It's surprising how many common diet trends can cause serious harm. If you're tempted to quickly drop some pounds in time for summer beach season, here are 6 diets to avoid:

Unverified weight loss pillsDiet pills have gained popularity since the 1800s despite being notorious for toxicity and accidental deaths.• The FDA has already cited 300-plus dangerous weight loss, bodybuilding and sexual enhancement products.• Unsafe supplements cause 23,000-plus emergency room visits a year.• Hidden substances include medications, controlled substances and untested active compounds.Risks: Some of these pills have caused stroke, liver injury, kidney failure, heart palpitations, seizures and even death.The Grapefruit DietCreated in the 1930s with the misleading claim that grapefruit enzymes boost fat burning.• Diet limits followers to 800 calories a day.• Each meal starts with half a grapefruit.• Naringenin, an antioxidant in grapefruits, has anti-diabetic properties, but you'd need to eat 40 grapefruits (5,000 calories) in one sitting for any noticeable effects. • Grapefruits can be a healthy component of balanced diets.Risks: Malnutrition, photosensitivity, medication interactions. Grapefruit interacts with about 43 percent of all meds, causing severe effects like arrhythmias, kidney damage and gastrointestinal bleeding.The Cotton Ball DietWarning, this is extremely dangerous.Popularized in the YouTube videos and pro-anorexia websites around 2013, in which cotton balls are consumed in an effort to stop hunger.• "Meals" of up to five cotton balls dipped in orange juice, lemonade or a smoothie to stop hunger.• Seen most prominently in girls 9-16 years old.Risks: Choking, malnutrition, increased risk for eating disorders, life-threatening intestinal obstruction.The Master CleanseOriginally developed in the 1940s by Stanley Burroughs, and recently made popular by celebrities like Beyoncé.• Salt water, laxative tea and "lemonade" made of lemon juice, maple syrup and cayenne pepper are taken.• No evidence supports that cleanses lead to long-term weight loss.• Limit of 650 calories per day. Experts say dieters should never dip below 1,200 calories.• No evidence supports that cleanses lead to long-term weight loss.Risks: Mood swings, nausea, lean muscle loss, suppressed immunity, heart palpitations and low blood pressure.The Caffeine DietMade popular through marketing hype and celebrity endorsements of caffeine-related supplements like green tea extract.• Two cups of coffee may help you burn calories, but this doesn't work on people used to caffeine, no matter how large the dose.• Effects of 500+mg of caffeine can mimic stress, which signals the body to store fat.Risks: Stomach ulcers, accelerated bone loss, arrhythmias, muscle tremors cardiac arrest.The Cabbage Soup DietFirst appeared as a diet in the early 1900s and reappeared in the 1990s in trending fax and email messages.• Limit of 1,000 calories per day as cabbage soup, mainly causing water weight loss.• Lacks complex carbohydrates, protein, vitamins and minerals, and can be high in sodium.Risks: Stomach ulcers, accelerated bone loss, arrhythmias, muscle tremors, cardiac arrest.