Possible Clues:

• Polite turndown for desserts
• Small portion explanation
• "No dessert for me"
• Comment that might follow 'None for me, thanks'
• "No dessert for me today"
• 'No dessert for me today'
• "None for me, thanks"
• Explanation for passing
• Calorie counter's refrain
• Sad return on a sweet offer?