesting to note, I am not sure what her BMI is, but she told me she has been diagnosed with obesity.  Can you tell me more about it? Sure, the chances of a number of diseases and conditions are increased due to obesity. I have heard about that before, what types of diseases and conditions does it increase?
On average, obese people have a greater energy expenditure than their normal counterparts due to the energy required to maintain an increased body mass.