Posts Tagged ‘Fat’
The Health Effects of Fiber
The Health Effects of Fiber
Fiber is hardly the cure-all some have suggested. But neither does fiber belong at the bottom of the nutritional totem pole, where it resided for more than a century as a nonessential dietary ingredient. There is good evidence, for example, that certain dietary fibers can lower blood cholesterol levels and improve the processing of blood sugar by diabetics.
Although the evidence is conflicting, high-fiber diets have been helpful to many patients with chronic intestinal disorders, such as constipation, spastic colon, diverticular disease, and even Crohn’s disease (regional enteritis or ileitis). And there is some evidence that fiber can help to lower blood pressure and ward off gallstones.
What Is Fiber?
What Is Fiber?
Dietary fibers come only from plants. They are the chemical substances in the cell walls that give plants structure and stability. Fibers in elude cellulose, polysaccharides, hemicelluloses, pectins, gums, mucilages, and lignin.
Different kinds of plants contain different fibers. Even within a species, the fiber content may vary according to growing conditions and maturity at harvest. Bran is almost entirely cellulose; apples, grapes, and some other fruits are high in pectin.
Fibers are not digested by human digestive enzymes. However, many are partially or completely digested by bacteria that reside in the gut, resulting in the production of gases.
Sugar : Too Much of a Bad Thing
Sugar : Too Much of a Bad Thing
Sugar proponents call it quick energy, opponents say it’s empty calories. To the average American, who consumes a third of a pound of it each day, sugar is mostly an irresistibly good taste. Human societies have long equated sweetness with goodness – sweet mystery of life, sweet smell of success, sweetheart – and that enhances the attraction.
People seem to have an innate “sweet tooth.” If saccharin is injected into the womb, the fetus will increase its swallowing of the sweetened amniotic fluid. Newborn rats given a choice will consume sugar water in preference to a nutritious diet, even to the point of malnutrition and death.
A Simple Guide to Complex Carbohydrates
A Simple Guide to Complex Carbohydrates
Here is a dietary guide to the good carbohydrates.
Potatoes. As they come from the ground, potatoes are relatively low in calories (150 for a large baking potato) and high in nutrients, including some protein. An adult could derive nearly all needed nutrients from potatoes. Baked, steamed, or boiled, they are an excellent food. But a single pat of butter or margarine increases the calorie content of a medium-sized potato by a third.
Deep-frying destroys some vitamins and adds astronomically to calories. Of the calories in french fries, 70 percent are from fat. Potato chips are also mostly fat (and high in salt) – 150 calories per ounce, 90 of them from fat. About nine chips add up to 100 calories.
The Body’s Main Fuel
The Body’s Main Fuel
Carbohydrates, both simple and complex, are the body’s main source of energy. They are readily digested and converted into the blood sugar glucose, which fuels the brain and muscles. Without carbohydrates, the body must rely on fats and protein for energy. Fats bum inefficiently in the absence of carbohydrates and leave the kidneys with the burden of excreting large amounts of toxic metabolic chemicals called ketone bodies. These can build up in the blood and cause nausea, fatigue, and apathy, a common effect among those who adhere to the faddish lowcarbohydrate diets.
When protein is used for energy, the body is deprived of this crucial nutrient for building and replacing tissues, and the kidneys have to get rid of the unused nitrogen that’s left over. That’s why on high-protein diets you must drink lots of water to help flush out your kidneys.
Starches: Not Fattening and Good for You
Starches: Not Fattening and Good for You
There’s one simple way to save calories and money in your daily food budget: Eat the potatoes. Also the rice, pasta, corn, beans, and bread. Strange advice, coming in a book on healthful living? Aren’t these the starchy foods, high in calories and low in nutrients, that our forefathers were forced to live on but that we, in our late-twentieth-century affluence and abundance, can afford to pass up or merely sample now and again?
The answer is yes – and no. Yes, these are starchy foods, laden with so-called complex carbohydrates (as opposed to sugars, which are simple carbohydrates). No, they are not high in calories. Ounce for ounce, they have no more calories than pure protein, and they have fewer than half the calories in fat.
The Evidence Against Cholesterol
The Evidence Against Cholesterol
The following kinds of studies have linked dietary fats and cholesterol to coronary deaths:
Biochemical. Cholesterol and substances made from cholesterol are the primary constituents of deposits that clog arteries, producing atherosclerosis, the main cause of deaths from heart disease. Cholesterol consumed as part of the diet has been shown to wind up in these deposits, rendering it guilty by association but not proving its harmful role beyond a reasonable doubt.
Epidemiological. Of seventeen major studies among peoples in various parts of the world, fourteen showed a very strong relationship between the average blood cholesterol level and the incidence of heart disease and coronary deaths. In the famous Framingham Heart Study, elevated blood cholesterol was singled out as one of three major risk factors for coronary heart disease.
The Cholesterol Controversy
The Cholesterol Controversy
Probably no other aspect of nutrition confuses people more than cholesterol, a waxy alcohol found only in animal foods that has long been labeled a primary culprit – along with its usual companion, saturated fats – in the national epidemic of heart disease.
Every other week, it seems, conflicting evidence is reported that alternately blames and absolves cholesterol and the foods, such as eggs, in which it is most prominent. In 1980 the prestigious Food and Nutrition Board of the National Academy of Sciences, which sets the nutritional standards for normal Americans, contradicted the advice of twenty other organizations concerned with public health by stating that healthy people need not restrict dietary cholesterol and saturated fats since such a cutback has not been proved to have lifesaving benefits.
Cutting Down on Hidden Fat
Cutting Down on Hidden Fat
Most of the fat in our diets is hidden fat. It is the hard-to-notice marbling in meat. It is an integral part of hard cheeses and cream cheese, fish, deep-fried foods, nuts, seeds, cream soups, ice cream, and chocolate. It is a major ingredient in a wide variety of factory-prepared products, including baked goods (especially cakes, pies and cookies), processed meats (frankfurters, bologna, and the like), instant meals, coffee whiteners, whipped toppings, snack foods, and granolas. Even one popular diet product, Pillsbury’s Figurines, has fat as its main ingredient.
Yet those who advocate more healthful diets that are not overly dependent on red meat often substitute fattier foods than the ones they reject. Examples include the quiches, avocado salads, nuts and seeds, nut butters, sesame paste, and granolas featured in health food restaurants and stores. A quiche is made from cheese in which three-fourths of the calories come from fat that is more saturated than meat fat, cream in which nearly all the calories are fat, and piecrust in which more than half the calories are fat calories.