Each NutriBlast recipes is designed for the 24oz cup unless otherwise noted. If using as a meal replacement, we suggest drinking the whole cup so that'd be one serving. However, the amount you should drink is up to you and depends on your daily caloric needs, your appetite, activity level and the other foods you consume during the day! My best advice is to follow your hunger-fullness cues. If you can't finish the whole thing simple put the lid on the cup, store it in the fridge and drink the rest within 24 hours.