Weight Loss Fast Facts, Last Updated:09/06/2010
Atkins encourages controlling
carbohydrate
intake, and encouraged meats, nuts, unsweetened fruits, berries and
green vegetables. This causes rapid weight loss for many people,
although it continues to be disputed whether this is due to a
metabolic advantage of ketosis, as Atkins claimed. Some of the initial rapid
weight loss is due to depletion of glycogen stores in the liver.
Glycogen must be associated with several times its weight of water
in the body. Low carbohydrate diets have been shown to reduced the
fasting levels of triglycerides. Elevated triglycerides are a
demonstrated risk factor for heart disease and also account for
part of the risk of low density cholesterol due to their associated
worse particle size profile. Any successful diet for losing weight
will cause some ketosis, since ketones are produced when the body
is using fat energy to synthesize glucose (gluconeogenesis) during
the long overnight fast (sleep). Elevated levels of fasting
triglycerides (TGs) are the product of de novo lipogenesis
(synthesis of new fats) from glucose substrate. If the liver was
engaged in gluconeogenesis from fat, and synthesizing fat from
glucose at the same time, this would be a futile cycle, and a
fantastic way to waste energy and lose weight. For most of human
history, it has been important to survival to avoid such
inefficiency, so the body switches modes to avoid this futile
cycle. This explains the dramatic reductions in fasting TGs seen in
many low carbohydrate dieters. |
