It is well known that weight losses in the range of 2.55% are able to improve factors of the metabolic syndrome such as insulin sensitivity. Several studies have been published concerning weight loss and subsequent changes in inflammatory markers and indicate that higher weight losses are necessary to affect the inflammatory markers than are needed to affect insulin sensitivity. Some data showed impairment of insulin sensitivity in diabetic patients during starvation. The aim of our study was to investigate the effects of short-term fasting (72 h) on hs-C-reactive protein (CRP) and insulin sensitivity (HOMA-IR) in patients with normal glucose tolerance. Seven patients were included in the study (mean BMI 23.8±2.91 kg/m2; mean age: 37.29±4.40 years). CRP, basal plasma glucose, insulin and C-peptide were measured every 6 h during 3 days. Values measured at 0600 h each day were used for comparison. CRP increased but not significantly from day 0 to 4 (1.89±0.68 vs 1.63±0.71 vs 2.87±1.24 vs 3.47±1.59 mg/l, P>0.05, respectively). HOMA-IR decreased significantly during 72 h of fasting (4.22±0.69 vs 2.12±0.37 vs 1.38±0.27 vs 0.97±0.17, P<0.05 respectively). C-peptide values decreased significantly during fasting (0.86±0.18 vs 0.39±0.07 vs 0.28±0.09 vs 0.17±0.05 nmol/l, P<0.05, respectively). In conclusion, short-term fasting in subjects with normal glucose tolerance increase insulin sensitivity as well as non significantly increase hs-CRP. This could be part of general body adaptation to starvation.