Weight Loss Facts

Dieting Snippet

Carbohydrate-restricted diets have become extremely popular. Previously, health professionals have speculated that these diets may have negative health effects, but we have not had a lot of research to see whether this is in fact true or not. Conversely the low carbohydrate proponents promise safe and quick weight loss.

At last we now have some research looking at the efficacy of these diets.

A recent study by Landers et al published in the J Okla State Med Assoc investigated the effects of three different diets, including a low carbohydrate-high protein diet (an Atkins type diet), the Zone diet and a conventional low energy diet, on weight loss and sustainability. Average weight loss was 5.1kg over 12 weeks, with no difference in total weight, fat or lean body loss between the diets. As for sustainability, the attrition rate for all 3 diets was high. 43 percent of dieters dropped out of the Atkins-like diet, 60% from the Zone diet and 36% from the conventional diets.

Another study published in the American Journal of Kidney Diseases found that 6 weeks on a low carbohydrate, high protein diet increased the acid load to the kidneys, raising the risk of kidney stones.

To further confuse the situation, a recently published study looked at the effects of a very low carbohydrate diet on biomarkers for cardiovascular disease. They found that this type of diet did not adversely affect cholesterol levels, and in fact actually improved some aspects of cardiovascular health. For example, fasting triglycerides (a measure of the amount of fat in the blood) and post-prandial lipemia (a measure of the rise in blood fat levels after eating), as well as fasting insulin levels were all significantly reduced after the men had followed the ketogenic diet for 6 weeks. However, those who followed the low carbohydrate diet lost a small but significant amount of weight (-2.2kg) as compared to the control group who gained on average (0.4kg). Furthermore, the individual responses in cholesterol varied with 4 subjects having lowered levels of LDL cholesterol (the "bad" cholesterol) compared to an increase in 7 subjects after following the low carbohydrate diet. This study needs to be repeated.