Aim of the study is to investigate the impact of glycemic index (provided as soft drinks) on changes in insulin sensitivity, metabolic flexibility, and arterial stiffness in response to detraining.

The investigators hypothesize that low glycemic soft drinks decrease the detraining-induced impairment of insulin sensitivity, metabolic flexibility and arterial stiffness.

The duration of the study is 7 weeks: two x 2 weeks intervention (phase A and phase B) with 3 weeks washout phase inbetween. Each 2-week intervention phase consists of an active week followed by an inactive week.

in phase A subjects consume high GI (maltodextrin and sucrose) soft drinks during the inactive week. In phase B subjects consume a low GI soft drink (palatinose) during the inactive week.

subjects were randomly assigned to either start with phase A or with phase B (cross over design).

During the whole study duration all food is provided (55% CHO, 30% fat, 15% protein)

Physical activity will be assessed by a step counter (active phase 7000-10000 steps/d and inactive phase 3000-4000 steps/d).

Inclusion Criteria:

• normal weight men,
• age 18-35 y,
• active life style,
• > 300 min sports/week

Exclusion Criteria:

• food allergies,
• regular use of medication,
• smoking,
• chronic disease,
• vegan/vegetarian diet