Published: 12/25/2007 - Updated: 08/14/2019
Author: Dra. Loredana Lunadei
Due to the increased prevalence of overweight and obesity in Europe, the role of certain carbohydrates, like sugar, is often the subject of hotly contested debates. The following are data on the role of carbohydrates and sugars and sugar in our diet.
Carbohydrates, sugars and sugar
There are two main types of carbohydrates: sugars and starches. Both provide the same amount of energy per gram (4 kcal). Carbohydrates provide less energy than fat (9 kcal per gram) and alcohol (7 kcal per gram). Fiber is a type of carbohydrate, which unlike the others, is not absorbed in the small intestine to provide energy, despite the fact that there is some metabolism in the large intestine. At least half of the available energy from our diet should come from carbohydrates, particularly starches. Starch is present in cereals (rice, corn, wheat, etc.) Products derived from them (bread, pasta, etc.), Potatoes and vegetables. The sugars include sucrose (or table sugar, which we shall call "sugar"), glucose, fructose, lactose and maltose, and is found naturally in foods such as fruits, vegetables and dairy products. Manufacturers of food and drinks use many of these sugars during processing, as they play important roles. The sugars provide sweetness, texture, structure and consistency to foods. Texture influence on palatability (sensation in the mouth) and, therefore, the acceptance of food. Other functions of the sugars are the preservation of jams and jellies, their contribution to the fermentation of yeast and their contribution to tan color and taste of baked goods. Sucrose (a disaccharide composed of one glucose and one fructose) is a sweet-tasting carbohydrate. It is produced by plants from carbon dioxide (CO2) and water during photosynthesis, using energy from light. Sugar beet and sugar cane produce large quantities of this substance. The sucrose that is extracted from these plants is a natural product, whose properties are not different from the sugar present in fruits and vegetables.
Energy for the brain and muscles
Carbohydrates are important to the functioning of our body. The brain requires an almost constant supply of glucose from the bloodstream. The adult brain uses approximately 140 g of glucose per day, which can amount to 50% of the total carbohydrate being consumed.
Some scientific studies have shown that consumption of a carbohydrate-based food or a sugary drink is associated with greater mental agility, with positive effects on memory, reaction time, attention and ability arithmetic. It has been found that consumption of foods rich in carbohydrates, a snack or a sugary drink has beneficial cognitive effects and helps reduce feelings of tiredness. The adult subjects who participated in a test drive in a car simulator on a long distance (120 km) showed a significantly lower error rates when consuming sugary drinks before the test and during that period, compared with subjects who only drank water. However, the results are not fully conclusive since studies differ in the type of sugar used, the total amount and composition of food consumed. As the body's reserves of glycogen (energy reserves in the short term composed of glucose units) in the liver and muscles are limited, the depletion of muscle glycogen is the major cause of fatigue during anaerobic exercise intense and of long duration (60-90 minutes). Sports drinks that contain sugar and electrolytes, in addition to water, prevent dehydration, delay the onset of fatigue and prevent depletion of glycogen reserves of the body because the sugars that are ingested and pass into the bloodstream which are used muscles in the first place. In situations of intense physical activity and prolonged, the glycogen reserves can be used later.
As to resupply the depleted reserves of glycogen, which is especially important for elite athletes, carbohydrates that are digested and absorbed rapidly stored as glycogen are much more quickly than carbohydrates have a glycemic index (IG) reduced. The GI reflects the extent to which foods raise the level of blood sugar after consumption.
Sugar and body weight
A number of epidemiological studies (which considered the factors affecting the health of the population) in adults, adolescents and children has shown the existence of a clear inverse relationship between sucrose consumption and body weight index body mass (BMI), and between the consumption of sucrose and total fat intake 4.5. In other words, generally, people who consume a high percentage of their energy needs (calories) as sugar less overweight than those who consume a small percentage. Often there is an inverse relationship between the level of sugar consumption and the level of fat consumption as people who consume large quantities of sugar tend to follow a diet less fat. However, some individuals exceed their energy needs, consuming too many calories from both fat and sugar, which over time causes weight gain. The system that regulates our appetite recognizes carbohydrates, including sugars, which promote the feeling satiety. A study on health-related habits in schoolchildren (HBSC-Study in English), conducted by WHO in 2001-2002 to about 140,000 teenagers between the ages of 10 and 16 years from 34 countries (mainly Europe), compared the prevalence of overweight and obesity and its relationship to physical activity and habits. The results showed a significant negative correlation between the consumption of sweets and chocolate and BMI in 31 adolescents from 34 countries. The high consumption of sweets appeared associated with a lower probability of overweight and also there was any association between consumption of sugary soft drinks and overweight. These findings could be due to several confounding factors, children with overweight and obese may have reduced pre-consumption of sweets and chocolate for their weight problem, or have confessed to a lower real consumption of such foods. In a recent British study based on data for 3 days of food records from more than 1,000 children between 5 and 7 years old, sugary drinks accounted for 3% of total energy consumption and there was no association between consumption and adiposity in children of 9 years. Other studies, mostly American, have shown that increased consumption of sugary soft drinks and fruit juices is associated with a higher BMI or weight gain.
Due to the lack of consistent evidence, it is difficult to draw definitive conclusions about the existence of a direct relationship between consumption of sugary soft drinks and increased body weight. Weight gain occurs when energy consumption from food and drink is greater than the energy they burn through metabolism and physical activity. Therefore, it is difficult to establish a relationship between obesity and the consumption of a single food, nutrient or ingredient. Eating too many calories, regardless of their origin, can lead to overweight if those calories are not spent doing something. This happens with any food or drink, or if it contributes to the excessive consumption of energy in relation to energy needs, will be encouraging weight gain. The supply of vitamins and minerals is popularly believed that adding sugar tends to eliminate other foods from the diet and reducing the consumption of vitamins and minerals. However, it has been shown that consumption of added sugar is compatible with a healthy diet and there is no evidence that sugar displaces micronutrients. The nutritional quality of the diet of children, even for the higher consumption of sugar-was adequate with regard to the consumption of vitamins and minerals.
Many people believe that sucrose is the only cause of dental caries. However, all carbohydrates present in foods can cause cavities. Research has proven that not only sugar, honey candies or favors the development of caries, but also other foods rich in carbohydrates that are not sweet, like bread, potatoes, or potato chips. Cavities occur when bacteria in dental plaque ferment starches and sugars producing acids, which are damaging the teeth. Currently, it is considered that good oral hygiene and using fluoride toothpaste are the most important factors in preventing tooth decay and have a good oral health. Since 1970, the prevalence of caries has declined significantly in children and adolescents, although the consumption of sugar has remained stable and the habit of nibbling between meals has increased. Today, most children of 12 years have teeth without caries. Caries can be prevented by washing your teeth twice daily with fluoride toothpaste and limiting the number of times that you eat or drink anything for 6 times a day, while avoiding being pecking and drinking continuously.
Type 2 diabetes has a strong genetic basis and the appearance of symptoms is related to age, obesity and physical inactivity. There is a causal link between sugar consumption and diabetes. At present, the consumption of a moderate amount of sugar in a balanced diet is accepted in the schemes recommended for diabetic people.
- Westenhoefer J. (2006) Carbohydrates and cognitive performance. Aktuelle Ernaehrungsmedizin 31 Supplement 1: S 96-S 102.
- Sunram-Lea SI, Foster JK, Durlach P, Perez C (2001): Glucose facilitation of cognitive performance in healthy young adults: examination of the influence of fast-duration, time of day and pre-consumption plasma glucose levels. Psychopharmacology 157: 46-54.
- Keul J and Jakob E (1990) Zur Wirkung von Saccharose auf Fahrverhalten, Kreislauf und Stoffwechsel. Oesterreichisches Journal fuer Sportmedizin 20: 102-110.
- Bolton-Smith C and Woodward M (1994): Dietary composition and fat to sugar ratios in relation to obesity. International Journal of Obesity 18: 820-828.
- Janssen I et al. (2005) Comparison of overweight and obesity prevalence in school-aged youth from 34 countries and their relationships with physical activity and dietary patterns. Obesity Reviews 6: 123-132.
- Anderson GH and Woodend D. (2003) Consumption of sugars and the regulation of short-term satiety and food intake. American Journal of Clinical Nutrition; 78:(suppl):843S-849S.
- Johnson L et al. (2007) Is sugar-sweetened beverage consumption associated with increased fatness in children? Nutrition 23 (7-8): 557-563.
- Malik VS et al (2006) Intake of sugar-sweetened beverages and weight gain: a systematic review. American Journal of Clinical Nutrition, Vol. 84, No. 2, 274-288.
- Rennie KL and Livingstone MBE (2007): Associations between dietary added sugar intake and micronutrient intake: a systematic review. British Journal of Nutrition 97: 832-841.
- WHO Global Oral health data base. https://www.who.int/oral_health/databases/en/
- Touger-Decker R and van Loveren C (2003) Sugars and dental health. American Journal of Clinical Nutrition. 78 (Suppl): 881 S-892 S.
- Franz MJ., et al. (2002) Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care, 25(1): p. 148-198.
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