Tipping the Scale

Benefits: This easy-to-follow diet eliminates sugars and highly processed starches, which tend to be calorie-dense, but limited in nutrients. People can therefore lose weight and feel successful quickly. Short-term results have shown that some people experience a drop in blood lipid and glucose levels, which can lead to decreased risks of chronic diseases like atherosclerosis, heart disease and diabetes. The problem is these results do not last when people are on the diet for an extended period. Drawbacks: Due to excessive protein intake and the severe restriction of carbohydrates, much of the weight loss is water, which puts undo strain on the kidneys. And since carbohydrates are the primary fuel source for the brain, the diet negatively effects mental clarity and cognitive functioning. In addition, it creates an environment for bone loss and intestinal complications. The diet's restriction of fruits, vegetables and whole grains could translate into deficiencies in vitamins, minerals, phytonutrients and fiber. Lastly, the eating plan is dangerously high in total fat and saturated fat content, risk factors for chronic diseases. Long-term success: Recent objective data suggests weight loss can be the short-term result, with weight gain and an increase in blood lipid and glucose levels occurring when following the diet long term. Because the diet is so limited, many people discontinue it, and when they reintroduce carbohydrates into their diets, extreme weight gain ensues. The diet is not conducive to long-term compliance, with many people reporting feelings of depression and general malaise.

Fit for LifeOriginating in the 1980s, this diet by Harvey and Marilyn Diamond focuses on food combining and claims that certain foods when mixed are difficult to digest and absorb. Hence, food becomes fat. Benefits: Fit-for-life program is a fairly balanced one, with the focus on patient education as opposed to rigid restrictions that are -- in my opinion -- "fated to fail." The discussion of food selections and timing of certain food consumption is interesting (for example, if you are hungry, you may have fruit three hours after dinner). I am not convinced that this advice really promotes well-being. But if it tempers total caloric consumption, there is a benefit. Finally, as always, the encouragement of exercise -- any form -- is great. Drawbacks: Meal timing -- The diet calls for fairly liberal fruit consumption and only fresh fruit, fruit juices, preferably melon, all before noon -- odd details that will confuse some dieters. The diet discourages vitamin consumption with "proper food choices," but I personally do not discourage a multivitamin, one a day (not multiple pills), at times of dietary change. Long-term Success: Weight loss should not be extreme, but steady. Medically, we target 1/2 lb. to 2 lbs. maximum per week which equals approximately 3600-calorie loss a week for the mildly overweight patient. More rapid weight loss is not usually recommended unless the patient is morbidly obese.

Grapefruit DietDifferent versions of this Grapefruit Diet plan are available, but the idea behind every plan is the same: Eat half a grapefruit before every meal to enjoy the benefits of its fat-burning enzymes. It is also recommended that participants drink about eight glasses of water per day, along with unlimited amounts of black coffee. Benefits: This diet is so old, but continues to resurface, as they all do. It is easy to remember and follow (if you don't mind existing as a robot) without needing much thought or decision-making. Grapefruit is a good source of beta carotene, flavonoids and vitamin C. Drawbacks: The diet contains too much of the same foods, and lacks nutrient balance. It is extremely low in carbohydrates, and potentially high in fats -- particularly saturated fats -- because there is no recommended portion control or calorie limits. It is not even close to being scientifically based. There is no magic to grapefruit as a "fat burner." There are so many red flags for this being junk science. The diet promises extreme amounts of weight loss in a short time, which is dangerous to every system of the body. South Beach DietDr. Arthur Agatston's weight-loss advice focuses on a healthy balance between good carbs and fats. Decreasing the bad carbs, according to Agatston, will help metabolize what you eat more effectively and will also improve insulin resistance, leading to weight loss. Highly processed foods like baked goods and soft drinks are off-limits.

Benefits: It works! The principle is to transform the way most of us eat (large quantities and large portions of starchy foods). It starts you back from scratch and builds a healthy combination of fruits, vegetables and whole grains. This is what us registered dietitians call a normal, healthy diet! Drawbacks: It gives many individuals the wrong idea. Numerous people believe it's OK to stay in that low-carb stage for long periods of time. The research shows the damage this can do to one's body. Don't forget, most of us need a minimum of 50 to 60 percent of our calories from carbs! Long-Term Success: It helps to teach people a healthier way of eating. By the last "phase" of the diet, and into the "maintenance" phase, people are encouraged to choose more whole-grain foods. In essence, they are taught how to identify the "good" carbohydrates (complex whole grains) and limit the "bad" ones (simple sugars). Next: Sugar Busters >