While dieting is often thought of as a way to lose weight, the pursuit of a svelte body isn't the main goal of all diets. Some are simple modifications aimed at improving blood pressure and better overall health.
Here are five diets that can help fend off diseases and make you healthier.
Low-glycemic index diet
The glycemic index diet is based on the idea that carbohydrates that can lead to a rapid increase in blood sugar levels should be avoided.
The diet focuses on consuming the "right" carbohydrates to keep your blood sugar balanced.
Foods that are emphasized include low-glycemic index breads such as pumpernickel and rye, large flake oatmeal, oat bran, pasta, parboiled rice, quinoa, beans, peas, lentils and nuts. People are also encouraged to eat plenty of fruits and vegetables, and few potatoes.
Although a diet of low-glycemic index foods is the basis of weight loss plans such as Nutrisystem and the Zone diet, the diet has a more significant impact on patients with Type 2 diabetes, or prediabetes. Not only can the diet help control blood sugar levels and reduce overall diabetes risk, it can also increase high-density lipoprotein (the "good" cholesterol) and reduce overall cardiovascular risks.
In a randomized clinical trial published in the Journal of the American Medical Association in 2008 in which 210 people followed the diet for six months, the diet was shown to be more effective at controlling blood sugar levels than a high-cereal fiber diet consisting of "brown" carbohydrates such as whole grain breads, whole grain breakfast cereals, brown rice, potatoes with skins and whole wheat bread.
Though a vegetarian diet may be adopted for cultural, religious or ecological reasons, a primarily plant-based diet also brings health benefits. According to the American Heart Association, studies have shown that vegetarians seem to have a lower risk of obesity, coronary heart disease, high blood pressure and diabetes.
Most vegetarian diets, even ones that include eggs and dairy products, often have less saturated fat and cholesterol and more complex carbohydrates, dietary fiber, magnesium, folic acid, vitamin C and E and carotenoids than diets that include meat.
Concerns that a vegetarian diet lacks protein and essential vitamins can be addressed though careful meal planning and a balanced diet, according to the National Institutes of Health.
"DASH," which stands for "dietary approaches to stop hypertension," is a diet promoted by the National Heart Lung and Blood Institute as a way to lower blood pressure. Much of the eating plan is rather intuitive it stresses a balanced meal rich in fruits, vegetables, fat-free or low-fat dairy products, whole grains, fish, poultry, beans, seeds and nuts. It also contains less sodium, sugar, fats and red meats than the typical American diet.
There are no special recipes; however, the daily caloric intake and the number of allowable servings should correspond to a person's age and level of physical activity.
The blood pressure reduction can happen quickly, as early as two weeks into the diet. A recent randomized study by Duke University researchers in 2010 involving 144 overweight, unmedicated patients showed that the diet alone could reduce systolic blood pressure (the top blood pressure number) by 11 points and diastolic blood pressure by 7 points.
And the DASH diet, in combination with exercise, can reduce systolic blood pressure by 16 points and diastolic blood pressure by 10 points, the study showed.
The same study also shows that, aside from lowering blood pressure, the DASH diet, combined with exercise and weight loss, can offer significant improvements in insulin sensitivity for overweight and obese individuals. Another 2010 study by Johns Hopkins University researchers showed that the diet can also trim the estimated 10-year coronary heart disease risk by 18 percent for individuals with prehypertension or stage-1 hypertension.
Low-gluten diet or gluten-free diet
Gluten is a type of protein found in grains like wheat, barley and rye. Diets that limit or eliminate gluten are often prescribed to patients with celiac disease, in which the immune system responds to gluten by irritating and damaging the small intestine. This prevents the body from absorbing such important nutrients as vitamins, calcium, protein, carbohydrates and fats.
Aside from avoiding wheat, barley and rye, people who follow a gluten-free diet will also have to omit many breads, pastas, cereals and processed foods from their diet.
Although there are anecdotal claims that a gluten-free diet can lead to behavioral improvements for people with autism, so far there is no evidence-based research that supports these claims. A 2010 consensus report published in the journal Pediatrics by Harvard Medical School researchers explained that while gastrointestinal disorders and associated symptoms are reported in autistic individuals, a link between autism and gluten in the diet has not been established.
While more research is on the way, currently there are no studies showing that a gluten-free diet affects any health conditions other than celiac disease.
The Ketogenic diet is not for everybody. In fact, this highly specialized and carefully balanced diet is meant for people with epilepsy (especially children) whose seizures have not responded to medicines.
Those on the diet adhere to a very specific ratio of fat, carbohydrate and protein: around 80 percent fat, 15 percent protein and 5 percent carbohydrate.
Meal plans are patient-tailored and can include heavy cream, bacon, eggs, tuna, shrimp, vegetables, mayonnaise, sausages and other high-fat and low-carbohydrate foods. Patients should not eat starchy vegetables and fruits, breads, pasta or sources of simple sugars (even toothpaste might have some sugar in it). Side effects, according to the Mayo Clinic, include constipation, dehydration, lack of energy and hunger.
The diet, though unconventional, is effective at controlling epilepsy. One clinical trial published in The Lancet in 2008 showed that children on the ketogenic diet reduced the number of seizures they suffered by more than a third, compared with children not on the diet.
On top of that, 28 out of 54 children on the diet suffered 50 percent fewer seizures, and five children had better than 90 percent seizure reduction after staying on the diet for three months, the study showed.
However, the diet's strictness, unpalatability and side effects can make it difficult to adhere to.
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