1 quart (32 oz.) vanilla low-fat yogurt
12 ounces frozen lemonade concentrate, thawed
1 cup half-and-half
1/4 cup lemon juice
1/2 cup sugar
1. In a bowl, whisk together yogurt, lemonade concentrate, half-and-half, lemon juice, and sugar until sugar is dissolved. Chill until cold, about 30 minutes.
2. Freeze mixture in an ice cream maker (1 1/2-qt. capacity) according to manufacturer's instructions, until motor stops or dasher is hard to turn. Transfer to an airtight container and freeze until firm enough to scoop, about 2 hours.