Weight Loss Per Week On A Low-carb Diet

Many dieters claim to lose weight very quickly on low-carbohydrate diets. MayoClinic.com cautions that losing 1 to 2 lbs. per week is a safe and steady rate of loss and that losing weight more quickly requires extraordinary effort and may be difficult to sustain over the long term. In theory, low-carbohydrate diets work differently than traditional calorie-controlled diets, which may account for the different rate of loss on low-carbohydrate diets.

Background

During the first part of the 20th century, conventional diet wisdom suggested that the only way to lose weight was to limit fat and calories. In 1972, Robert Atkins, M.D., wrote "Dr. Atkins Diet Revolution." In the book, Atkins described eating "luxurious" foods such as lobster, steak, bacon, heavy cream and butter while losing weight. Dieters who were tired of low-fat foods tried the new way of eating and reported quick weight loss success. In 1992, Atkins introduced a new generation of dieters to low-carbohydrate diets with "Dr. Atkins New Diet Revolution," and many similar diets soon followed. Low-carb diets have been widely criticized by the medical community, leading to many studies testing the efficacy of the diets.

Identification

Low-carb diets restrict carbohydrate intake to significantly lower levels than traditional diets. For instance, Atkins restricts carbohydrate levels to less than 20 g per day during the initial phases of the diet. Carbohydrates contain sugars. When you eat carbohydrates, they cause your blood glucose levels to rise. Rice, potatoes, baked goods, candy, table sugar, some fruits and starchy vegetables are all high-carbohydrate foods that are restricted on low-carb diets.

Theories/Speculation

Your body normally burns carbohydrates as fuel, but Atkins suggests that when you limit carbohydrates, your body begins to use stored fat as its primary source of fuel. The state of burning stored fat as fuel is called ketosis. In his book "Good Calories, Bad Calories," Gary Taubes explains that the key to fat loss on a low-carbohydrate diet is insulin control. When your blood glucose rises in response to eating carbohydrate-laden foods, your body releases insulin. Insulin is a hormone that causes foods to be stored as body fat and prevents your fat cells from releasing fat as fuel. By controlling carbohydrates, you are controlling insulin. This allows your body to burn stored fat as its primary source of fuel.

Rate of Loss

Atkins suggests that you can lose as much as 15 lbs. during the first two weeks of the diet, followed by steadier weight loss of about 1 to 2 lbs. per week. This rapid initial weight loss is most likely due to water weight loss as your body's stored carbohydrates are depleted. According to the National Naval Medical Center in Bethesda, Maryland, carbohydrates are three parts water to one part carbohydrate, so as you deplete carbs, you are also depleting the water that is stored with them, which leads to rapid initial weight loss.

Research

A 2003 Ben Gurion University Study published in "The New England Journal of Medicine" assessed the rate of weight loss of low-carb and low-fat diets by following participants on both types of diet for a year. The study concluded that the low-carbohydrate diet led to approximately 4 percent greater weight loss in the first three to six months of the diet; however, after a year, both types of diets led to similar amounts of weight loss in both groups.

Considerations

While you may be able to lose weight rapidly during the initial few weeks of the diet, weight loss tends to even out as you continue forward with the diet. Atkins describes weight loss plateaus, which anecdotal reports suggest occur frequently on low-carb diets. These frequent plateaus may account for similar rates of weight loss in low-carb and low-fat diets despite the rapid initial loss on low-carb diets.