Nutrition
Nutrition is a science that examines the relationship between health and diet. There are literally hundreds of books dedicated to the topics of nutrition and weight control. The following will provide you with some guidelines for healthy eating, while participating in an active lifestyle.
Macronutrients
Macronutrients are nutrients that the body uses in relatively large amounts. They provide calories to the body as well as performing other core functions. Macronutrients are the main components of food that the body needs on a chemical level. There are five macronutrients:
- carbohydrates
- proteins
- fats
- vitamins and minerals
- water
There is no magic involved or one diet that everyone can follow that guarantees optimal energy and a trim waistline. As individuals, we have different energy requirements based on our activity level, body composition, body size and genetics. The fact that food is energy is, however, one thing common to all individuals. There are three main sources of energy - carbohydrates, proteins and fats. Healthy eating requires that we take in adequate amounts of all of these energy sources.
Carbohydrates
Carbohydrates are the best source of energy, ideally making up 55 - 65% of your total energy intake. Nutritionists break down carbohydrates into two categories: simple and complex. Simple carbs,also known as simple sugars, are found in foods made from refined sugar, but also in nutritious foods such as milk and fruits. Complex carbs,also called starches, are found in grain products, such as bread, pasta, and rice.
When eating carbohydrates, the body breaks them down into glucose which is absorbed into the bloodstream. As sugar levels rise, insulin is released and movesthe sugar from the blood and into the cells where it can be used as energy or stored as glycogen. With simple sugars, this process happens quickly, so you’re likely to feel hungry again sooner. Consuming large quantities of simple sugars can give you a “sugar high” followed immediately by a “sugar low” or “crash”. The high can provide quick energy, but the low is associated with feelings of lethargy and sometimes nausea. Eating complex carbs, sugar absorption is slower and steadier and you feel satisfied longer. Complex carbs give you energy over a longer period of time. As with both simple and complex carbs, unrefined or whole foods are always a better choice.
If the sugar absorption rate is a medical concern for you, ask your doctor or nutritionist to show you how to check the Glycemic Index of food. This is a scientific scale of food absorption rates. You can then choose your foods,dependent on your medical situation,with a Glycemic Index.
Fats
It's important to have some fat in our diet because fat helps the body absorb vitamins, is a good source of energy and a source of essential fatty acids that our bodies can't produce. We cannot live without a certain amount of fat, yet its main function is to be stored. So consuming too much means we run the risk of weight gain. Unlike our remote ancestors, our body’s storage needs have significantly diminished once “hunting” for our next meal was no longer a necessity. Therefore, our fat consumption should only account for 30% of our energy intake.
We also need to think about the types of fat we eat. The primary dietary fats are “saturated” and “unsaturated”. The main sources of saturated fat are from animal products: red meat and whole-milk dairy products, including cheese, sour cream, ice cream and butter. But they are also found in some plant-based sources such as coconut and palm oils. In many cases, these fats are visible because they are solid at room temperature.
Unsaturated fats include “monounsaturated” and “polyunsaturated”. Both are derived from vegetables and plants. Monounsaturated fats are found in olives and nuts, canola, olive and peanut oils and avocados. Polyunsaturated fatsare found in sources such as corn, safflower and sunflower oils, as well as in certain types of fish such as tuna, salmon and sardines.
Cholesterol is another fatty substance found in our blood stream and cells. Often feared because of its links to cardio-vascular disease, a small amount of cholesterol is essential to many functions in the body. Cholesterol is produced by the body, as well as obtained through diet. Foods high in saturated fat generally contain substantial amounts of dietary cholesterol and in turn may raise cholesterol levels.
Proteins
Proteins are complex substances found in many foods and are made up of small units called amino acids. They are essential building blocks of the body and there are 21 different amino acids that make up proteins important for growth, regeneration, tissue repair and replacement. The amino acids that the body can produce are known as “nonessential”. The others, known as “essential” amino acids, must be provided through diet.
Proteins containing all the essential amino acids are known as “complete” proteins. Animal products such as meat, eggs and milk products are great sources of complete proteins. However, they also tend to be higher in saturated fat and cholesterol and should be consumed in moderation. By choosing lean cuts of meat and low fat dairy products, they can become a valuable part of a healthy diet.
In contrast, proteins missing one or more essential amino acids are called "incomplete proteins". In fact, no single plant contains all the amino acids the body needs; however, it is possible to obtain all the necessary amino acids from a vegetarian diet, provided a good variety of grains, cereals, legumes and vegetables are eaten.
If a diet is too low in calories from all food sources, the body will begin to use proteins as an energy source. It will take the protein in our muscles and convert it into calories. This is not healthybecause important muscle mass can be lost and our bodies in turn become weaker and flabbier. People who are dieting and severely restricting their calorie intake run this risk.
In most North American diets, a lack of protein is rarely a concern. Too much protein, however, can cause liver and kidney problems as these waste-removing organs become overloaded and have difficulty coping. Furthermore, if the main sources of protein are meat and dairy products, which can also contain a lot of saturated fat, there is a danger that blood cholesterol levels may increase.
Vitamins and Minerals
Vitamins and Minerals are essential elements that our bodies need in order to function properly.
Vitamins are natural substances found in plants and animals. Your body uses these substances to stay healthy and support its many functions, and vitamins play a key role in growth and cellular function. There are two types of vitamins: water-soluble (easily absorbed by the body) and fat-soluble (requiring bile acids to absorb into the body).
Vitamins cannot be made in adequate quantities by the body, so they must be provided by diet. Vitamin levels are normally self-regulating and there is generally no need to worry unless you experience specific symptoms of a deficiency (too little) or toxicity (too much) of a particular vitamin.
Minerals come from the earth or from water and plants and animals absorb them to get nutrients. Minerals are important for cell function and provide materials for structures like bones and teeth. The major minerals active people in their diet are iron (a component of hemoglobin, the oxygen transporter in the blood) and calcium (important in the maintenance of bone tissue and the prevention of conditions associated with bone tissue loss).
The market is full of nutritional supplements promising vitamins and minerals to enhance your lifestyle. It’s easy to be confused by the amount of information available. One recommended source is Canada’s Food Guide which recommends a balanced diet to provide a healthy person with all the necessary food intake requirements, including vitamins and minerals. Beyond that, consider supplementation to be a medical matter and not an aid to your training.
Deficiencies can sometimes arise for different reasons. Your doctor can identify any concerns specific to you and a nutritionist will help you to solve the problem. General supplementation is not likely to do anything for you which a healthy balanced diet cannot do; except lighten your wallet.
Physical Activity and the Vegetarian
It is, of course, possible to be physically active without eating meat. However, vegetarians shouldbe aware of the factors in the diet which must be addressed in order to accommodate activity. When in doubt, check with a nutritionist, who will assess your particular situation. The more you are committed to complete vegetarianism, the greater your need for attention to your food intake.
As described in the section on proteins, reduced intake of meat means a reduced intake of the amino acids that build various kinds of proteins in our bodies. Meat and dairy products contain all the essential amino acids, as do soy products. Proteins in other vegetables and legumes are incomplete because only some amino acids are present in low levels. As noted earlier, incomplete proteins can be combined to provide all the required amino acids, but it’s important that you know the combinations.
Vegetarians must eat protein foods that have complementary amino acid levels so that the essential amino acids missing from one protein food can be supplied by another. It was once believed that complementary proteins had to be consumed at every meal; however, intentional combining at each meal has been proven not necessary, as long as you eat a variety of plant foods, such as brown rice, corn, nuts, seeds, whole grains, and wheat within each 24 hour period.
A reduced intake of meat, especially red meat, can mean that your iron intake is lower than your requirements. Iron is a vital component in the production of aerobic energy. Since the iron in vegetables, even green leafy vegetables, is not easily absorbed, you will need to research and know where your iron supply is coming from when following a vegetarian lifestyle.
Weight Control
Maintenance of body weight: Energy input = Energy output
As calories are the energy in food, your body has a constant demand for energy and uses the calories to keep you functioning. Energy from calories fuels your every action. As proteins, fats and carbohydrates are the nutrients that contain calories, they are also the main energy sources for your body. Regardless of where they come from, the calories you eat are either converted to physical energy or stored within your body as fat.
It comes down to simple math: If you take in 2000 calories a day and burn 2000 calories a day, you will maintain your body weight. If you take in 2500 calories and only burn 2000, those additional 500 calories will be stored.
Unless you use these stored calories — either by reducing your caloric intake so that your body must draw on reserves for energy, or by increasing physical activity so that you burn more calories — this fat remains stored in your body. A sedentary individual would most likely store their excess calories in the form of fat. Yet storage can also be gains in muscle mass. For those that make weight training a regular part of their activity regimen, you can gain muscle mass during times when your energy intake surpasses your requirement.
On the energy deficit side, the relationship is not quite as simple. Generally, i,ecreasing calories in an attempt to loose weightf you consume 2000 calories and burn 2200 calories, this will result in a decrease in mass. But because our bodies have a powerful survival instinct, lack of energy does not always equate to weight loss. When where we are not taking in appropriate amounts of food energy, our bodies adapt by slowing down our metabolism. This adjustment in metabolism is designed to prevent large and fast losses in body mass that could pose a threat to the body’s vital systems.
To loose or gain weight, the energy balance equation works best when adjustments are small. For example, energy deficits should be no greater than 500 calories per day. Generally we count 3500 calories in one pound of body weight (body fat). A caloric deficit of 500 calories per day would result in a caloric loss for a week of 3500 calories or about 1 pound. A deficit greater than 500 calories per day may result in metabolic adjustments and a loss in muscle rather than fat. On the other hand, if gains in energy exceed 500 calories per day, you run the risk of gaining fat and not muscle.
Vegetarians seeking weight loss should also be aware that their diet may not automatically produce the desired results. Active people are hungry people. A vegetarian’s intake of calories may actually be too high from an over consumption of rice, granola and pasta. Some ‘so-called’ protein replacements also have a high-fat content (cheese, beans, nuts). Remember, fat’s main job is to be stored!
Fundamentally, for optimal training and performance you cannot compromise energy. It is virtually impossible to train and perform at your best if decreasing calories in an attempt to loose weight. Eating a balanced diet, high in carbohydrates and low in fat, will ensure that you have the energy to maintain your active lifestyle.
Hydration & Water —
The most important and often neglected nutrient!
Our bodies need six nutrients to function properly: carbohydrates, proteins, fats, minerals, vitamins and water.
Over 60% of our body is comprised of water and our need for water increases greatly with exercise. Muscle tissue alone is over 70% water and vital body functions can be seriously compromised when an individual is dehydrated. A constant supply is required as all bodily functions depend on the balance of body water.
Athletes lose more contests through not drinking enough water than from any other nutritional cause! Adequate fluid intake before, during and following exercise is critical in preventing dehydration. Thirst is not the best gauge of your body’s water needs.
A common reaction to drinking water is to wait until you are thirsty. This is a significant mistake as the body is already dehydrated by the time thirst is apparent. Dehydration is defined as the loss of fluid from all of the body's fluid compartments. It occurs when the rate of fluid lost is greater than the rate of fluid replaced. Loss is at its greatest during activity.
Almost any drink which you find appetizing, even carbonated, can re-hydrate you, even if not the best choice. Exceptions are drinks containing alcohol or caffeine. These beverages will actually cause more rapid fluid loss due to the diuretic effect, and even though you may feel that you are getting replenished from these types of liquids, you are really losing it nearly as quickly as you drink it.
Remember, for proper hydration...
- Keep weather conditions, body size, and metabolism in mind when determining how much water to consume. These all affect water loss.
- For exercise lasting less than 3 hours, water is the best replacement.
- For intense exercise lasting greater than 3 hours, diluted glucose and electrolyte solutions are recommended to provide fuel for working muscles.
- Modern sport drinks contain fluids necessary for replacement. Many athletes find them appetizing and refreshing; however the nutrient value can be generally less than that of fruit juices and solid replacement foods. Opting for sports drinks is a matter of personal taste and preference.
- Drinks containing more than 10% carbohydrates may inhibit fluid replacement and cause nausea, diarrhea and cramps. If your drink tastes too strong, dilute it with water or considerother options like plain water and fruit.
- Regardless of outside temperatures, fluids are important throughout all seasons (summer & winter).
Fluid Intake Schedule:
2 cups2 hours before exercising
1 – 2 cups10 – 1 min. before exercising
1/3 – 1 cup15 – 20 min. intervals during exercise
about 1 cup10 – 15 min. after exercising
Hydration is vital and everybody engaging in exercise, at all levels and intensities, should work to increase their water intake.
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