“Early June and January are the two times of year people do crazy, desperate things to get thin fast,” says Bacon, a nutrition professor at the City College of San Francisco and the author of Health at Every Size: The Surprising Truth About Your Weight. “They go on fasts, yo-yo diets, detox programs, and ‘cleanses’ without realizing that there are serious consequences to weight loss and nutrient restriction.”
That crash dieting doesn’t work and can be dangerous is a message that gets lost in the national clamor over rising rates of overweight and obesity. Thinking of trying a lemonade fast or cabbage soup diet? Here’s what to keep in mind if fitting into your skinny jeans or your Speedo is high on your summer agenda.
Crash diets may harm your heart
Cardiologist Isadore Rosenfeld, MD, a professor of clinical medicine at Weill Cornell Medical College, in New York City, and author of the forthcoming Doctor of the Heart: A Life in Medicine, opposes crash diets (less than 1,200 calories a day) and detox plans like the Master Cleanse. The Master Cleanse involves consuming a mixture of water, lemon juice, maple syrup, and cayenne pepperand nothing elsefor several days.
He says these very low-calorie regimens are based on the false theory that the body needs help eliminating waste.
Research suggests rapid weight loss can slow your metabolism, leading to future weight gain, and deprive your body of essential nutrients. What’s more, crash diets can weaken your immune system and increase your risk of dehydration, heart palpitations, and cardiac stress.
“A crash diet once won’t hurt your heart,” Dr. Rosenfeld says. “But crash dieting repeatedly increases the risk of heart attacks.”
Bacon adds that long-term calorie-cutting can eventually lead to heart muscle loss. “Yo-yo dieting can also damage your blood vessels. All that shrinking and growing causes micro tears that create a setup for atherosclerosis and other types of heart disease,” she says.
Chip Stinchfield, a 55-year-old shop owner in New Canaan, Conn., has experienced the cardiac effects of dieting firsthand. On the advice of friends, he went on a Master Cleanse for days and exercised vigorously. Another time he ate nothing but cottage cheese, beets, and peanut butter. Both were “quick, easy fixes” that helped him drop up to 10 pounds fast.
But both diets also gave him shortness of breath, heart palpitations, and “the feeling like I was going to have a heart attack.” Under pressure from his family, who thought his dieting might disable or kill himlike many extreme dieters, Stinchfield kept his doctor in the dark about his radical habitshe eventually went back to sensible eating.