The use of zein nanoparticles as vehicles for drug delivery is under study, but of the effects observed in empty nanoparticles, in laboratory animals, the reduction of glucose levels was something worth studying. Thus, the present research on patients with prediabetes has been proposed. The objective is to assess the efficacy of zein nanoparticles on the glycemic control. For this purpose, a randomized, double blind crossover study has been designed.

Target sample size is 60.

Inclusion Criteria:

• Overweight or obesity (BMI between 25 and 40 kg/m2
• Presence of prediabetes (fasting glycemia in blood between 100 and 126 mg/dL)
• No weight variations considered relevant (+/- 5%) in the last 3 months
• Metformin treatment is allowed, as far as dose is stable (at least 2 months with unvaried dose).
• Good physical and psychological state.

Exclusion Criteria:

-

The products (experimental and Placebo), will be produced by an external producer, who will retain the codes. None of the researchers involved in the study development or analyses will know the association until the end of the study.