Final answer:
A fad diet is characterized by short-lived trends that promise quick weight loss but lack sustainability and balanced nutrition.
Explanation:
A fad diet is best described as short-lived because it often promises rapid weight loss, restricts certain foods, and is not sustainable for long-term health. These diets usually do not focus on overall balanced nutrition and can lead to health issues due to overconsumption of certain nutrients or rapid weight loss.
Learn more about Fad Diets here:
https://brainly.com/question/37878235
