question: INTRODUCTION Obesity and type 2 diabetes (T2D) are two closely related pandemic conditions. Novel technologies represent promising tools for their management, the use of which has been greatly encouraged during the COVID-19 pandemic. The aim of the present study is to compare a web-based nutritional intervention versus a traditional one, before and during the Italian 'lockdown' period due to the COVID-19 outbreak, in overweight and obese subjects affected by T2D or impaired glucose regulation (IGR). METHODS For the study, 36 subjects were randomly allocated into two arms: a traditional arm, providing face-to-face individual and group-based intervention; and a web arm, deploying the in-presence traditional approach with intervention provided through web technologies. The outcomes were the data resulting from the comparison between the subjects' anthropometric and clinical parameters as well as PREDIMED scores at baseline with those at 3 months (T3), 6 months (T6) and at lockdown. RESULTS In the web arm we detected a progressive reduction in weight and body mass index (BMI) from baseline to T6 and a minimal increase of both parameters during the lockdown. Improvement of these parameters compared with baseline was observed in controls during the lockdown. The PREDIMED score improved at T6 compared with baseline in both arms. Significant variations were observed considering weight (p < 0.001), BMI (p = 0.001) and PREDIMED scores (p = 0.023) over time. DISCUSSION The study showed the effectiveness and feasibility of a short-term nutritional web-based intervention in patients affected by T2D or IGR before and during the COVID 19 pandemic.Clinical Trial registration number: NCT04386200, ClinicalTrials.gov.