Study aim: To examine the effect of consuming red beetroot powder on metabolic factors in people with pre-diabetes. Design: Clinical trial with a control group and parallel design, double-blind, randomized, phase 3 on 74 patients. The WinPepi software was used for randomization. Settings and conduct: Beetroot has the potential to be effective and therapeutic in people with pre-diabetes. People with pre-diabetes who refer to Isfahan Endocrine and Metabolism Research Center and meet the inclusion criteria will be invited to participate in this research. After obtaining informed consent, people will be asked to refer to the Endocrine and Metabolism Research Center in a fasting state of at least 8 hours during their next visit (first visit), and fasting and two-hour blood glucose samples, as well as blood and urine samples necessary for Biochemical measurements will be collected. Besides, information on anthropometrics, demographics, blood pressure, general characteristics, food intake and physical activity will be collected. At the end of week 12 (second visit), all measurements from the first visit will be repeated. During the study, the participants, the trained questioner, and the outcome examiner will be blinded to the type of intervention. For blinding, the sachets of both intervention and placebo groups will be identical in terms of shape, color, weight and other physical characteristics. Participants/Inclusion and exclusion criteria: Inclusion criteria: people with prediabetes aged 20-80 years old. Non-Inclusion criteria: use of any anti-diabetic agent except metformin; pregnant or lactating women. Intervention groups: Intervention: Red beetroot powder. Placebo: Rice powder Main outcome variables: Main outcomes: 2-hour blood glucose level; fasting blood sugar; fasting insulin; hemoglobin A1C; homeostatic model assessment for insulin resistance; the quantitative insulin-sensitivity check index