Understanding the Basics of Nutrition by Alice Koh To lose or maintain your weight, to rehabilitate your injuries, to build muscles or to improve health, you need to know about your calorie intake, your diet and the nutritional values of what you eat. Everybody is different and there is no one-size-fit-all kind of diet. Besides physiological differences, genes do play a part in determining one's body composition especially body fat. There is a minimum caloric value we have to adhere in order to keep our body functioning. This is called the Resting Metabolic Rate (RMR). This is the energy you burn at rest. You can calculate your RMR by multiplying your weight by 0.9 calories (for women) or (1 for man) x 24 (the hours a day). For example, a woman who weighs 68 kg will have a RMR of 1469 (68 × 0.9 x 24). This means that with no physical activities, she needs 1469 calories daily just to sustain her life. If she eats less than this value, her health will be adversely affected. If her physical activities are considered moderate, her total daily energy expenditure could go up as high as 2585. If she consumes less than 2585, there will be a weight loss. If she consumes more, she will become fat. Even a fat-free food can have a lot of calories. Excess calories in any form can be stored as body fat. Be aware when you see labels like "calorie-free". It doesn't mean it contains zero calories but actually it contains less than 5 calories per serving. “Sugar-free” and “fat-free” both mean less than 0.5 g (grams) per serving. Each gram of carbohydrate and protein yield 4 calories/gram. Each gram of fat yields 9 calories. Most people view fat negatively. However, fat serves a multitude of crucial body functions and also provide the material for hormone production, such as testosterone. Not all fats are bad. Good fats like monounsaturated and polyunsaturated fats are commonly found in plant-based sources such as avocados, nuts, seeds, canola and flaxseed oil. They are typically liquid at room temperature. They improve blood cholesterol levels, ease inflammation, stabilize heart rhythms, and play a number of other beneficial roles. Omega-3 and omega-6 are important types of polyunsaturated fats. They are essential for brain function. Salmon and mackerel are good source for these fatty acids. Animal sources of fat often contain higher amounts of saturated fats which are commonly known as bad fats. Saturated fats are typically solid at room temperature, therefore they are called “solid fats.” They are found mainly in meat and dairy food and they contribute to clogged arteries and cardiovascular diseases. It is recommended that 20-30% of one's total caloric consumption be derived from fat sources, with no more than 7-10% coming from saturated fat. Trans fats are found in two forms — natural, which occur in some animal products and aren’t considered harmful, and artificial which are hydrogenated vegetable oils and have serious health consequences. They are found in fast foods, boxed foods, baked goods and processed snacks. Trans fats have a profound effect on the blood lipid profile and health by increasing LDL cholesterol (or low-density lipoprotein: which is the bad cholesterol) and reducing HDL cholesterol (or high-density lipoproteins: which is the good cholesterol): which increases the risk for heart diseases. To avoid trans fats, it’s important to read labels carefully. Don’t buy products that have the label "hydrogenated" in them. Carbohydrates are one of three main nutrients found in foods and drinks, the other two are protein and fat. Carbohydrates are fuel for the brain and muscles. Depending on the intensity of your exercises, it is recommended that 50% and 70% of calories intake should come from carbohydrates. It is best that the surplus of energy for exercise should come from complex carbohydrates and natural simple sugars. Processed carbohydrates or simple carbs such as refined and processed sugars should be avoided. Simple carbohydrates are found naturally in foods such as fruits, milk and milk products. They are also found in processed and refined sugars such as candy, table sugar, syrups and soft drinks. They are absorbed quickly causing a spike in the sugar in your blood to provide short-lasting source of energy. However, this sugar rush comes down quickly too, leaving you tired, fatigued and hungry. The difference between the natural simple sugar found in a fruit and the refined sugar found in a soda-pop is that the fruit comes with vitamins, minerals, water and fiber. The sweetness is from fructose which does not cause a sharp insulin spike as opposed to sucrose and glucose which is found in soda. Not all complex carbohydrates are healthier choices. For example, breakfast cereals contain more than 42 percent refined sugar. Sugar is sugar no matter if it is called brown sugar, honey or corn syrup, maple syrup, maltodextrin, or sucrose. Not all simple carbohydrates are bad; milk and fruits are full of healthy nutrients. Therefore, it is essential that you always choose whole foods so that you can be assured of its nutritional value. USDA recommends 20 to 35 grams of fiber per day. Fiber comes from vegetables, fruits, oats, beans and legumes, peas, nuts and seeds. Fiber is important in weight loss diet as it suppresses appetite and increases fullness. There is little fiber in processed foods. To get the most fiber, eat the skin on vegetables and fruits and whole-grain flour-based products. Other benefits of fiber include healthy colon which will reduce the risk for colon cancer. It also plays a role in reducing cholesterol. Protein is an important part of a healthy diet. Proteins are made up of chemical "building blocks" called amino acids. Your body uses amino acids to build and repair muscles and bones and to make hormones and enzymes. They can also be used as an energy source. Meat, eggs, quinoa, oats and fish are a good source of protein. Sedentary adult is recommended to eat 0.4 grams per 1 pound of body weight. If you weigh 170 pounds, multiply 170 x 0.4 = 68 grams of protein a day. Active adults who exercise three times a week need around 0.5 to 0.75 grams of protein per pound of body weight. A competitive athlete may need as much as 0.9. Protein can be found in most meat and in plant sources such as dried peas and beans, lentils, soybeans and black beans. Dairy foods like cottage cheese and Greek yogurt are rich in protein. But how can you tell if you are getting your proteins, carbs, good fats and calories at the right amount? The Food Pyramid was created in 1992 by the United States Government to show the optimal servings from the different food groups to be eaten each day. The Food Pyramid is organised into four basic food groups which included meats, dairies, fruits, vegetables (cereals and grains). At the pyramid's base are the refined carbohydrates, the middle are the meat and milk, and the tip are the fats. This means that people should eat on a daily basis food such as pasta, bread, fruits and vegetables, and meat products should be eaten less often [https://www.health.harvard.edu/blog/crumbling-confusing-food-pyramid-replaced-by-a-plate-201106032767] In 1993, Oldways created the Mediterranean Diet Pyramid – in partnership with the Harvard School of Public Health and the WHO – as a healthier alternative to the USDA’s original food pyramid. The Mediterranean diet pyramid essentially reflects the eating habits of certain Greek and Italian populations around 1960, when their chronic disease rates were among the world’s lowest and adult life expectancy was the highest despite limited medical services. It recommends, among other things, wine in moderation and daily physical activity. The Mediterranean Diet Pyramid is associated with reduced risk of cardiovascular diseases. It is characterized by a high intake of olive oil, fruits, nuts, vegetables and cereals and moderate intake of fish and poultry. Legumes, which include chickpeas, lentils, garbanzo beans and soybeans are highly recommended. The diet is low to very low in dairy products, red meat, processed meat and sweets. You will also find an emphasis on activity and social connections. All pyramids recommend to drink lots of water. The human body is made up of 75 percent water. Water is necessary for blood flow and digestion of food. For workouts that last longer than about an hour, sports drinks are recommended. They provide the water fluid as well as electrolytes like potassium, magnesium, calcium and sodium that you lose as you sweat. However, natural water is best. To maintain a consistent energy level throughout the day and to prevent fainting episodes, make an effort to eat small, frequent meals. Eating irregular meals can lead to a higher risk of type 2 diabetes, high blood and obesity. It can also make you fatigued all the time, less focused, bad-tempered and irritable. [Please note, photo was taken from the following site: https://fruitsandveggies.org/stories/buzz-mediterranean-diet-reduces-risk-gerd/]