have a sweet tooth

have a sweet tooth (to like sugary foods; have a love for sweet foods) — злоупотреблять сладким; быть сладкоежкой, сластеной, лакомкой

Example 1: On my sister's birthday, I usually buy her something special from the bakery. These kinds of treats make her happy on any day of the year. She has a sweet tooth. (JenniferESL)
Example 2: People who have a sweet tooth tend to have more cavities. – Сладкоежки больше склонны к кариесу.