Whipping cream can work, it just has a lower fat content. Lower fat content means more lactose (sugar) which will make ketosis more difficult. Half-and-half has an even lower fat content and really a lot of sugar that will likely guarantee you won’t achieve ketosis.
Here are the calories and carbohydrate content for a 15ml/1 tablespoon “serving”:
|fat %||calories||carbs||carbs/400 calories|
|Heavy whipping cream||36.1||51||0.43||3.34|
|Darigold “Classic 40“||40.0||60||0.40||2.67|
Interestingly enough, all of the creams have less than 1g of carbs per “serving” so the package will say “0g total carbs” – even though the half-and-half has nearly 4x as many carbs per calorie compared to heavy cream. You have to muck around the USDA food database to get accurate nutrition information.