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| Food and nutrition |
 Fat |
| Perils of Trans-fats |
| Protein |
| Carbohydrates |
| Fiber |
| Vitamins and minerals |
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| Fat |
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What are fats?
Fats are heterogeneous group of compounds which are related more by their physical rather than by their chemical properties.
Why are fats important?
Fats are important dietary constituents because of their high-energy value and also because they deliver fat-soluble vitamins and essential fatty acids found in foods.
What are the right kinds of fats and why are they important?
Fats include fatty acids, triglycerides, cholesterols etc.
The good fats
Some fats are good because they can improve blood cholesterol levels.
Unsaturated fats - Polyunsaturated and Monounsaturated
Unsaturated fats are found in products derived from plant sources, such as vegetable oils, nuts, and seeds. There are two main categories: polyunsaturated fats (which are found in high concentrations in sunflower, corn, and soybean oils) and monounsaturated fats (which are found in high concentrations in canola, peanut, and olive oils). Studies in which polyunsaturated and monounsaturated fats were consumed in place of carbohydrates, the former decreased LDL levels and increased HDL levels.
What are the bad fats that one should avoid and why?
The bad fats
Some fats are bad because they tend to worsen blood cholesterol levels.
Saturated fats
Saturated fats are mainly animal fats. They are found in meat, seafood, whole-milk dairy products (cheese, milk and ice cream), poultry skin and egg yolks. Some plant foods are also high in saturated fats, including coconut and coconut oil, palm oil, and palm kernel oil. Saturated fats raise total blood cholesterol levels more than dietary cholesterol because they tend to boost both good HDL and bad LDL cholesterol. The net effect is negative, meaning it is important to limit saturated fats.
Trans fats
Trans fatty acids are fats produced by heating liquid vegetable oils in the presence of hydrogen. This process is known as hydrogenation. The more hydrogenated an oil is, the harder it will be at room temperature.
Trans fats are even worse for cholesterol levels than saturated fats because they raise bad LDL and lower good HDL cholesterol. While you should limit your intake of saturated fats, it is important to eliminate trans fats from partially hydrogenated oils from your diet.
Cholesterol
Cholesterol is present in all animal tissues and not in plants.
Cholesterol is not an essential nutrient. All of us are capable of synthesizing cholesterol. An average human makes about 75% of blood cholesterol in his or her liver, while only about 25% is absorbed from food. The biggest influence on blood cholesterol level is the mix of fats in the diet.
Cholesterol plays essential roles in the formation of cell membranes, some hormones, and vitamin D. Too much cholesterol in the blood, though, can lead to problems. Deposits of cholesterol can build up inside arteries. These deposits, called plaque, can narrow an artery enough to slow or block blood flow. This narrowing process, called atherosclerosis commonly occurs in arteries that nourish the heart (the coronary arteries). When one or more sections of heart muscle fail to get enough blood, and thus the oxygen and nutrients they need, the result may be chest pain known as angina. In addition, plaque can rupture causing blood clots that may lead to heart attack, stroke, or sudden death.
Cholesterol-carrying lipoproteins play central roles in the development of atherosclerotic plaque and cardiovascular disease. The two main types of lipoproteins basically work in opposite directions.
Low-density lipoproteins (LDL) carry cholesterol from the liver to the rest of the body. When there is too much LDL cholesterol in the blood, it may get deposited on the walls of the coronary arteries. Because of this, LDL cholesterol is often referred to as the "bad" cholesterol.
High-density lipoproteins (HDL) carry cholesterol from the blood back to the liver, which processes the cholesterol for elimination from the body. HDL makes it less likely that excess cholesterol in the blood will be deposited in the coronary arteries, which is why HDL cholesterol is often referred to as the "good" cholesterol.
In general, the higher your LDL and the lower your HDL, the greater your risk for atherosclerosis and heart diseases.
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| Perils of Trans-fats |
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Why worry about Trans-fats?
 | Studies done on trans-fat have raised concern for several decades that consumption of trans-fat might have contributed to the 20th century epidemic of Coronary Heart Disease (CHD) [2].
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| Researchers at the Harvard school of Public Health have found removing trans-fat from industrial food supply could prevent tens of thousands of hearth attacks and cardiac deaths each year.
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What are Trans-fats?
| Trans fats are solid fats produced artificially by heating vegetable oils in the presence of metal catalyst and hydrogen, in a process called Hydrogenation [2]
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| Major sources of trans-fat are partially and fully hydrogenated vegetable oils like vanaspati, shortening
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| These oils are usually used to make baked and fried foods such as samosas, puffs, cookies, crackers, cakes, pie, bread and other baked goods. It is also present in lower levels in margarine, potato chips, salad dressing cereals and candy.
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Why do people use trans-fats?
| Food manufacturers use partial hydrogenation of vegetable oil to destroy some fatty acids, such as linolenic and linoleic acid, which tend to oxidize, causing food to become rancid with time.[2]
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| Hydrogenation helps in increasing the shelf life and flavor stability of foods containing this fat. [1]
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| Commercial baked goods frequently include trans fat to prevent against spoilage.
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What are the health effects of using Trans-fat?
| Metabolic studies have shown that trans fats have adverse effects on biolipid levels – increasing LDL(Bad Cholesterol) while decreasing HDL(Good Cholesterol).
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| Trans fat have been associated with an increased risk of CHD in epidemiological studies,
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| Based on available metabolic studies, approximately 10,00 premature CHD deaths annually could be attributed to the consumption of trans fat
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| Trans fat increases the level of LP(a). High blood levels of LP(a) have been associated with an increased risk of CHD independently of LDL or HDL cholesterol concentration.
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Do all Fats need to be avoided?
| No. Fats are major source of energy for the body and aids in the absorption of vitamins A, D, E and K and carotenoids. Hence moderate intake of fats is very important for proper functioning of the body.
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| Replace trans-fats with unsaturated fats (monounsaturated and poly unsaturated), which don’t raise LDL levels and have health benefits when eaten in moderation. Sources for monounsaturated fats include olive and canola oils. Sources for polyunsaturated fats include soybean oil, corn oil, sunflower oil and food like nuts.
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| Saturated fats are essential in limited quantities. Use sources of saturated fats such as butter sparingly.
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How do I avoid trans-fats?
| The best alternatives to trans-fats containing oils is to replace them with healthier oils
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| Instead of using fats such as vanaspati and shortening, use vegetable oils rich in unsaturated fatty acids such as olive oil, sunflower oil, canola oil etc
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| Trans-fats are often unwittingly consumed when we indulge in convenience baked foods and breads. When you have the urge to snack, choose wisely. Snack on fruits and products that are cooked in healthier oils.
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Reference :
[1] http://www.fda.gov/fdac/features/2003/503_fats.html
[2] http://www.hsph.harvard.edu/reviews/transfats.html
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| Protein |
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What are proteins?
Proteins are the basis for the major structural components of animal and human tissues. Proteins are essential in everybody's diet. They are complex substances found in many foods and are made up of thousands of small units called amino acids. They contain about four calories per gram, but the body prefers to use carbohydrate and fat as energy sources.
Why are proteins important in my diet?
It is vital that we eat enough protein. Proteins are the building blocks of the body. The different amino acids that make up proteins are important for growth, tissue repair and replacement. Bones, muscles, the walls of hollow organs - in fact almost every part of the body - need a supply of amino acids in order to keep healthy.
How much protein do I need?
Experts recommend that each day we should eat roughly 0.75 grams of protein per kilogram of body weight. You can use the table below to act as a guide to your protein requirements.
| Weight in kilograms | Min recommended dailyintake of protein (grams) | | 51 | 40 | | 57 | 43 | | 63 | 48 | | 70 | 52 | | 76 | 57 | | 83 | 62 | | 89 | 67 |
From a kcalories point of view, about 15 per cent of your total daily kcalories should come from protein.
If our diet is too low in calories (from all food sources) the body will begin to use protein as an energy source. It will take the protein in our muscles to convert into calories. This is not good because when this happens important muscle mass is lost and our bodies become weaker and flabbier. People who are dieting and severely restricting their calorie intake run this risk.
Too much protein, however, should also be avoided as this can cause problems in people who have liver and kidney problems. These waste-removing organs become overloaded and have difficulty in coping with. 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 might increase.
What are the best sources of proteins?
Meat, egg and fish are excellent sources of protein. However, you can also get protein from cereals, dairy products, nuts, lentils, pulses and some vegetables.
The proteins in meat, egg and fish provide all the amino acids the body needs, and in approximately the right proportions. For this reason, they are called "complete proteins".
In contrast, the proteins from plants are called "incomplete proteins" because they do not contain all the amino acids the body needs. In fact, no single plant contains all the amino acids the body needs. However, it is possible to obtain these amino acids from a vegetarian diet, provided a good variety of grains, pulses, cereals and vegetables are consumed.
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| Carbohydrates |
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What are carbohydrates?
Carbohydrates come from a wide array of foods - bread, beans, milk, popcorn, potatoes, cookies, corn etc. They also come in a variety of forms. The most common and abundant are sugars, fibers, and starches. The basic building block of a carbohydrate is a sugar molecule, a simple union of carbon, hydrogen, and oxygen. Starches and fibers are essentially chains of sugar molecules. Some contains hundreds of sugars. Some chains are straight, others branch wildly.
Carbohydrates were once grouped into two main categories. Simple carbohydrates included sugars such as fruit sugar (fructose), corn or grape sugar (dextrose or glucose), and table sugar (sucrose). Complex carbohydrates included everything made of three or more linked sugars. Simple sugars were considered bad and complex carbohydrates good.
What is “slow burning” or “long-lasting” energy?
If we lived a more natural life, any food we would consume would consist of complex carbohydrates that would take time to break down in the body. This would ensure a ‘slow burning’ process providing ‘long lasting’ energy between meals, much like a thick log burning slowly in the fireplace. If, however, the body is supplied with simple, fibreless carbohydrates (such as refined sugar and flour and everything containing them), it’s like paper burning in the fireplace - it gives plenty of heat for a very short time, only to die out very quickly.
What are sugars, “other carbohydrates”?
There are three types of carbohydrates: sugars, starches, and fibers. Each are made up of chains of "sugar blocks". Sugars have only one or two sugar blocks making them simple carbohydrates. Starches and fibers are made up of many connected sugar blocks making them complex carbohydrates.
Simple carb foods
| Table sugar
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| Juices
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| Candy/cookies
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Complex carb foods
| Cereal grains (rice, corn)
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| Whole grains
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| Legumes (beans)
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| Potatoes
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What is glycemic index?
The glycemic index, measures how fast and how far blood sugar rises after you eat a food that contains carbohydrates.
What are the benefits of low GI foods and the problems of high GI foods?
Diets filled with low GI foods, are digested more slowly, causing a lower and more gentle change in blood sugar.
Diets filled with high GI foods, are digested quickly causing a quick and strong increase in blood sugar levels.
Diets filled with high-glycemic-index foods, which cause quick and strong increases in blood sugar levels, have been linked to an increased risk of both diabetes and heart disease. On the other hand, lower GI foods have been shown to help control type 2 diabetes.
What is the link between refined carbohydrates and diabetes?
Refined carbohydrates such as white bread, white rice, sugar-sweetened foods and beverages provide energy, but with less nutritional value and fiber content. They are digested quickly and give rise to a spike in blood glucose levels which the body is overwhelmed to control leading to hyperglycemia and diabetes.
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| Fiber |
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What is fiber?
Basically, the term fiber refers to carbohydrates that cannot be digested. Fiber is present in all plants that are eaten as food, including fruits, vegetables, grains, and legumes. Fibers pass through the digestive system unchanged and is not absorbed by the body. Only plants contain fiber. Animal products do not contain fiber.
Why is fiber beneficial?
Fiber appears to reduce the risk of developing various conditions, including heart disease, diabetes, diverticular disease, and constipation.
What is the function of dietary fiber in our body?
Fiber is important because it has an influence on digestion from start to finish
| Because foods containing fiber have to be chewed more thoroughly, it slows down the eating process and ensures that we do not overeat and that we feel fuller.
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| Because fiber absorbs water the contents of the stomach are bulkier. This creates a feeling of fullness and satiety.
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| It slows down digestion and absorption of food. Hence there is no surge in glucose in the blood and insulin is able to work better.
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| Fiber is broken down in the intestine by the healthy bacteria and this promotes gut health.
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Who should take fiber and how much?
Everyone should take fiber. Current recommendations suggest that adults should consume 20 to 35 grams of dietary fiber per day. The primary source of fiber should be natural foods like fruits, vegetables, legumes, nuts and whole grain carbohydrates. One can also obtain fiber from a number of supplements available in the market.
What are the different types of fiber?
Soluble and Insoluble fibers are the two main types of fiber and they have different effects in our body.
Insoluble fibers are largely made up of the cell walls of plants
| They cannot be dissolved in water
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| They act as a laxative
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| They move the bulk slowly through the intestines
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| Green bran, dark leafy vegetables, fruit and vegetable skins, whole wheat products, bran are some of the good sources of insoluble fiber
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Soluble fibers are made of polysaccharides
| They are soluble in water
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| They prolong gastric emptying time so that glucose is absorbed slowly
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| has beneficial effects on the body like lowering cholesterol and regulating blood glucose
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| Fenugreek, oat bran, psyllium husk, nuts, barley and beans are good sources for soluble fiber.
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What are the best sources of fiber?
The following foods are good sources of dietary fiber
| Whole grains foods such as whole grain breads, pastas, brown rice, cereals, barley, oats and bran.
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| Bran has especially high content of fiber.
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| Legumes like beans and lentils.
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| Fruits like apricots, dates, oranges, apples with skin. Berries like blueberry, strawberry are also rich in fiber.
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| Vegetables like broccoli, spinach, Swiss chard, green peas
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| Nuts and Seeds such as almonds and soy nuts
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Sources of Fiber
| Soluble Fiber | Insoluble Fiber | | Oatmeal | Whole grains
- Whole wheat breads
- Barley
- Brown rice
| | Oatbran | Whole-grain breakfast cereals | | Nuts and seeds | Wheat bran | Legumes
- Dried peas
- Beans
- Lentils
| Seeds | | Apples | Carrots | | Pears | Cucumbers | | Strawberries | Celery | | Blueberries | Tomatoes |
Remember that when foods are processed, the fiber is usually removed. This makes refined and processed foods like white rice, white bread, white sugar poor sources of fiber. When possible, unrefined and unprocessed foods should be taken.
How do I add more fiber to my existing diet?
Here are some tips for including more fiber in your diet:
| Eat whole fruits instead of taking fruit juices. Eat fruits with their skin on.
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| Replace white rice, bread, etc. with brown rice and whole-grain products
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| Choose whole grain cereals rich in fiber for breakfast
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| Snack on vegetables and fruits instead of chips or chocolate bars
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| Take a fiber supplement when needed. Add bran or fenugreek fiber to the refined carbohydrates that you may be currently using
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| Eat a wide variety of foods. This will ensure that you get both soluble and insoluble fibers
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| When possible, substitute beans and legumes for meat.
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Can fiber help me lose weight?
When managing your weight, it is important to eat foods rich in dietary fiber. This is due to a number of reasons:
(1) Fiber-rich foods are generally low in calories, low in fat and are very filling
(2) Intake of Soluble fiber slows down the gastric emptying time and as a result food passes
slowly through the intestine. This ensures that glucose is released into the blood stream more
slowly and therefore we feel have a feeling of fullness for a longer period of time
(3) Intake of fiber rich foods are generally known to keep you full and prevent hinger pangs in
between meals
(4) Instead of eating 3 heavy meals a day, spread the intake of food over five to six times
a day to ensure that you stay satisfied and energetic throughout the day. Eat plenty of fruits
and vegetables during the meals and as a snack.
Remember that taking fiber alone will not result in weight loss. Losing weight requires a change in
lifestyle which includes :
(a) controlling the total calories taken during the day. Fiber rich foods like vegetables, legumes
and fruits tend to help keep the calories low because they tend to be less dense in calories and
are more filling
(b) getting enough exercise so that we burn off the excess calories
Sources : www.ehealthmd.com, www.healthcastle.com
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| Vitamins and minerals |
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What are micronutrients?
Nutritionists call vitamins and minerals "micronutrients" to distinguish them from those nutrients that are present in foods in much larger quantities, such as proteins or fats.
Which micronutrients are important for me?
Multivitamins are important for health. A number of minerals are essential for body functions. They include calcium, phosphorus, potassium, sodium, chloride, sulphur, magnesium, copper, cobalt, chromium, fluoride, iodine, iron, manganese, molybdenum, nickel, selenium, silicon, tin, vanadium and zinc. Other minerals like arsenic, lead and cadmium are toxic.
What is the recommended dietary allowances for micronutrients?
| | Age | Energy | Protein | Vitamin A | Vitamin D | Vitamin E | Vitamin K | | | | k.cal | g | IU | *ug RE | IU | *ug | IU | *mg TE | *ug | | Children | 4-6 | 1,800 | 30/24 | 2,500 | 500 | 400 | 5 | 9 | 7 | -/20 | | 7-10 | 2,400/2000 | 36/28 | 3,300 | 500 | 400 | 5 | 10 | 7 | -/20 | | Males | 15-18 | 3,800 | 54/59 | 5,000 | 1,000 | 400 | 5 | 15 | 10 | -/65 | | 19-24 | 3,000/2,900 | 54/58 | 5,000 | 1,000 | 400 | 5 | 15 | 10 | -/60 | | 25-50 | 2,700 | 56/63 | 5,000 | 1,000 | - | 5 | 15 | 10 | -/80 | | 50+ | 2,400 | 56/63 | 5,000 | 1,000 | - | 10 | 15 | 10 | -/80 | | Females | 15-18 | 2,100 | 48/44 | 4,000 | 800 | 400 | 5 | 12 | 8 | -/55 | | 19-24 | 3,000/2,900 | 54/58 | 5,000 | 1,000 | 400 | 5 | 15 | 10 | -/60 | | 25-50 | 2,800 | 46/50 | 4,000 | 800 | - | 5 | 12 | 8 | -/65 | | 50+ | 1,800 | 46/50 | 4,000 | 800 | - | 5 | 12 | 8 | -/65 |
* First figure refers to the old RDA listing while the second figure refers to the newer DRI listing
Water soluble vitamins*
| | Age | Ascorbic Acid | Folacin/Folate | Niacin | Ribo-flavin | Thia-mine | Vitamin B6 | Vitamin B12 | | | | mg | mcg | mg | mg | mg | mg | mcg | | Children | 4-6 | 40/45 | 200/75 | 12 | 1.1 | 0.9 | 0.9/1.1 | 1.5/1.0 | | | 7-10 | 40/45 | 400/200 | 20 | 1.2 | 1.2/1.0 | 1.2 | 2.0/1.4 | | Males | 15-18 | 40/45 | 300/100 | 16/13 | 1.2 | 1.2/1.0 | 1.2 | 2.0/1.4 | | 19-24 | 45/60 | 400/200 | 20/19 | 1.8/1.7 | 1.5 | 2.0 | 3.0/2.0 | | 25-50 | 45/60 | 400/200 | 18/19 | 1.6/1.7 | 1.4/1.5 | 2.0 | 3.0/2.0 | | 50+ | 45/60 | 400/200 | 16/15 | 1.5/1.4 | 1.2 | 2.0 | 3.0/2.0 | | Females | 15-18 | 45/60 | 400/180 | 14/15 | 1.4/1.3 | 1.1 | 2.0/1.5 | 3.0/2.0 | | 19-24 | 45/60 | 400/180 | 14/15 | 1.4/1.3 | 1.1 | 2.0/1.6 | 3.0/2.0 | | 25-50 | 45/60 | 400/180 | 13/15 | 1.4/1.3 | 1.0/1.1 | 2.0/1.6 | 3.0/2.0 | | 50+ | 45/60 | 400/180 | 12/13 | 1.1/1.2 | 1.0 | 2.0/1.6 | 3.0/2.0 |
* First figure refers to the old RDA listing while the second figure refers to the newer DRI listing
Minerals and others*
| | Age | Calcium | Phosphorous | Iodine | Iron | Magne-sium | Zinc | Sele-nium | Fluoride | | | | mg | mg | ug | mg | mg | mg | *ug | *mg | | Children | 4-6 | 800 | 800/500 | 80/90 | 10 | 200/130 | 10 | -/20 | -/1.1 | | 7-10 | 800 | 800 | 110/120 | 10 | 250 | 10 | -/30 | -/3.2 | | Males | 15-18 | 1200/ 1300 | 1200/1250 | 150 | 18/12 | 400/410 | 15 | -/50 | -/3.8 | | 19-24 | 800/1000 | 800/700 | 140/ 150 | 10 | 350/ 400 | 15 | -/70 | -/3.8 | | 25-50 | 800/ 1000 | 800/700 | 130/150 | 10 | 350/420 | 15 | -/70 | -/3.8 | | 50+ | 800/1200 | 800/700 | 110/ 150 | 10 | 350/ 420 | 15 | -/70 | -/2.9 | | Females | 15-18 | 1200/1300 | 1200/1250 | 115/150 | 18/15 | 300/360 | 15/12 | -/50 | -/3.1 | | 19-24 | 800/1000 | 800/700 | 100/150 | 18/15 | 300/ 310 | 15/12 | -/55 | -/3.1 | | 25-50 | 800/ 1000 | 800/700 | 100/150 | 18/15 | 300/ 320 | 15/ 12 | -/55 | -/3.1 | | 50+ | 800/ 1200 | 800/700 | 80/150 | 10 | 3 00/320 | 15/12 | -/55 | -/3.1 |
What are antioxidants and how do they help?
We'll start with the metabolic villains that scientists call "free radicals." These are unstable molecules that our bodies form in the normal processes of breathing and digesting food. If they're not stopped, free radicals can damage important parts of our cells -- for instance, our DNA. The damage caused can lead to weakened immune systems, cancer and heart diseases.
Antioxidants - "good guys" - whose mission is to wipe out free radicals. Different areas of the body use different kinds of antioxidants. The body manufactures some of these antioxidants in itself. Others must come to us through the food we eat.
What is deficiency or overdose of micronutrients? How will it harm?
Absence or relative deficiency of vitamins and minerals in the diet can lead to a characteristic deficiency state and disease. Large doses are toxic.
Should I watch how much sodium I take?
Sodium plays an essential role in the regulation of blood pressure and blood volume. It also assists with proper muscle contraction and the transmission of nerve impulses. Moderate sodium intake increases resistance to heat cramps and heat stroke, especially during periods of excessive fluid loss through sweating. According to the National Academy of Sciences, the recommended daily allowance (RDA) for sodium is between 1,100-3,300 milligrams/day.
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What is healthy lifestyle?
Food and nutrition
