Tuesday, October 19, 2010

Nutrition Labels – How to read

Almost all food items that are packaged and sold now a days have the ‘Nutrition Information‘ panel towards the back side of the package. Though it is a part of a mandatory requirement, issued by the Governments, it also helps identify the composition of the food we are consuming. It is also helpful in planning our daily diet, in-between snacks etc.
It is necessary to understand what it stands for and how it is applicable to our daily lives, especially in case we are dealing with lifestyle problems like diabetes, obesity etc.

The panel is usually in the form of a table denoting the composition, quantity and the number of calories for each macro-nutrient and micro-nutrient, and is distributed as Total Energy, Proteins, Carbohydrates, Fats, saturated fats, sugars, sodium and other essential nutrients like Vitamins and minerals.
The number of calories - expressed in absolute values or percentages of Daily Value - are per serving or per cup or for a given amount, usually expressed in grams (e.g. quantity per 100 g). Percentage of daily values denotes how much of that nutrient - fat, sugar or a vitamin in one serving will give you compared to how much you need for the entire day.
A serving size is usually based on how much amount a person would normally eat and may differ from product to product and also location. Thus a serving size need not be the entire amount, sold in one pack. For example, if there are 100 g of chips in a packet, and the nutritional information mentions all values are for one serving – which is 50 g of chips, then all the values need to be multiplied by 2 to obtain the total calorie intake by consuming the packet.
This same fact has been used to the advantage of the manufacturers. For example, usually there are separate values for ‘fat’ and ‘sugars’, and thus a product can be ‘fat-free’ and yet add calories from ‘sugars’, which can be as bad as calories form fat!

Here is a guide to help understand how to interpret the values mentioned in the table –

Energy – expressed in calories (Cal) or kilojoules (kJ), it represents the total energy supplied by an amount equal to the serving size or in 100 g of the product. It mainly depends on the individual macro-nutrients like fats, proteins and carbohydrates. Many times, there is a separate heading which mentions the calories, specifically from fat.
Though, food is basically consumed to satisfy energy requirements, it is important to know what macro-nutrient is supplying the energy. Calories from proteins and carbohydrates are used up for body maintenance, repairing the wear and tear in the body and supplying energy for activities of daily living.
Calories from fat are prone to storage and hence can add to body fat and weight too.

Nutrition labels or the nutritional information provided behind most food items these days can supply great information about the levels of different macro - and micro – nutrients included in them which can help regulate the quantity we intake.
The most important macro-nutrient is fat, and which appears on the label in a minimum of three and a maximum of six categories. They are Total fat, Saturated fat, Cholesterol, Poly Unsaturated Fatty acids, Mono unsaturated Fatty acids, Trans Fatty acids.

Total fat represents expressed in Kcal, the total calories from all kinds of fats in a given serving or complete quantity of the item. In case it is expressed in grams, then we can obtain the calorie count by multiplying the value in grams by 9.
Saturated fat usually appears solidified at room temperature, due to its saturated molecular structure. This kind of fat can cause greater harm since it may tend to solidify inside the body as well, and clog the arteries, leading to cardio vascular problems, stroke or atherosclerosis etc. It is therefore recommended to reduce the intake of these, as much as possible.
Unsaturated fats appear in the liquefied form at room temperature and are further sub-divided as Poly unsaturated and mono-unsaturated. Due to their very nature, they do not posses much risk to the body, and are better options.
Cholesterol is an sterol transported through the blood and has important functions in the body, unlike the negative image that has been associated with it. Usually cholesterol is present only in sources from animal origin, like poultry and dairy products, different kinds of meat etc. Plant sources do not have any cholesterol content. This is often used as an attraction factor on many ‘low-fat’ or ‘cholesterol free’ food items to lure the customers into buying them, since cholesterol has long been targeted to be a trouble-maker.
Trans fatty acids, usually generated during hydrogenation of oils (preferred for commercial purposes) poses the maximum risk on the body. It is present in most bakery items, since the hydrogenated oil adds texture to the bakery item and hence is commonly used. It is known to increase the levels of bad cholesterol (LDL) in the body and also affect the cells lining the blood vessels negatively and hence is considered harmful.

Thus, lower the levels of saturated fatty acids, cholesterol and trans fatty acids, safer is the consumption.

The other macronutrients mentioned on the label are Carbohydrates and Proteins. Proteins are usually expresses in their total amount, unlike carbohydrates and fats which are further dissected into constituent parts. The general rule of thumb, is the lesser the fats (all kinds) and more the proteins, the better it is, while with carbohydrates, lesser the sugar and more the fiber, the better it is.

Carbohydrates are also the primary contributors to the total energy content. They can come from the sugar (glucose) content in the food item, as well as from the fiber present in it. While carbohydrates from sugar do not provide much nutrition, and instead add to the glucose levels in the blood and the body. This may be harmful in the long run, since increased glucose levels in the body are the major cause of lifestyle disorders like diabetes, obesity and more.
Most of the complex carbohydrates are usually low in sugar and high in fiber. A high fiber (soluble or insoluble) content is good for health, since it provides roughage and eases the bowel movement. Some soluble fibers also help reduce cholesterol and enhance overall health.

Some of the micronutrients include sodium, vitamins and essential minerals like Calcium, magnesium, potassium etc. A low level of sodium (from salt) content is ideal, since excess sodium causes problems like dehydration, excess pressure on the kidneys etc. Calcium and the other minerals are essential for proper nervous system functioning, neuro-muscular co-ordination as well as for many other processes in the body. Including them through your diet is better than taking additional supplements. Though sometimes it does become essential to take additional supplements, since absorption of these minerals depends on many factors including the quantity consumed!

Vitamins like A, E, B complex group and more become essential due to their contribution to the various processes in the body, health of the organs and making up various hormones in the body.
The vitamins and minerals are usually expressed as percentages of daily value (standard values based on the demography, the genetic history etc.) which may be country, age and gender specific, and are easily available in standard nutrition charts.

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