Study: NCT00139477

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Metformin
Description: Metformin, 250mg by mouth twice a day with meals will be started and if tolerated increased to 500mg twice a day in 3 days in those less than 12 years old and titrated further to 1000mg twice a day if tolerated.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Metformin
Description: Metformin, 250mg by mouth twice a day with meals will be started and if tolerated increased to 500mg twice a day in 3 days in those less than 12 years old and titrated further to 1000mg twice a day if tolerated.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Dietary modification with caloric restriction
Description: The life style intervention changes will include a hypocaloric diet representing at least a 500 kcal/day reduction based on their dietary histories and Resting Energy Expenditure (REE) determined by the initial calorimetry.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Dietary modification with caloric restriction
Description: The life style intervention changes will include a hypocaloric diet representing at least a 500 kcal/day reduction based on their dietary histories and Resting Energy Expenditure (REE) determined by the initial calorimetry.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Establishment of exercise protocol
Description: Participants will attend the Fitness Center 3 times per week and supervised by an exercise technician or exercise specialist. Exercise will be individually prescribed for each participant based on their functional abilities. Exercise will consist of 5-10 minutes for warm up and stretching, followed by 15-30 minutes of cardiovascular exercise (i.e. treadmill, bicycle ergometer, rower, nustep, etc), 10-20 minutes of strength training (supervised using weight stack equipment), and 5-10 minutes of cool down and stretching. As children typically do not need an exercise prescription based on heart rate, we will familiarize them with perceived exertion scales and monitor that they are exercising in the moderate to hard range of perception of effort. Participants will be started at 15 minutes of cardiovascular exercise and 10 minutes of strength training exercise, progressing by 2-3 minutes every week until 30 and 20 minutes is achieved for each respectively.

Intervention type: BEHAVIORAL
Group type: ACTIVE_COMPARATOR
Intervention: Establishment of exercise protocol
Description: Participants will attend the Fitness Center 3 times per week and supervised by an exercise technician or exercise specialist. Exercise will be individually prescribed for each participant based on their functional abilities. Exercise will consist of 5-10 minutes for warm up and stretching, followed by 15-30 minutes of cardiovascular exercise (i.e. treadmill, bicycle ergometer, rower, nustep, etc), 10-20 minutes of strength training (supervised using weight stack equipment), and 5-10 minutes of cool down and stretching. As children typically do not need an exercise prescription based on heart rate, we will familiarize them with perceived exertion scales and monitor that they are exercising in the moderate to hard range of perception of effort. Participants will be started at 15 minutes of cardiovascular exercise and 10 minutes of strength training exercise, progressing by 2-3 minutes every week until 30 and 20 minutes is achieved for each respectively.