Atkins Diet & Carbohydrates

The human body has the ability to store fat as energy reserves--the same energy reserves that helped our ancestors survive famines. It can only store a limited amount of carbohydrates, enough for about half a day's energy supply. Consumed carbs are the body's primary and preferred fuel source. Given enough carbohydrates for sufficient fuel, consumed fat calories are stored in preparation for the next theoretical famine or drought. The Atkins Diet is based on the theory that if carbohydrate intake is restricted, the body will use its own fat for fuel with resultant weight loss.

Low Carbohydrate Diets

The theory behind low-carb diets is that without an ample supply of consumed carbs for fuel the body will turn to its stored fat reserves as its fuel source. When carbs are consumed they are digested and then converted to the sugar, glucose. The glucose is then transported throughout the body via the bloodstream and can be measured by a blood sugar test. Fluctuations in blood sugar levels are largely due to the type and amount of carbohydrates consumed. According to the Atkins official website, for most people, fat burning is initiated by cutting the daily net carb intake, obtained mostly from vegetables high in fiber, to 20g a day. This is the number of net carbs allowed during the first phase, called Induction, of the Atkins Diet plan. Net carbs, the only carbs necessary to count on the Atkins Diet, are determined by subtracting the fiber grams from the total carbohydrate grams in a specific food.

The Atkins Diet

The Atkins diet, a restricted carbohydrate diet plan developed by Dr. Robert Atkins, became popular with the publication of the book, "Dr. Atkins Diet Revolution," in 1972. The diet has four phases with the permitted amount of net carbs consumed progressively increasing. Theoretically, the fewer net carbs eaten, the greater the rate of weight loss.
Phase 1, Induction, switches the body to burning primarily fat instead of carbs. During this two-week phase, there is a limit of 20 net grams of carbs a day.
In Phase 2, Ongoing Weight Loss (OWL), more vegetables, nuts, seeds, legumes, melon and berries are added. The objective is for each person to find his own threshold for carb consumption, called the Carbohydrate Level for Losing (CLL). Weight loss slows as carbs are added, but still continues. Dieters remain in this phase until they are within 10 lbs. of their goal weight.
The focus of Phase 3, Pre-Maintenance, is for each dieter to find his Atkins Carbohydrate Equilibrium (ACE) by slowly adding carbs until a point of equilibrium is reached where there is neither weight gain or loss. The last 10 lbs. come off slowly as the body adjusts to the increased carb intake.
In Phase 4, Lifetime Maintenance, dieters have reached their goal weight and commit to maintaining it by learning to adhere to their carbohydrate equilibrium number.

How Atkins Works

According to the Atkins website, the body switches to burning primarily fat instead of using both carbs and fat for fuel when the balance of protein, carbs, and fats is changed. Atkins maintains that this is a normal metabolic process where the body begins to use fat as its primary energy source. A side effect of burning fat stores for energy is weight loss. When the body is given primarily protein, fat, and fiber foods it doesn't have to produce as much insulin as it would with a greater percentage of carbohydrate food. The role of insulin in the body is to direct glucose into cells and to control the release of the fat stored in the fat cells. On the Atkins Diet, the controlled amounts of high-fiber carbs convert to glucose slowly, reducing the likelihood of large fluctuations in blood sugar levels.

Benefits

Data from a randomized trial reported in "The Journal of Clinical Endocrinology and Metabolism" showed that for short-term weight loss, a very low carb diet is more effective than a low-fat diet. In healthy women studied over a six months, there was no relationship between the low-carb diet and harmful effects on cardiovascular risk factors. In a year long, multicenter randomized trial reported in the "New England Journal of Medicine," 63 obese men and women were randomly assigned to either a low-carbohydrate, high-protein, high-fat diet or a low-calorie, high-carbohydrate, low-fat (conventional) diet. The people on the low-carb diet had more weight loss than those on the conventional diet for the first six months, but at the one year mark the differences were not significant. The people on the low-carb diet showed more improvement in some coronary heart disease risk factors. The authors of the study recommended larger and longer term studies to determine the effectiveness and safety of low-carb, high-protein, high-fat diets.

Dangers

According to the Mayo Clinic, healthy adults generally handle short-term, high-protein diets well. However, a dramatic increase in protein-rich foods might be dangerous for people with liver or kidney disease because of possible trouble getting rid of the waste products produced by the breakdown of protein. There is potentially an increased risk of osteoporosis and of developing kidney stones with a high-protein diet. When following this type of diet, other healthy food groups, such as whole grains and certain fruits and vegetables are limited, and there could be overconsumption of protein foods that are high in fat and cholesterol.