WHAT DO NUTRITION FACTS LABELS TELL US?

 

WHAT DO NUTRITION FACTS LABELS TELL US?

Almost all food we eat has a nutrition facts label. This label provides the essential values that show the total fat, carbohydrate, protein level and many other information contained in the food. So, what do all these values mean and how are they measured? How can this information help us keep healthy?   For example, you can drink caramel iced coffee every morning, but if you look at nutritional information, a large caramelized coffee in the leading fast food chain has 680 Calories. To burn these calories, you need to ride your bike for an hour at high speed. So what exactly is a calorie? Calorie is a measure of energy. In fact, the term calories people talk about is kilocalories and written as Calorie with capital C. 1 Calorie is the amount of energy required to raise the temperature of 1 kg of water by 1°C at sea level. Calorie quantification was determined by chemist Wilbur O. Atwater in the late 1860s. Atwater built a device called a respiration calorimeter to make direct measurement of heat release by humans from the food they consumed. From 1894 to 1903, Atwater served as Deputy Director of Nutrition Research and, since 1903, as Head of Nutrition Research at the US Department of Agriculture. After prolonged negotiations, Atwater received funding from the government to study human metabolism and to establish a huge respiratory calorimeter. This equipment, whose annual cost exceeded ten thousand dollars, was considered a dream project for the nineteenth century. The calorimeter helped with studies on food analysis, diet development, work energy consumption and digestible foods. It measured human metabolism balance by analyzing the heat and metabolic rate produced by a person performing certain physical activities. It is possible to measure the dynamics of metabolism and the balance between food intake and energy production with this device. The Atwater calorimeter was big enough to allow a person to step into it. It measured the amount of heat they released, the amount of oxygen they consumed and the carbon dioxide they gave off. Using this device, Atwater was able to measure the precise amount of energy contained in thousands of food items. Using this device, Atwater was able to measure the exact amount of energy in food items. He found that carbohydrates and proteins were worth 4 Calories per gram and fats about 9 Calories per gram. This 4-9-4 rule is the main rule of how labels are identified today. If you are wondering how many calories you need each day, the answer depends on your gender, age, and daily activity level. For example, a 17-year-old male with a moderately active lifestyle needs 2,400–2,800 calories per day. If that person has a sedentary lifestyle, that number goes down to 2,200. Calories that we need for daily activities are formed through a process called metabolism in the body cells. Metabolism is a series of chemical reactions in which food breaks down and energy is released. When we get more calories than our body needs, these extra calories are stored as fat for later use. Metabolism is the whole of the biochemical processes that a living thing performs in its body in order to sustain its life. A process called metabolism which occurs in the body cells generates the calories we need for daily activities. Metabolism is a series of chemical reactions in which food is broken down and energy is released. The amount of energy consumed here is also related to the metabolic rate. Basal metabolic rate (BMR) is the number of calories required to keep your body functioning at rest. The amount of energy required for respiration, blood circulation, body temperature control, cell growth and regeneration, brain and nerve functions constitute the BMR. This amount of energy also constitutes the largest percentage (approximately 50–80%) of the energy consumed per day. BMR directly affects the amount of calories a person consumes per day, i.e., weight gain or weight control. However, how calories are produced and used varies from person to person. Therefore, it is said that people's ability to lose weight depends on one's metabolism. People are able to change their BMR by long-term exercise. It has also been reported that people with more muscle and less fat in their body often have a higher BMR. In addition to calories, the nutrition label also displays the amount of three nutrients: fats, proteins and carbohydrates. As it is known, fats are mostly found in vegetable oil products and fish. Proteins are found in milk, meat, beans and nuts. Carbohydrates are found in fruits, vegetables and wheat products. To determine the amount of fat, the food is pre-crushed and continuously washed with organic solvent that dissolves only fats. This method is called continuous extraction with Soxhlet. The amount of oil obtained is determined. This method, which has been used for 100 years, is used today in the production of vegetable and essential oils. However, this method is very slow and complex. A new method uses a technique called nuclear magnetic resonance to measure fat. It exposes the nutrient sample to radiofrequency waves, causing the magnetic moments of protons on the atoms in the sample to rotate. After the radiofrequency is interrupted, the magnetic moments of the protons return to their original state. If this process is carried out at low temperatures and the movement of atoms is slowed down, the oil signals in the sample can be separated from the rest of the signals. So, how much fat should we consume? Experts have reported that 30% of our daily calories should come from fat. So if you consume 2,000 calories in a day, that means no more than 600 calories should come from fat. The standard method used to determine the amount of protein in foods is called the Kjeldahl method. This test is similar to the method that measures the nitrogen content in food. This is because proteins in food often contain nitrogen atoms. In the Kjeldahl method, the sample is boiled in sulfuric acid and then neutralized with sodium hydroxide solution. This converts the available nitrogen into ammonia gas. Ammonia gas is collected in a flask containing boric acid solution. The amount of acid obtained indicates how much protein is present in the sample. So, how much protein do we use every day? Medical institutes recommend that adults consume a minimum of 0.36 grams of protein per kilogram of body weight per day. Thus, a 73 kg adult would have to take about 58 grams of protein. The amount of carbohydrate in food is traditionally calculated instead of measured. In this method, other food components such as protein, fat and water are measured and added together. When the sum is subtracted from the total, the result is assumed to be the total amount of carbohydrates. About half of the calories that we consume should come from carbohydrates in the end. All these data about calories, proteins, fats and carbohydrates help people who are overweight, in particular, make decisions about their food diet. According to the US Centers for Disease Control and Prevention, more than one-third of adults are obese in the USA. This alarming trend reveals the fact that the consumption of sugar in the average American diet is quite high. According to a report submitted to the Turkish Grand National Assembly in 2019 by the World Health Organization, about 3 out of every 4 people in Turkey are overweight or obese, and 1 out of every 3 people are obese. The obese population is 7.5 million and the morbidly obese population is 2.4 million. Obesity has reached epidemic proportions in Turkey as in the world. In addition, childhood obesity is increasing over the world. You better understand what is possible to eat by looking at the nutrition facts label for a healthy diet. So you make healthier decisions about what to include in your diet.

As of 26 July 2018, some rules have been set for innovations in the nutrition facts label. According to this:

1. Data should be submitted for larger portions. 2. The total calorie amount and portion information of the food should be written in large font. 3. The quantities of the components (Vitamin D, potassium etc. required for the body) should also be specified. In addition, the daily dose should be updated and written. 4. The amount of sugar added to the product should be indicated. Returning to the 4-9-4 rule, take your pen and paper in your hand and start calculating. Find the total carbohydrate and protein value on a product's nutrition facts label and multiply each value by 4. Then find the total fat value and multiply it by 9. Add the calculated products. This value gives the total amount of calories in that food. I would like to thank Elle Hughes, Pixabay, Daria Shevtsova, and Fancycrave.com for their support in allowing me to publish their photos. Sultan Funda Görkem Assistant Professor Eskişehir Teknik Üniversitesi Faculty of Science Department of Chemistry