Diets low-carbohydrate

Possibly the most serious nutrition problem in the United States is excessive food consumption, and many people have experimented with fad diets in the hope of losing excess weight. One of the most popular of the fad diets has been the high-protein, high-fat (low-carbohydrate) diet. The premise for such diets is tantalizing because the tricarboxylic acid (TCA) cycle (see Chapter 20) is the primary site of fat metabolism, and because glucose is usually needed to replenish intermediates in the TCA cycle, if carbohydrates are restricted in the diet, dietary fat should merely be converted to ketone bodies and excreted. This so-called diet appears to work at first because a low-carbohydrate diet results in an initial water (and weight) loss. This occurs because... 

MARSHALL J A, HAMMAN R F and BAXTER J (1991) High-fat, low-carbohydrate diet and the etiology of non-insulin-dependent diabetes mellitus the San Luis Valley diabetes study. J Epidemiol. 134 (6) 590-603. 

The ADA does not recommend low-carbohydrate diets in diabetes management. Although carbohydrates are a primary contributor to post-meal glucose levels, they are also an important source of energy, water-soluble vitamins, minerals, and fiber. Thus, the ADA recommends that carbohydrate intake consists of 45% to 65% of total calories. 

Reducing diets seem to come and go. At the time of writing the popularity of the Atkins diet seems to be decreasing. The Atkins diet is a low carbohydrate diet that is not conducive to the sales of baked products however, the Atkins diet seems to be being superseded by diets based on the principle of a low glycemic index. This is unlikely to increase the sale of baked goods but is less antipathetic to them. A new diet based on bread has appeared and so the wheel may go full circle. 

V American dietitians and members of the medical community have ridiculed low-carbohydrate diets as quackery for the past thirty years, while extolling a diet that cuts down on fat, limits meat consumption, and relies on carbohydrates as its staple. Many Americans are famil-(V iar with the food pyramid promoted by the U.S. government, with its foundation of carbohydrates such as breads, rice, and pasta, and its apex allotted to fats, oils, and sweets. Adhering to the government s... 

The author s attitude toward the medical experts who ridiculed low-carbohydrate diets as quackery and praised low-fat diets is one of... 

O Ketoacidosis is a dangerous condition that is characterized by the acidification of the blood and an acetone odour on the breath. The condition occurs when levels of oxaloacetic acid for the citric acid cycle are low. This leads to a buildup of acetyl CoA molecules, which the liver metabolizes to produce acidic ketone bodies. Since carbohydrates are the main source of oxaloacetic acid in the body, high-protein, low-carbohydrate diets have been linked to ketoacidosis. 

This is undoubtedly why low-carbohydrate diets have proved so effective for rapid weight loss. As soon as the reserves of carbohydrate are used up, the body resorts to metabolizing fat for its energy needs. This continues whenever carbohydrate intake is limited. It should also be appreciated that although carbohydrate can readily be converted into fat (via acetyl-CoA see Section 15.5), fat is not readily converted into carbohydrate in animals. Fat metabolism produces acetyl-CoA, which is then usually metabolized completely via the Krebs cycle. 

Acetone and several other ketones are produced in the liver as a result of fat metabolism. Ketone blood levels are typically about 0.001%. Lack of carbohydrates in a person s diet results in greater metabolism of fats, which leads to a greater concentration of ketone in the blood. This condition is called ketosis. People on low carbohydrate diets and diabetics have problems with ketosis because of their increase dependence on fats for metabolism. 

Use this site to explore the issues regarding high-protein, low-carbohydrate diets. 

Deficiency of pyruvate dehydrogenase is the most frequent cause of lactic acidemia ac Since this enzyme has several components (Fig. 15-15), a number of forms of the disease have been observed. Patients are benefitted somewhat by a high-fat, low-carbohydrate diet. Transient lactic acidemia may result from infections or from heart failure. One treatment is to administer dichloroacetate, which stimulates increased activity of pyruvate dehydrogenase, while action is also taken to correct the underlying illness.d Another problem arises if a lactate transporter is defective so that lactic acid accumulates in muscles.6... 

It is also important to note that a low-carbohydrate diet has the potential to have similar contaminant characteristics as a high-fat diet. 

It is clear from Equation (19.4) that saturated fat, not cholesterol, is the single most important factor that raises serum cholesterol. Some cases of hyperlipoproteinemia type IV (high VLDL) respond to low-carbohydrate diets, because the excess of VLDL comes from intestinal cells, where it is produced from dietary carbohydrate. Resins, such as cholestyramine and cholestipol, bind and cause the excretion of bile salts, forcing the organism to use more cholesterol. Lovastatin decreases endogenous cholesterol biosynthesis (see later), and niacin (nicotinic acid) apparently decreases the production of VLDL and, consequently, LDL. It also results in an HDL increase. Antioxidants that inhibit the conversion of LDL to oxidized LDL have also been used with some success. These are high doses of vitamin E and the drug probucol. 

Low-carbohydrate diets restrictthe intake of carbohydrates, sometimes resulting in rapid weight loss. The weight is lost because glycogen and fatty acids are burned to maintain blood glucose levels. 

Both low and high carbonydrate diets can increase exercise duration however, low carbohydrate diets may diminish the power output or VO2 max during exertion. Althouth diets high in carbohydrate or fat (low carbohydrate) may enhance exercise performance, it is recommended that a mixed diet be consumed by... 

B27, the HLA allele proposed to be involved in alkylosing spondylitis, shares an epitope with an enzyme from Klebsiella pneumoniae, a common intestinal Gram negative bacterium. Molecular mimicry is thought to result in cross-reactive antibody formation, joint inflammation and spinal damage. Along with many of the immunotherapies described for other similar arthritic autoimmune disorders, alkylosing spondylitis is treated with anti-inflammatory medications and a low carbohydrate diet to reduce intestinal K. pneumoniae levels. 

A patient with a hyperlipoproteinemia would be most likely to benefit from a low-carbohydrate diet if the lipoproteins that are elevated in the blood are... 

Our bodies only store a few days worth of carbohydrate, so a high-protein, low-carbohydrate diet can be risky for some people. Raw fruits and vegetables are the best sources of vitamins and minerals. We should be eating five or more generous helpings of fruits and vegetables every day. 

Low-carbohydrate, high-protein diets are popular these days, but consider the risks. Low-carbohydrate diets cause a significant (but temporary) loss of body water. When you get off the diet, the water returns. A low-carbohydrate, high-protein... 

The recommended daily carbohydrate intake for type 2 DM, and even type 1 DM, has become controversial since low-carbohydrate diets such as the Atkins, South Beach, and Carbohydrate Addict s Diets have become exceptionally popular. Currently, the ADA recommends that approximately 60% to 70% of daily caloric intake should come from carbohydrates and monounsaturated fat. Many clinicians are trying to increase the monounsaturated fat percentage and decrease the carbohydrate percentage in a patient s diet to accomplish improved glycemic control. Recent studies have also documented short-term success for weight loss on low-carbohydrate diets, without deleterious effects on the lipid panel. Weight loss can reduce cardiovascular risk factors in type 2 DM. 

Also, cattle fed on fatty foods such as coconut oil lost weight. And do not give up rich, meaty foods such as steak, eggs, prime ribs, lobster, bacon, etc. Instead of a carbohydrate burner, turn your body into a fat burner. In a way, the proposed diet is similar to Dr. Atkins low-carbohydrate diet, which in turn was similar to the thesis of the book titled Calories Don t Count, igniting a controversy that once ended up in court with a judgment against the book s authors. But it was a different world back then, in the 1960s. 

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