Friday, January 31, 2014

Basic Nutrition by Theodore C. Friedman, M.D., Ph.D. and Winnie Yu

Eating well is one of the cornerstones of good health. But unfortunately, most American diets these days are far from optimal. Most are laden with high-fat convenience foods, excess sugar, and too many calories from large portions. To make matters worse, mealtimes for many people have become erratic and irregular, with too many meals eaten on the run.
The truth is, the foods you choose and the way you eat can make a huge difference in your health. On a day-to-day basis, they can affect the way you feel, how well you sleep, and how energetic you are. Over time, they can influence your likelihood to become overweight or obese, and your vulnerability to serious diseases. To help you make smarter choices, it helps to have a general understanding of basic nutrition.

Carbohydrates

Low-carb. High-carb. You hear a lot about carbohydrates these days. Carbohydrates are your body's primary source of energy and come in two forms: simple and complex. Simple carbs are those found naturally in fruits, vegetables, and milk as well as foods that contain refined sugars, which have been processed to extract the natural sucrose found in plants for a sweeter flavor.
Simple carbs break down rapidly, giving you a quick burst of energy. Healthy simple carbs include fruits, vegetables, and low-fat dairy products. Unhealthy simple carbs include cakes, cookies, crackers, sugary cereals, and snack foods. Rice, potatoes, and corn are also simple carbs that some recommend avoiding.
Complex carbohydrates are considered the healthier carbs, and are made up of starches and fiber found naturally in legumes, grains, and vegetables. Starch is found in the storage systems of plants such as wheat, oats, potatoes, beans, and lentils. In the body, starches break down into simple sugars, but do so more slowly than the simple carbs do.
Fiber, however, cannot be digested in the stomach and converted into simple sugars. That's because humans lack the enzyme required to break it down. Instead of being taken up by your body for energy, fiber is excreted, a fact that has made it a powerhouse in treating and relieving digestive disorders. A more lengthy discussion on fiber appears later in this chapter.
To maximize your health, eat a moderate amount of complex carbs, which will help keep cholesterol levels down and minimize weight gain. Limit simple carbs to fruits and vegetables, which supply other healthy nutrients. Try to cut back on your intake of carbs composed primarily of refined sugars. These include cakes, cookies, crackers, candy, ice cream, potato chips, sweetened sugars and juices, and most snack foods. Some people, like Dr. Friedman, believe in and practice a low-carbohydrate diet. He completely avoids all unhealthy simple carbs and also minimizes complex carbs. You should talk to your doctor about the best foods for you.

Protein

Foods rich in protein supply the body with the amino acids needed to build, repair, and maintain body tissues. When your body doesn't get enough carbohydrates or fats, it turns to protein for energy. Protein is found in meat, eggs, legumes, seeds, nuts, soybeans, and tofu. Getting enough protein, which is generally not a problem in the American diet, ensures healthy muscle and tissues.

Fact

Although protein has long been associated with muscle-building, it really doesn't build muscle strength or size by itself. Only by combining protein with strength training can there be any muscle building. But remember, any excess protein you eat is stored as fat and not burned as energy.
One of the best things about protein is that it helps you feel full, so that you are less likely to overeat. In people with hypo- or hyperthyroidism who have an increased appetite, protein may help calm the urge to eat and minimize any excess weight gain.

Fats

Fats have been demonized for our nation's weight problems. But in reality, fat is an essential nutrient, vital to the brain and nervous system. It is also the substance that lends cheesecake its smooth, creamy texture and makes macaroni and cheese so rich and tasty.
The problem with fat is its high caloric density. Unlike carbohydrates and protein, which supply four calories per gram, fat delivers a whopping nine calories per gram, making it the most concentrated form of energy. Fat comes in four basic forms:

Monounsaturated Fats

Monounsaturated fats that occur naturally in avocados and olive oil are the healthiest fats.

Unsaturated Fats

Polyunsaturated fats are liquids found in vegetable oils such as safflower, sunflower, and corn and are not as healthy as monounsaturated fats. However, omega-3 fatty acids found in fish are a healthy form of polyunsaturated fat.

Saturated Fats

These are the unhealthy fats that clog arteries and raise the risk of heart disease. These are solid at room temperature and come from meat, whole dairy foods, butter, and palm and coconut oils.

Trans-Fatty Acids

These fats are not found in nature, but rather are produced when oils are hydrogenated to make them solid at room temperature. These are found in all processed foods, such as breakfast cereals, frozen pancakes, potato chips, crackers, and cookies. They're also found in margarine and shortening.
The problem with fat occurs when you eat too much of it. The dense calories make it a fast and surefire way to gain weight. And too much of the unhealthy forms of fat can lead to health problems such as heart disease, diabetes, and certain cancers.

Vitamins and Minerals

Mother always said to take your vitamins, and she was right — vitamins and minerals supply the body with important substances that maximize our health and body functions. While vitamins and minerals do not supply the body with energy, they do help facilitate reactions that produce energy from the foods you eat.

Vitamin A, for instance, guards against infections, while vitamin D helps strengthen bones. And we already know that iodine, a mineral, is essential to the production of thyroid hormone.

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