Of protein, carbs and fats, fat is the only macro that doesn't elicit an insulin response.
100% pure cream it contains only fats (provided contains no additives/thickeners), so does not spike your insulin levels or break a fast so this can be had even between meals and fasting periods on board your program.
We would suggest a serving of one to two teaspoons in your coffee or tea.
Adding cream to your coffee/tea will also make you feel full throughout the morning!