Impact of Overfeeding and Following Exercise Training in Individuals With and Without Increased Risk of Type 2 Diabetes

All participant's individual energy requirement will be determined in mega joules (MJ) per day. The energy requirement will be multiplied by a factor 1.5 for a low physical activity level (PAL). The MJ will be rounded up or down to the nearest whole number. The participant will receive food corresponding to \ 25% additional energy above their calculated energy requirement. The 25% extra energy will be supplied to the participants for 4 weeks in the form of food containing simple carbohydrates. The subjects will be given a daily snack package containing processed foods or refined foods such as sweets, cookies, soft drinks, juice etc. To ensure an adequate energy surplus (i.e. weight gain), physical activity has to be decreased to a low level during the 4 weeks overfeeding period.

Half of the participants will be randomized to a 3-month exercise-training program. The training program consists of combined aerobic training and strength training. The training program is performed unsupervised 3 times per week 45 minutes per session for 3 months in the local fitness center. Before engaging in the training program a maximal oxygen consumption test (VO2 max) are conducted and the maximal heartrate (HR) are determined.Participants are wearing the Polar V800 HR monitor and are asked to note their HR in a training log at the end of the last interval at each training session. The strength training program consist of 6 exercises (2 exercises paired together) involving the large muscle groups. The first training session is completed supervised at Rigshospitalet . After 6 weeks the training program is adjusted. Compliance will be ensured by phone calls, text messages and e-mails from study personnel.

The other half of the participants will be randomized to a 3-month with normal physical activity level (control). The participants will have to return to the physical activity level they had before entering the study (baseline level). Compliance will be ensured by phone calls and text messages from study personnel. The subjects will wear a simple pedometer on the hip showing the number of steps. Once a week a text message (SMS-track) is automatically sent asking the participants to enter the weekly number of steps. The test personnel receive the reply and contact the participant if the number of steps does not match the baseline level. During the first and the last 7 days of the exercise intervention participants are wearing 2 accelerometers measuring their physical activity behavior.