During the first phase of the Atkins Diet, a 14-day period known as "induction," dieters restrict their consumption of carbohydrates to 20 g or less per day. The regimen, introduced by Dr. Robert Atkins in the 1970s, forces the body to burn through its glycogen reserves -- that is, carbs stored in the muscles and liver -- and switch to burning fat for energy. Atkins dieters sometimes refer to "induction flu" to describe common first-stage side effects, which can include constipation, food cravings and leg cramps.
Glycogen Depletion
It takes the body about two days to burn through its glycogen stores when deprived of carbs, according to "Dr. Atkins' New Diet Revolution." Dieters embarking on phase one subsist primarily on animal proteins such as eggs, poultry, fish, pork, beef and lamb, accompanied by up to three cups per day of salad and certain vegetables, plus liberal use of fats such as butter and olive oil. Once the glycogen is gone, the body switches from glycolysis, or burning sugars for fuel, to lipolysis, or burning fat, according to Atkins' theory.
Hydration
Because carb molecules hold on to water, and because protein and fat require more water to digest than carbohydrates, the Atkins induction phase produces a pronounced diuretic effect, which might be amplified if you also restrict sodium intake. "Starting any weight loss program has a diuretic effect, which is one of the reasons it is so important to stay hydrated," writes Dr. Atkins, who reports that men lose up to 10 lbs. during induction, and women about 6 lbs., a third of which can be water weight. "If you have leg cramps, it probably means you are losing too many electrolytes, which are full of minerals." The Atkins program encourages dieters to consume no less than eight 8 oz. glasses of water daily. Carb-counting applications for Smartphones and tablet computers usually track water consumption as well.
Prevention
In addition to maintaining proper fluid intake, Atkins dieters can help prevent leg cramps by avoiding caffeinated drinks, which produce a diuretic effect and are prohibited during the induction phase because of caffeine's ability to produce a hypoglycemic, or low blood sugar, reaction. To treat persistent leg cramps, Atkins also suggests supplementing your diet with potassium, magnesium and calcium, the electrolytes that regulate fluid balance in the body.
Potassium is particularly helpful. The USDA recommends that adults get 4,700 milligrams per day. Potassium supplements of more than 99 mg per dose are available only with a doctor's prescription as of June 2011, but Michael Murray and Joseph Pizzorno, authors of "Encyclopedia of Natural Medicine," recommend using a salt substitute. "So-called salt substitutes ... are in fact potassium chloride, at a dosage of 530 mg of potassium per one-sixth teaspoon!" they write.
Outlook
During the second, third and fourth phases of Atkins -- ongoing weight loss, pre-maintenance and lifetime maintenance -- dieters gradually increase their daily intake of carbs by 5 g to 10 g each week. Nuts, avocados, and certain fruits and vegetables, such as tomatoes, potatoes and dried fruit, help replenish electrolytes quickly. As carb intake increases, leg cramps should become much less of a problem.
