Low-Carb Diets and Foods

JULY 01, 2004
Max Sherman, BSPharm

Obesity is fast becoming America's number-1 health problem. According to recent figures, 64.5%, or about 127 million people, are overweight. The incidence of obesity has doubled in the past 20 years.1 One expert blames this trend on a National Institutes of Health Conference in the mid- 1980s that decreed that all Americans should reduce their fat intake from 40% to 30% of their total daily calories.2 The Food Guide Pyramid, released shortly thereafter, called for 6 to 11 servings of bread, cereal, rice, and pasta daily, while fats and oils were to be used "sparingly." American companies began to introduce thousands of low-fat products full of carbohydrates as their answer to the call for sensible dieting.

The aftermath is that today approximately 45% of women and 30% of men are attempting to lose weight. In many cases, dieting has become an obsession. "Low-carbohydrate" rather than "low-fat" diets are now the latest craze. There are at least 14 popular diet plans. Within the past several months, a plethora of advertisements has appeared touting their benefits. Pharmacists are certain to be asked about them.

The diets are the result of best-elling books written by Drs. Robert Atkins and Arthur Agatston, among others. Dr. Agatston has created what he calls the South Beach Diet. It is somewhat similar to the diet proposed by Dr. Atkins. Both diets restrict carbohydrates—which means that dieters must refrain from eating potatoes, bread, fruit, cereal, rice, pasta, beets, carrots, and corn for the first 2 weeks. Alcohol also is forbidden in the induction phase and is limited in the long-term diet. The South Beach Diet and some others distinguish between low- and high-sugar carbohydrates. Low-sugar carbs (those with a low glycemic index) are permitted.

The Carbohydrate Dilemma

The problem with overconsuming refined or high-sugar carbohydrates is that amylase, an enzyme, quickly converts them into glucose. This process causes the pancreas to overproduce insulin, the substance that conducts glucose into the cells. Unfortunately, excessive glucose is toxic to cells, and, after years of glucose and insulin overload, the cells can become insulin-resistant and may no longer allow insulin to easily push glucose inside them. Blood glucose levels become high, and in response the pancreas must make even more insulin in an attempt to insert glucose through cell membranes.

High insulin and glucose levels eventually affect the pancreas, so that it can no longer produce insulin—and the result is type 2 diabetes. The high levels of insulin and glucose also increase the risk of coronary heart disease, hypertension, liver disease, polycystic ovary syndrome, and several types of cancer.2

The Atkins Diet

Dr. Atkins' plan is the antipode of the food pyramid. It consists of 4 phases. Phase 1 is Induction, and its purpose is to induce weight loss by changing the body's chemistry to achieve lipolysis with secondary ketosis. The Atkins Diet seeks to change a person from a sugar-burning- to a fat-burning-for-energy machine. This phase is the most difficult, because it is designed to break down a person's addiction to sugar, wheat, corn derivatives, alcohol, caffeine, and certain grains. It lasts a minimum of 14 days.

Phase 2, termed Ongoing Weight Loss, is designed to establish a Critical Carbohydrate Level for sustaining lost weight. This phase allows the dieter to begin eating certain fruits while controlling the consumption of carbohydrates.

Phase 3 is the Pre-Maintenance period. This phase bridges losing and then maintaining weight. Other foods may be added to the diet.

Phase 4 is called Maintenance. It begins when dieters have reached their goal weight. Certain foods still are forbidden, to prevent a return to the old eating habits.

The South Beach Diet

According to its Web site, the South Beach Diet is not classified as a low-carb or a low-fat diet. It teaches dieters to select the right carbohydrates and fats and to eschew bad ones. The developer of the diet, Dr. Agatston, declares that followers will lose between 8 and 13 pounds in the first 2 weeks. Like the Atkins diet, this diet has phases, but only 3.

In Phase 1, the strictest phase, dieters can consume normal-size portions of meat, chicken, turkey, fish, and shellfish. In the first 14 days, as with the Atkins Diet, bread, rice, potatoes, pasta, fruit, and baked goods are taboo, as well as candy, cake, cookies, ice cream, alcohol, and sugar.

In Phase 2, a more liberal phase, some carbohydrates are permitted, but in moderation. The proponents of this diet promise that people will continue to lose a pound or 2 a week on average.

In Phase 3, or the weight-maintenance phase, normal foods are allowed in normal-sized portions. Because Dr. Agatston is a cardiologist, he has said that this diet promises to alter blood chemistry and to benefit the cardiovascular system.

Low-Carb Foods

Subway, Burger King, McDonald's, and other fast-food enterprises now offer low-carb foods. Grocery stores, health food stores, and many pharmacies stock low-carbohydrate breads, pancake flours, cereals, and other offerings. Casual-dining restaurants, such as Ruby Tuesday and T.G.I. Fridays, recently have added low-carb options to their menus. The option may be as simple as having a burger served in a wrap rather than on a bun. There are more than 20 companies listed on the Web site synergydiet.com, selling everything from soups to "gummy bears" candies.

More than 100 products now bear the Atkins trademark, each with a small number or 0 g of net carbohydrates per serving. Breakfast bars, condiments, bakery items, cereals, and flours are available. Keto, for example, is a major manufacturer of low-carb foods and snacks, including shakes, bread and drink mixes, pastas, potatoes, fruit, desserts, and pizza dough. For the gourmet diner, the potatoes, termed "Ketatoes," are available in 3 flavors.

Another popular product line is supplied by EAS. This company provides low-carb nutritional shakes and energy and nutrition bars. Carbolite is another major supplier of low-carbohydrate foods. It specializes in snack foods, including chocolate bars, other candy, cereal bars, cookies, and meal replacements.

Information for the Pharmacist

Because Americans are now obsessed with reducing carbs, pharmacists may be asked to describe or define carbohydrates, the benefits of low-carb diets, glycemic index, and body mass index. Carbohydrates are defined as neutral compounds of carbon, hydrogen, and oxygen, mostly formed by green plants. Those that are highly processed, such as sugar and white flour (the so-called "bad carbs") are digested too quickly. Thus, insulin levels suddenly rise, and individuals crave more food, usually more carbohydrates.

Low-carb diets induce weight loss by changing body chemistry from a carbohydrate-burning metabolism to one that primarily burns fat for energy. According to the Atkins Web site, the diet also is designed to stabilize blood sugar and to abruptly halt a myriad of symptoms indicative of unstable blood sugar, such as fatigue, mood swings, and "brain fog."3

Despite the popularity of the low-carbohydrate, high-protein, high-fat diet, no randomized, controlled trials have evaluated its efficacy.4 This fact is surprising in light of the longevity of the Atkins Diet.5

Recently, a 1-year scientific study was conducted comparing the Atkins diet with a low-calorie, high-carbohydrate, low-fat (conventional) diet. The Atkins diet (which initially limited carbohydrate intake to 20 g per day) produced a greater weight loss than did the conventional diet for the first 6 months, but the differences were not significant at 1 year. The low-carbohydrate (Atkins) diet was associated with a greater improvement in some risk factors for coronary heart disease, but, according to the study authors, longer and larger studies are required to determine the long-term safety and efficacy of the Atkins diet.6 The study was marred because large percentages of patients were lost to follow-up.7

A longer study is planned comparing the Atkins diet with a conventional diet. Besides weight loss, lipid levels, bone density, and kidney function also will be measured.

The glycemic index measures how fast a food is likely to raise blood sugar. Glucose is given an arbitrary value of 100, and other carbs are given a number relative to glucose.

Body mass index is the accepted way of calculating whether or not a person is overweight or obese; 25-29.9 is considered overweight, and over 30 is obese. The index is calculated by dividing weight in kilograms by the square of height in meters. A number of Web sites contain information to facilitate the calculation.

Final Thoughts

Pharmacists should know that "lowcarb" does not mean "low-calorie." Many dietitians believe that it is more important to count calories than grams of carbohydrates.

According to the Pharmacist's Letter, both the Atkins and South Beach diets help some people by reducing food intake, and eating fats and protein reduces hunger.8 There are, however, no scientific data to verify long-term effects. More information is needed to determine whether the beneficial effects of the Atkins or a similar diet outweigh their potential adverse effects on the risk of coronary heart disease in obese patients. More balanced diets would appear to be preferable. The LEARN Program for Weight Management 9 and the dietary recommendations from the Department of Agriculture Food Guide Pyramid 10 are good choices.

Obese patients should not expect any miracles. They should focus instead on eating less, eating better food (ie, fruits, vegetables, fiber), and getting enough exercise.

Pharmacists should consider learning more about nutrition and becoming "diet advisers." A good way to start is to read Living the Low Carb Life, written by Jonny Bowden. It describes each of the 14 diets mentioned previously and provides a number of helpful Web sites.11

Mr. Sherman is president of Sherman Consulting Services Inc.

For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. A. Stahl, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: astahl@mwc.com.