Inclusion Criteria:  physician-diagnosed T1D or T2D of ≥1 year; current HbA1c of 6.5-8.5%; BMI: 25-40 kg/m2; blood pressure of <160/99 mm Hg assessed according to guidelines; non-smoking; not on hormone replacement therapy, corticosteroids, or anti-inflammatory medications; 18-75 years old.  Exclusion Criteria:  Are taking more than 2 glucose lowering medications; Are ongoing medical treatment for diseases such as cancer, auto-immune or inflammatory disease, liver or kidney disorders; Have allergy, intolerance or aversion to cocoa, stevia, erythritol, inulin, or any other dietary restrictions (e.g., vegan) that will prevent them from following the standardized study diets; Are unable to follow remote guidance by internet or smartphone; Are unable to follow the controlled diet instructions; Are unable to read or communicate in English.