What Are The Dangers Of Diets?

Dieting first gained mass appeal in the early 1800s when Presbyterian minister Sylvester Graham launched a vegetarian diet, supplemented by graham crackers and caffeine-free beverages, notes Andrew F. Smith, author "The Oxford Companion to American Food and Drink." Since then, the list of diets has grown long, ranging from plans that limit you to cabbage soup or grapefruit to restricting carbohydrates and allowing for plentiful amounts of fat. Americans spend over $40 billion on diet programs annually, according to the National Eating Disorders Association, or NEDA, and many of them pose potentially serious risks.

Slowed Metabolism and Weight Gain

Ninety-five percent of dieters regain lost weight, according to NEDA. Calorie restriction forces your body into starvation mode, meaning it holds onto calories consumed. This slows your metabolism, or the rate at which your body converts food into energy, and makes it easier to gain weight. If you lose weight, regain it, and then diet again -- a scenario known as "yo yo dieting" -- your metabolism may be damaged long term. Diets that pose strict rules may be difficult to follow, causing you to give up or causing excessive hunger, which may lead to overeating and weight gain.

Gallstones and Irregular Heartbeat

Gallstones are pebble-like deposits that form in your gallbladder that may cause abdominal cramping, yellowing of your skin and eyes, fever, uncomfortable fullness, nausea and vomiting. Surgical removal of your gallbladder is the typical treatment once symptoms arise. Eating a severely low-calorie diet and losing weight rapidly may trigger gallstones. If your diet involves severe calorie restriction -- eating fewer than 800 calories per day -- you also may develop abnormal heart rhythms, according to the Weight-control Information Network. This is a condition that may become fatal.

Depression and Anxiety

Diets can cause low blood sugar, which can disrupt your moods and energy levels, increasing your risk for irritability and depression. Depression among low-carb dieters has become so commonplace, according to Judith Wurtman, director of the Women's Health Program at the Massachusetts Institute of Technology, that it's been coined the "Atkins attitude." In an interview with "Psychology Today" in 2004, Wurtman explained that restricting carbohydrates lowers the levels of the feel-good brain chemical, serotonin. Low serotonin levels are linked with depression, anxiety and sleep problems. Personal or family history of depression or anxiety may increase your risk for these effects.

Nutrient Deficiencies

A balanced dietary lifestyle, sufficient in calories and nutrients, is important for maintaining and improving your overall health. Whether you restrict overall calories or particular nutrient groups, diets increase your risk for nutrient deficiencies and related complications. Dieters often consume too little calcium, for example, which increases the risk for osteoporosis and bone fractures. Consuming few omega-3 fatty acids -- prevalent in fatty fish, flaxseed, walnuts and canola oil -- can cause poor memory, skin dryness, fatigue, mood swings, heart problems, poor circulation and depression.