Wed, 07 May 2003

Atkins Diet vs `conventional' diet

Melissa Southern-Garcia, Dietitian, Jakarta,

Dear Melissa, I have heard that you can lose weight if you stop eating bread and rice and eat only meat. Is this true? Thanks. --Lana

Dear Lana,

For quite some time now, there has been a debate in the scientific community about the validity of a low-carbohydrate, high-protein diet. This question has once again come to the forefront with the recent death of Dr. Robert Atkins, whose unconventional approach to nutrition and weight loss has sold over 15 million books and created a worldwide following for the famed "Atkins Diet".

In fact, a recent BBC series entitled Diet Trials included the Atkins Diet as one of the four most popular diets in the UK.

So what exactly is the Atkins Diet? This diet proposes that an individual stop eating almost all sources of carbohydrates such as sugar, starch, rice, breads and even fruits, while at the same time, eating fat and protein sources with virtually no restrictions. Dr. Atkins argued that carbohydrates are the main source of obesity, since the processed carbohydrates we normally consume are immediately transformed into glucose (sugar) in the body.

The increase in glucose in the blood stream in turn causes the pancreas to release insulin to control the amount of sugar in the blood. The more obese a person is, the more insulin the body is required to produce. When the body's cells are continually exposed to insulin, they can become resistant and if the body's own production of insulin becomes insufficient to keep blood sugar under control, a person suffers from diabetes.

However, Dr. Atkins argued that it was the constant surge of insulin in the blood from carbohydrates that caused obesity, since insulin also regulates metabolism. When insulin levels are high in the blood, the body burns carbohydrates for energy and stores fat.

It is only when insulin levels are low that fat can be burned. The answer to weight loss, according to Atkins, lay in replacing glucose (from processed carbohydrates in the diet) with a second source of energy: Stored fat. The basic concept is that a diet low in carbohydrates and high in fat and protein, would force the body to use stored fat in the body while avoiding problems with insulin and blood sugar levels.

The scientific community has long been against this type of diet, since it goes against volumes of research that prove that diets high in fat are a leading cause of heart disease, while diets high in grains, fruits and vegetables are the best way to decrease chances of heart disease and even many types of cancer.

So if these ideas are so unconventional, why are so many people around the world trying this or similar low-carbohydrate diets? One of the primary reasons for the success of this diet is that many people will lose weight. The question is, why do they lose weight, and what are the implications of following a diet like this for the long term?

When the body burns fat in the forms of its sub-units, called ketones, it uses a great deal of water and the body can easily become dehydrated. In fact, constipation is often a side effect of this type of diet, precisely because of dehydration. This water loss contributes significantly to the first visible weight loss for someone following the Atkins Diet.

Another reason following this diet may lead to weight loss is simply because it requires strict monitoring of foods eaten and it restricts major sources of calories, such as carbohydrates.

When you think about what you are eating and are conscious of your food choices, you can often make better ones. Hand in hand with this approach is the fact that protein and fat sources, such as meat, are heavier and can often produce a longer-lasting feeling of fullness.

Unfortunately, no studies have been conducted to test the long-term efficacy of the Atkins Diet. Many followers of the diet stop losing weight after the initial water weight loss. Others will gain the weight back, since avoiding carbohydrates is too difficult a task to accomplish for more than a short amount of time.

Many cardiologists and health professionals have also questioned the long-term health effects of incorporating virtually unlimited fat in a diet, as well as the problems caused by ketones.

In the short term, some people experience unusual breathing patterns, possible hair loss and fatigue. More long-term damage could possibly affect bones and kidneys due to an excess intake of protein.

Studies have shown conflicting information on the effect of the Atkins Diet on cholesterol. Although some studies indicate that cholesterol levels decreased in followers of the diet, others indicated that beneficial cholesterol (HDL) levels actually decreased as well.

Many of these changes in a person's cholesterol profile may be attributed to the simple fact that losing weight is proven to lower cholesterol independently of other factors. None of these changes can be considered significant, however, since the long- term effects of the Atkins Diet on cholesterol have yet to be studied.

Another significant drawback to the diet is that it recommends the virtual elimination of fruits and significantly limits the intake of legumes. One recommendation on the Atkins Diet web site instructs dieters to "eat absolutely no fruit" during the beginning phase of the diet.

During the later stages of the diet, the web site suggests looking at fruit as a "condiment or garnish". Fruits are sources of multiple vitamins, minerals, fiber and a countless variety of beneficial antioxidants that cannot be replaced by consuming protein-based foods.

Perhaps the answer to healthy weight loss lies in taking some of the positive aspects of the Atkins Diet and combining them with a conventional diet plan based on well-balanced meals.

Dr. Atkins' suggestion that sugary, refined foods should be avoided is a proposition that would benefit any diet. Choosing items that contain more fiber, such as nuts, seeds and whole grains, is also a sensible idea proposed by the diet. All calories in food come from one of three sources: Carbohydrates, protein and fat.

If a person follows the recommended low-fat diet, logically, that person will have to increase their intake of carbohydrates or protein to make up the difference. This is the point where wise nutritional choices play a part. Choosing the types of carbohydrates, fat or protein to include in your diet is the key.

Making wise high-fiber choices, including plenty of fresh vegetables and legumes, and choosing fats that are beneficial for your body, such as olive oil, avocados or nuts, will lead to a more sensible approach to dieting without the risks posed by diets that unnaturally restrict a major food group.