Final answer:
Eating only cold, green foods for one month would be considered a fad diet.
Step-by-step explanation:
A fad diet is a type of weight loss diet that becomes popular and then quickly loses popularity. It often promises quick results but may not be based on sound nutritional principles. Of the options provided, Eating only cold, green foods for one month would be considered a fad diet. This type of diet restricts food choices unnecessarily and lacks the balance and variety needed for long-term health.
Learn more about Fad diets