Low-Carbohydrate Diets

Introduction

The use of a low-carbohydrate diet is based on the premise that too many carbohydrate-rich foods in our diet excessively raise the body's blood sugar, ultimately leading to increased body fat and weight gain. By this theory, restricting carbohydrate-rich foods will lead to weight loss. Whether this type of diet reliably leads to weight loss, however, remains controversial.

Purported Origins of Low-Carbohydrate Diets

The concept of low-carbohydrate dieting is not new. According to one account, the idea dates back to England in the 1860's and to an undertaker named William Banting. Banting was cursed with a familial tendency towards obesity which struck him hard while still in his thirties. He sought the best medical advice at the time, which told him to increase his bodily exertions and to eat "light food," whatever that meant. He repeatedly went to spas for treatment and even tried near-starvation diets but to little if any effect. In his sixties he was still fat, and suffering from a variety of ailments when an Ear-nose-and-throat doctor he was consulting for an ear problem, happened to tell him of recent research from Paris. This new theory tried to tie together diabetes, obesity, the liver with the sugars and starches in our diet. The ENT doctor thus prescribed a diet free of bread, butter, milk, sugar, beer and potatoes. This, of course, still left ample foods that he could eat and Banting took to the diet religiously. By the end of a year, he was down from 202 pounds to 156 and feeling much, much better. However, that wasn't the end of the story, because Banting was enterprising man who went on to publish a pamphlet entitled Letter on Corpulence, the first two editions of which were distributed free, lest he be accused of being a profiteer. Despite howls of protest from the medical establishment, the diet was widely popular, so much so William Banting was immortalized by having his name termed into a verb. People following the diet would be said to "Bant" or to be "Banting," a usage that was sustained into the 20th century.

The Atkins Diet

It wasn't until the 1960's that the idea of a low-carbohydrate diet was popularized again by the Atkins Diet, which waxed and waned in popularity until becoming a mass-market sensation in the 1990s. The Atkins' diet severely limits carbohydrates, and is essentially a high-protein, high-fat diet. It is based on the belief that diets high in sugar and other refined carbohydrates increase the production of insulin. This excess insulin then leads to storage of calories as fat. This diet severely restricts the consumption of carbohydrates, forcing the body to use fat as a fuel source. In its restrictions, the Atkins' diet has been shown to produce weight loss, but at the cost of eliminating important food groups, such as grains, fruits and dairy products.

Other Popular Low Carbohydrate Diets

Currently there are several other low-carb diets which are popular and not as restrictive as the original Atkins Diet. Some of these are the South Beach Diet, the Zone Diet, and Protein Power. These diets tend to allow what are sometimes called "good carbohydrates" into the diet. These are carbohydrates, such as green vegetables and berries, which do not tend to rapidly and severely raise the blood sugar. These carbohydrates are also known as low glycemic index carbohydrates. Because of the fewer restrictions, these newer diets tend to be easier to follow.

Controversies

There remains controversies among nutrition and diet experts as to "best" diet for losing weight. For years up until Atkins hit the scene, the nearly universal recommendation was that a low fat diet was neccessary to reduce body fat. Also, a low fat diet was thought to help reduce cholesterol and other lipids in the blood. Indeed, it seemed logical to reduce dietary fat intake to lose weight since fat has about twice the calories per ounce than protein or carbohydrates. However, as these low-carb diets became more popular, several medical research centers set up trials to compare weight loss among the varies popular type of diets. Duke University, for example, reported a study^[1] in the July 2002 issue of the American Journal of Medicine showing a sustained 10% average weight loss in patients on low-carbohydrate diet. A comparative study^[2] of the low-carbohydrate diet to the conventional low calorie, low fat diet was published in 2003 in the New England Journal of Medicine that suggested a modest (4%) greater weight loss than did the conventional diet for the first six months, but the differences were not significant at one year. The study also found a greated improvement some risk factors for coronary heart disease on the low-carbohydrate diet. Furthermore in 2008, another study^[3] in the New England Journal of Medicine comparing the conventional low-fat, low calorie diet to low-carb, no calorie restricted diet and to the typical Mediterranean diet. The low-carb diet was clearly superior in this study.

And yet, there are other fairly recent studies which indicate little difference between conventional low-fat diets and low-carb diets (See a 2003 review^[4] by Dena M. Bravata, MD, MS, in: Journal of the American Medical Association) Bravata did a review of low carb research between 1966 and 2003 found the evidence to be neutral. And,the [www.americanheart.org American Heart Association] still promotes the conventional low fat, calorie-restricted diet for weight loss and heart health.

References

1. ↑ Westman, Eric C et. al. "Effect of 6-month adherence to a very low carbohydrate diet program." The American journal of medicine 113 (2002): 30-6 - Abstract
2. ↑ Foster, Gary D et. al. "A randomized trial of a low-carbohydrate diet for obesity." The New England journal of medicine 348 (2003): 2082-90 - Abstract
3. ↑ Shai, Iris et. al. "Weight loss with a low-carbohydrate, Mediterranean, or low-fat diet." The New England journal of medicine 359 (2008): 229-41 - Abstract
4. ↑ Bravata, Dena M et. al. "Efficacy and safety of low-carbohydrate diets: a systematic review." JAMA : the journal of the American Medical Association 289 (2003): 1837-50 - Abstract