The primary objective of STAR01 is to evaluate the performance and safety of the medical device (class IIb) SiPore15™ after a 12-week long treatment in the target population of obese and overweight subjects with prediabetes or newly diagnosed type 2 diabetes. The expected performance and safety of the device is based on the safety and efficacy results seen in an earlier First-in-Man (FIM) study. The safety and tolerability of SiPore15™ is based on the well-established and extensive use of food grade silicon dioxide and favorable data from the FIM study. Data on side-effects will be collected for verification of device safety. The study duration is 24 weeks in total, 12 weeks from baseline on investigational medicinal device (IMD) treatment, with additional 12 weeks off treatment. The study population is planned for forty (40) subjects to be enrolled, male and females, age >18 years and fulfilling all inclusion criteria but none of the exclusion criteria.

Inclusion Criteria:

1. Signed informed consent form.
2. Male or female aged ≥18 years on the day of screening.
3. Female subjects of childbearing potential must be on non-oral contraceptives, postmenopausal or sterile.
4. Prediabetes or newly diagnosed T2D (not on blood sugar lowering drugs) defined as HbA1c levels: ≥42 to ≤57 mmol/mol (≥6.0 to ≤7.5%-according to DCCT).
5. Body mass index (BMI) >25 kg/m2 and > or = 40 kg/m2.
6. Stable weight for 3 months (+/-5 kg).
7. No extreme changes in diet for the last 6 months such as anorexia, bulimia, etc.
8. Subject must be able and willing to attend all scheduled visits and comply with all study procedures with no planned holiday longer than 2 weeks during the 12 weeks of treatment.

Exclusion Criteria:

1. Diagnosed with type1 diabetes/Latent Autoimmune Diabetes in Adult (LADA) or secondary diabetes, as part of medical history or confirmed by laboratory test.
2. Previous or current Metformin treatment or other glucose reducing drug therapy within 3 months before screening visit.
3. Previous or current statin treatment or other blood lipid (LDL) reducing drug therapy, within 12 months before screening visit.
4. Previous or current medication known to cause weight loss or weight gain, such as systemic corticosteroids, thyroid hormones or Estrogen, within 1 month before screening visit.
5. Subjects who stopped smoking within 6 months before screening visit.
6. Diagnosed with chronic somatic diseases, except for obesity and treatment naive T2D, that in the opinion of the investigator may therefore affect metabolic and /or intestinal function (e.g. inflammatory bowel disease, intestinal dysfunction, pancreatic dysfunction, other causes of malabsorption, recent (past 6 months) neoplastic disease.
7. Any history of myocardial infarction or stroke within the 6 months before screening visit.
8. Anemia, donated blood or other major blood loss within 3 months from screening visit that in the opinion of the clinician may interfere with the study.
9. Pregnancy or breast feeding.
10. Allergies to silicon dioxide.
11. A diagnosed state that requires use of vitamin and/or mineral supplements during the study.
12. Previous major gastric surgery that may affect the study outcome, such as bariatric surgery.
13. Ongoing or unstable kidney condition with moderate to great reduction in glomerular filtration rate < 90 ml/min (GFR) that may affect metabolic parameters during the trial.
14. Ongoing or unstable liver condition that may cause changes in liver enzymes exceeding 2x upper normal levels.
15. Psychiatric or cognitive disorder and/or behavioral problems which in the opinion of the clinician may interfere with the study.
16. History of or ongoing alcohol or drug addiction.
17. Participation in any study involving an investigational drug or medical device within the past 30 days before the screening visit.
18. Belongs to a vulnerable population or has any condition such that his/her ability to provide informed consent, comply with the follow-up requirements, or provide self- assessments is compromised (e.g. homeless, developmentally disabled and prisoner).
19. Is a relative of the Investigator or an employee at the clinical study site.