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Feature Articles: Weight Loss

Are Low Carbohydrate Diets Worth It?

Sarah Janicek, BS, Barbara Willenberg, MS, Candance Gabel, MS, RD, LD, University of Missouri Extension

Bread vs. Protein on scale

What is a healthy diet? Grain products, vegetables and fruits should be the foundation of a healthy diet. Eating foods that are moderate in sugars, salt and sodium, while also being low in fat, saturated fat and cholesterol will ensure proper nutrition. A diet that is full of variety will keep Americans healthy.

What is a low carbohydrate diet? Most popular low carbohydrate diets have a 1- to 2-week period when carbohydrates are restricted to 20 grams or less per day. Carbohydrates are slowly reintroduced into the diet after the first two weeks until weight is maintained. The recommendation is to consume at least 130 grams per day. Although low carbohydrate foods are restricted on these diets, eating foods high in protein and fat is advised.

How do you lose weight on a low carbohydrate diet? Because these diets restrict carbohydrates (a major source of energy in the diet), the body begins to break down muscle tissue for energy. When this occurs water is released causing a diuretic effect. The rapid weight loss in the first two weeks on these types of diets is due to water loss, not fat loss. After the first two weeks the weight loss will continue, but it is because of calorie restriction from the reduction of carbohydrates consumed.

What are the consequences from these diets? When the body is not getting enough energy from food, and has depleted its storage of energy from the muscles, it will resort to breaking down fat tissues. When body fat is broken down for energy, byproducts called ketone bodies are released into the bloodstream causing a condition known as ketosis. This is an unnatural state for the body, resulting in weakness, nausea, dehydration, light-headedness, irritability and a decrease in appetite. Prolonged ketosis may leach calcium out of the bones, increasing the risk of osteoporosis.

Because low carbohydrate diets are usually high in total fat, saturated fat and cholesterol, the risk for developing heart disease and some forms of cancer is increased. These diets also encourage high protein intake which puts an enormous strain on the liver and kidneys, especially for people with diabetes who are already at risk for diabetic kidney disease. The restriction on carbohydrates limits the amount of fruits, vegetables and grains consumed, therefore causing constipation and increasing the risk of developing some types of cancers.

After the diet has ended, people often gain back the weight they lost, if not more. When carbohydrates are reintroduced into the diet, the body will store them as fat as a result of ketosis. Muscle mass is metabolically active (meaning it burns calories even at rest), but, because it was lost while on the diet, the metabolism slows down significantly. Therefore, a decrease in calories is needed in order to maintain weight.

What are the recommendations for healthy weight loss? The most effective, safe and long-term way to lose weight includes eating a balanced diet combined with participating in regular physical activity. In order to lose weight effectively, the amount of calories consumed must be less than the amount burned (i.e., physical activity). The results may be gradual, but they are proven to be safe; and the weight loss will be long-term as long as lifestyle changes are made.



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Last update: Tuesday, May 05, 2009








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