Introduction. An important way of preventing type 2diabetes is by adopting a proper diet by which means appropriate control over blood glycaemia and lipids can be achieved. Objectives. To assess selected biochemical and haematological markers in overweight subjects or those suffering from type 2 diabetes in relation to their estimated dietary intake. Material and methods. The study was conducted in 2012 on n=86 overweight or obese subjects living in Warsaw or its environs, of whom n=43 had type 2 diabetes. Dietary intakes were compared between non-diabetics (control group) and diabetics (test group) by 3 day records, whilst the relevant blood biochemistry and haematology results were obtained from medical records; with patient consent. Results. Diabetic subjects had significantly higher... serum glucose and CRP levels than controls, respectively; 190 vs 98 mg/ dl and 1.4 vs 1.1 mg/dl. Lipid profiles were however more significantly abnormal in controls, compared to diabetics with respectively; total cholesterol 220 vs 194 mg/dl, LDL-cholesterol 131 vs 107 mg/dl and triglycerides 206 vs 157 mg/dl. There were no significant differences in HDL-cholesterol; respectively 55 vs 51 mg/dl. In the diabetics, calorific intakes from carbohydrates, especially sugars, were significantly lower than controls i.e. 9% vs 13%. The proportional share of calories derived from dietary fats did not differ between groups, nevertheless a positive correlation was observed between dietary fat content with blood cholesterol concentrations in diabetics. Conclusions. Disorders of carbohydrate metabolism were confirmed in both overweight and diabetic (type 2) subjects. In addition, both groups demonstrated untoward lipid profiles that correlated with their improper nutrition.