Dangers of Fasting for Weight Loss
Typical Fasting Weight Loss Plans
A systematic review of 62, participants in 10 dietary trials found that reducing dietary fat intake had no effect on coronary heart disease and had no effect on overall mortality. The authors of this meta-analysis conclude that the available evidence from randomized controlled trials does not support the recommendation of the - Dietary Guidelines for Americans that people reduce their fat intake. As with other diet plans, people who maintain a low-carbohydrate diet lose weight.
In persons with diabetes mellitus Type 2, a low-carbohydrate diet gives slightly better control of glucose metabolism than a low-fat diet. Potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol and total cholesterol values when low-carbohydrate diets to induce weight loss are considered.
As of it appeared that with respect to the risk of death for people with cardiovascular disease, the kind of carbohydrates consumed are important; diets relatively higher in fiber and whole grains lead to reduced risk of death from cardiovascular disease. High refined-grain diets do not. As of in commenting on a study in the Journal of the American Medical Association, a spokesperson for the American Dietetic Association reiterated the association's position that "there is no magic bullet to safe and healthful weight loss.
Fiction" campaign in , the ADA stated: Excess calories from carbohydrates are not any more fattening than calories from other sources. As of [update] the AHA stated categorically that it doesn't recommend high-protein diets. Some of these diets restrict healthful foods that provide essential nutrients and don't provide the variety of foods needed to adequately meet nutritional needs.
People who stay on these diets very long may not get enough vitamins and minerals and face other potential health risks. Eckel , past president, noted that a low-carbohydrate diet could potentially meet AHA guidelines if it conformed to the AHA guidelines for low fat content.
The position statement by the Heart Foundation regarding low-carbohydrate diets states: Low-carbohydrate diets became a major weight loss and health maintenance trend during the late s and early s. Because of the substantial controversy regarding low-carbohydrate diets, and even disagreements in interpreting the results of specific studies, it is difficult to objectively summarize the research in a way that reflects scientific consensus. Although there has been some research done throughout the twentieth century, most directly relevant scientific studies have occurred in the s and early s and, as such, are relatively new and the results are still debated in the medical community.
A systematic review studying the effects of a low-carbohydrate diet LCD on weight loss and cardiovascular risk factors showed that the diet that was studied was associated with significant decreases in body weight, body mass index , abdominal circumference, blood pressure , triglycerides , fasting blood sugar , blood insulin and plasma C-reactive protein , as well as an increase in high-density lipoprotein cholesterol HDL.
Low-density lipoprotein cholesterol LDL and creatinine did not change significantly. The study found the LCD was shown to have favorable effects on body weight and major cardiovascular risk factors but concluded the effects on long-term health are unknown.
The study did not compare health benefits of LCD to low-fat diets. A meta-analysis published in the American Journal of Clinical Nutrition in compared low-carbohydrate, Mediterranean, vegan, vegetarian, low-glycemic index, high-fiber, and high-protein diets with control diets.
The researchers concluded that low-carbohydrate, Mediterranean, low-glycemic index, and high-protein diets are effective in improving markers of risk for cardiovascular disease and diabetes. Advocates of low-carbohydrate diets generally dispute any suggestion that such diets cause weakness or exhaustion except in the first few weeks as the body adjusts , and indeed most highly recommend exercise as part of a healthy lifestyle.
Some critics imply or explicitly argue that vegetables and fruits are inherently all heavily concentrated sources of carbohydrates so much so that some sources treat the words 'vegetable' and 'carbohydrate' as synonymous. Thus, in absolute terms, even sweet fruits and berries do not represent a significant source of carbohydrates in their natural form, and also typically contain a good deal of fiber which attenuates the absorption of sugar in the gut.
Most vegetables are low- or moderate-carbohydrate foods in the context of these diets, fiber is excluded because it is not a nutritive carbohydrate. Some vegetables, such as potatoes , have high concentrations of starch, as do maize and rice. Most low-carbohydrate diet plans accommodate vegetables such as broccoli , spinach , cauliflower , and peppers.
Nevertheless, debate remains as to whether restricting even just high-carbohydrate fruits, vegetables, and grains is truly healthy. Contrary to the recommendations of most low-carbohydrate diet guides, some individuals may choose to avoid vegetables altogether to minimize carbohydrate intake. Low-carbohydrate vegetarianism is also practiced. Raw fruits and vegetables are packed with an array of other protective chemicals, such as vitamins, flavonoids , and sugar alcohols.
Some of those molecules help safeguard against the over-absorption of sugars in the human digestive system. Some evidence indicates the increasingly large percentage of calories consumed as refined carbohydrates is positively correlated with the increased incidence of metabolic disorders such as type 2 diabetes.
Some evidence indicates the human brain — the largest consumer of glucose in the body — can operate more efficiently on ketone bodies. In , the Canadian government ruled that foods sold in Canada could not be marketed with reduced or eliminated carbohydrate content as a selling point, because reduced carbohydrate content was not determined to be a health benefit.
The government ruled that existing "low carb" and "no carb" packaging would have to be phased out by In , John Rollo reported on the results of treating two diabetic Army officers with a low-carbohydrate diet and medications. A very low-carbohydrate, ketogenic diet was the standard treatment for diabetes throughout the nineteenth century. In , William Banting , a formerly obese English undertaker and coffin maker, published "Letter on Corpulence Addressed to the Public", in which he described a diet for weight control giving up bread , butter , milk , sugar , beer , and potatoes.
In the early s Frederick Madison Allen developed a highly restrictive short term regime which was described by Walter R. The process was halted if sugar appeared in the person's urine. In , Richard Mackarness M. Mackarness also challenged the "calorie theory" and referenced primitive diets such as the Inuit as examples of healthy diets with a low-carbohydrate and high-fat composition. The "Stillman diet" is a high-protein , low-carbohydrate, and low-fat diet.
It is regarded as one of the first low-carbohydrate diets to become popular in the United States. In , Robert Atkins published Dr. Atkins Diet Revolution , which advocated the low-carbohydrate diet he had successfully used in treating patients in the s having developed the diet from a article published in JAMA. The concept of the glycemic index was developed in by David Jenkins to account for variances in speed of digestion of different types of carbohydrates.
In the s, Atkins published an update from his book, Dr. Atkins New Diet Revolution , and other doctors began to publish books based on the same principles. This has been said to be the beginning of what the mass media call the "low carb craze" in the United States. In the United States, the diet has continued to garner attention in the medical and nutritional science communities, and also has inspired a number of hybrid diets that include traditional calorie-counting and exercise regimens.
From Wikipedia, the free encyclopedia. This is the latest accepted revision , reviewed on 12 September Not to be confused with slow carb diet.
This article is about low-carbohydrate diets as a lifestyle choice or for weight loss. For low-carbohydrate dietary therapy for epilepsy, see Ketogenic diet. This article has multiple issues. Please help improve it or discuss these issues on the talk page. Learn how and when to remove these template messages. This article needs more medical references for verification or relies too heavily on primary sources. Please review the contents of the article and add the appropriate references if you can.
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First, exercise stimulates enzymes that help move LDL from the blood and blood-vessel walls to the liver. From there, the cholesterol is converted into bile for digestion or excreted. So the more you exercise, the more LDL your body expels. Second, exercise increases the size of the protein particles that carry cholesterol through the blood. The combination of protein particles and cholesterol are called "lipoproteins;" it's the LDLs that have been linked to heart disease.
Some of those particles are small and dense; some are big and fluffy. Exactly how much exercise is needed to lower cholesterol has been a matter of some debate. In general, most public health organizations recommend, at a minimum, 30 minutes per day of moderate to vigorous exercise , such as walking, jogging , biking, or gardening.
But a study by researchers at Duke University Medical Center found that more intense exercise is actually better than moderate exercise for lowering cholesterol.
In a study of overweight , sedentary people who did not change their diet, the researchers found that those who got moderate exercise the equivalent of 12 miles of walking or jogging per week did lower their LDL level somewhat. But the people who did more vigorous exercise the equivalent of 20 miles of jogging a week lowered it even more. The people who exercised vigorously also raised their levels of high-density lipoprotein HDL -- the "good" kind of lipoprotein that actually helps clear cholesterol from the blood.
According to Kraus's findings, however, even though moderate exercise was not as effective in reducing LDL or increasing HDL, it did keep cholesterol levels from rising.
Just how much of an effect exercise has on cholesterol is also a matter of debate. If you haven't been exercising regularly already, it's important to start slowly. Be sure to check in with your doctor, so that he or she can evaluate your current cardiovascular health. This could mean blood tests or a treadmill test to see how your heart reacts when you exercise. Of course, exercise alone won't guarantee a low cholesterol level.
Genetics, weight, age, gender, and diet all contribute to an individual's cholesterol profile. The most effective way to ensure a healthy cholesterol level is to modify your diet and, if need be, take cholesterol-lowering medications.
But exercise has many advantages beyond lowering cholesterol. Exercise has been shown to keep bones strong, reduce the risk of cancer , diabetes , stroke , and obesity, and to improve mood.