The question ‘ How many people are obese' is a global question and is not a question for United States of America only. Survey results from 2008 estimate that 2/3 of adults and 25 million children in USA are either overweight or obese. The trend is going higher; the female overweight/obese trend is found to be flat.  Statistic indicates that the obesity health problem in USA and in the world is at epidemic stage. High tech modern world provide easily available nutritious food in many ways. The machine based workplace activity and high tech entertainment gear have taken away the physical activity at work and at home. People eat more nutritious and fast food and do less exercise. This results in more calorie intake and less burning of calories helping a condition to accumulate flat and be overweight/obese. Obesity causes early death, restricted movement, breathing problem, mental instability etc.

            The condition of obesity is determined by body mass index (BMI) of an individual. The BMI is calculated dividing the weight by square of the height. The relation between BMI and obesity is shown below:

            .  BMI                                 Condition

                 < 18.5                            Underweight

            18.5 – 24.99                        Normal

            25.0 – 29.9                          Overweight

            30 – 34.9                             Class I Obese

            35 – 39.9                             Class II Obese

            = > 40                                  Class III Obese

            Further division of Class III Obesity

            > = 35 or 40                          Severe Obesity

            > = 35 or 40 – 44.9 or 49.9   Morbid Obesity

            > = 45 or 50                          Super Obesity

Because of ethnic factors Chine, Japan and some other countries use slightly different BMI index to define obese condition.

Dietary calorie intake and obese has direct relationship. The more calorie intake without burning the extra calories beyond normal causes obesity. Here is the food and drink consumption statistic figure of USA during late 20^th century.

              Year                            USA calorie intake person

               1996                            3654

               2003                            3754

During 1871 – 2000 the obesity index in USA has increased from 14.5 t0 30.9 %.

            Research on obesity has listed other reasons of obesity excluding high calorie intake and less physical activities/exercise:

            . Not enough sleep

            . Environmental pollutants

            . Decreased variability in ambient temperature

            . Decreased rate of smoking

            . Increased use of medication

            . Proportional increase of ethnic and age groups

            . Pregnancy at a later age          

            . Epigenetic risk factor

            . Natural selection for high BMI

            . Assortative mating

There are therapies, medication and surgery procedure to reduce BMI and obesity. The answer to the question ‘How many people are Obese' is many and “Obese” is in epidemic stage in USA.