A new weight-loss trend going viral on TikTok promotes eating only watermelon for several days. While the fruit is hydrating and full of potassium, experts warn that relying on it alone can lead to health risks. Physicians say the diet lacks essential nutrients like protein, fiber and fat, which are needed for muscle function and energy.

Dr. Mark Hyman says the watermelon diet may cause quick weight loss, but it's mostly water and muscle, not fat. He cautions that the body needs a balanced diet for real, lasting results. Dietitian Ilana Muhlstein agrees, noting that while the fruit may reduce bloating, extreme use can cause muscle loss and electrolyte imbalance.

Both experts say watermelon can be part of a healthy diet, but eating only one food for days is not a safe or effective way to lose weight. A better approach includes a mix of whole vegetables, protein, fiber, and proper hydration.