DOCSLIB.ORG

The Effect of Sucrose- and Aspartame- Sweetened Drinks on Energy Intake, Hunger and Food Choice of Female, Moderately Restrained Eaters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Effect of Sucrose- and Aspartame- Sweetened Drinks on Energy Intake, Hunger and Food Choice of Female, Moderately Restrained Eaters International Journal of Obesity (1997) 21, 37±42 ß 1997 Stockton Press All rights reserved 0307±0565/97 $12.00 The effect of sucrose- and aspartame- sweetened drinks on energy intake, hunger and food choice of female, moderately restrained eaters JH Lavin, SJ French and NW Read Centre for Human Nutrition, Northern General Hospital, Herries Road, Shef®eld S5 7AU, UK Objective: To compare the effects of aspartame-sweetened and sucrose-sweetened soft drinks on food intake and appetite ratings of female restrained eaters. Subjects: Fourteen female students, shown to have eating restraint. Methods: Subjects were given four drinks (330 ml) of aspartame-sweetened lemonade, sucrose-sweetened lemonade and carbonated mineral water on three separate days. Seven of the subjects were informed of the drink type they were consuming on each occasion. Measurements: Appetite ratings were recorded and energy and macronutrient intakes were measured during the study day and day after leaving the department. Results: During the ®rst study day energy intake was lower whilst drinking the sucrose-sweetened lemonade compared with the aspartame-sweetened lemonade, although neither differed signi®cantly from energy intakes during the day they drank water. When the calories from the sucrose-sweetened lemonade were included (1381 kJ, 330 Kcal) energy intake did not differ between treatments. The following day energy intake was signi®cantly higher after the aspartame-sweetened lemonade compared with both sucrose-sweetened lemonade and the water due to an increase in the amount of carbohydrate consumed and resulted in a higher total energy intake over the two days studied. Knowledge of the drink types had no effect on energy intake or macronutrient intake. Appetite ratings did not differ between drinks and were not affected by knowledge of the drink types. Conclusion: These results suggest that in females with eating restraint, substituting sucrose-sweetened drinks for diet drinks does not reduce total energy intake and may even result in a higher intake during the subsequent day. Keywords: aspartame; sucrose; appetite; energy intake; restrained eaters Introduction tened with aspartame increased hunger compared with a non-sweet control. Most previous studies in this area have examined Energy ingested in the form of carbohydrate has an the effects of covert ingestion of sweeteners on the important effect on appetite regulation. Previous stu- short-term eating behaviour of normal subjects with dies have shown that calories ingested in carbohydrate low dietary restraint. Restrained eaters exert a high supplemented preloads were accurately compensated degree of cognitive control over food intake and many for by a reduction in intake from a subsequent test replace high calorie products with reduced calorie meal when compared with preloads containing arti®- alternatives as a simple means of reducing energy cial sweeteners or left plain.1,2 Thus there was no intake.6 It is not known how consumption of arti®- overall difference in energy consumption when the cially sweetened products would affect later intake in preload and test meal intake were summed. Further- restrained eaters nor how knowledge of consumption more, in some studies, sweetness in the absence of of low calorie items would in¯uence eating behaviour. calories has been shown to stimulate appetite: Rogers Since many arti®cial sweeteners are ingested in the et al3 and Blundell et al4 have shown that ingestion of form of soft drinks,7 the aim of the present study was concentrated solutions of sweeteners increases moti- to compare the effects of soft drinks containing vation to eat compared with water and, similarly, sucrose versus aspartame on appetite ratings and Tordoff and Alleva5 found that chewing gum swee- 48 h energy and macronutrient intake of healthy females of moderate dietary restraint and also to determine how knowledge of the drink type affected Correspondence: Professor NW Read. Received 22 May 1996; revised 20 September 1996; accepted 23 these measures. Food intake over 48 h was studied, as September 1996 energy compensation may not be detected during Effect of sucrose and aspartame on energy intake JH Lavin et al 38 consumption of a single test meal and may only consumed within 15 min. A selection of high carbo- become evident later under ad-libitum conditions. hydrate and high fat snacks were provided for each subject between 09.30 h and 12.30 h and again between 13.30 h and 17.30 h. A self-selection cold lunch was presented between 12.30 h and 13.00 h, and Methods a pre-selected evening meal was served between 17.30 h and 18.00 h. Subjects were served with the Subjects same evening meal on each of the three study days. Studies were carried out on fourteen healthy, normal All foods were weighed before and after presenta- weight female university students recruited by posters tion and were provided in amounts in excess of that placed throughout the University of Shef®eld and by which subjects would normally be expected to eat. word of mouth. Potential subjects completed the Subjects were instructed to eat until comfortably full. Three-Factor Eating Questionnaire (TFEQ)8 and On departure from the Centre at 19.00 h subjects were were asked questions about their eating patterns. provided with a set of weighing scales and food Subjects were selected if their scores on the TFEQ diaries to record all further intake for the remainder indicated dietary restraint (cognitive restraint score of the evening and the following day. Energy intake > 10 out of a possible 21, [13.3 Æ 0.6; mean Æ s.e.]), and percentage energy provided by the macronutrients but were excluded if they were currently dieting or if from the meals consumed at the centre and those they reported, in a question added to the TFEQ, that recorded in the food diaries were calculated using their eating patterns were markedly affected by their information obtained directly from product packages menstrual cycle. and the COMP-EAT dietary analysis package The selected subjects were asked to choose an (COMP-EAT, Lifeline Nutritional Services Ltd, evening meal from a menu list and were randomly London, UK). assigned to either an informed or uninformed study Ratings of hunger, fullness and prospective food group. The informed group were told the nature of the consumption were indicated on 100 mm visual analo- drink they were consuming on each occasion. Each gue scale questionnaires administered at hourly inter- subject gave written consent to participate in the vals from 09.00 h until 12.00 h and from 13.30 h study, the protocol for which was approved by the onwards, and in addition, ®ve minutes prior to and Local Research Ethical Committee Northern General every 15 minutes in the hour following the lunch time Hospital, Shef®eld. In order to disguise the true and evening meals. The last scale being administered at 19.00 h. The scales were adapted from a question- purpose of the study, the subjects were told that it 9 was an investigation into the effects of soft drinks on naire previously published. performance and arousal and asked to complete In between meals subjects were free to read, work simple computer tasks and questionnaires throughout or watch television. the study day. Statistical Analysis Protocol Statistical analysis was performed using SPSS for Subjects came to the Centre for Human Nutrition at windows v. 6.0 (SPSS Inc., USA). Repeated measures 9.00 am on three occasions, each exactly one week analysis of covariance (ANCOVA) was applied to apart, after they had consumed their usual breakfast. ratings of hunger, fullness and prospective consump- They were given a different drink type on each test tion, with drink type and time of rating as within- day in a randomised order. These were normal subject factors and knowledge of drink type as a sucrose-containing lemonade, diet aspartame-contain- between subject factor. Baseline ratings were used ing lemonade and carbonated mineral water (Safeway, as covariates. Energy and macronutrient intakes were Table 1). Subjects attending the Centre on the same evaluated using analysis of variance (ANOVA) with day were in the same study group thus preventing the drink type as a within-subject factor and knowledge as uninformed group obtaining information of the drink a between subject factor. Post hoc Scheffe tests were type from the informed group. employed when differences due to drink type were Drinks (330 ml) were administered to the subjects observed. A P value of < 0.05 was considered sig- at 09.30 h, 11.30 h, 14.00 h and 16.00 h and were ni®cant. Table 1 Nutritional composition of the test drinks (expressed as total intake, 4 6 330 ml) Drink Nutritional composition/1320 ml Energy (kJ) Carbohydrate (g) Fat (g) Protein (g) Aspartame-sweetened lemonade < 42 0 0 0 Sucrose-sweetened lemonade 1381 79.2 0 0 Carbonated mineral water 0 0 0 0 Effect of sucrose and aspartame on energy intake JH Lavin et al 39 Figure 1 Hunger and fullness ratings during the ®rst study day. ASL aspartame-sweetened lemonade, SSL sucrose-sweetened lemonade, CMW carbonated mineral water. D test drink, L lunch meal, E evening meal. Results onade (P < 0.01; Figure 2). However, neither energy intake during these two treatments were signi®cantly different from that observed during the day they were Analysis of variance revealed no effect of knowledge consuming carbonated water. When the energy from of the drink type on appetite ratings, energy intake or the sucrose-sweetened lemonade (1318 kJ, 330 kcal) macronutrient intake throughout the study. Therefore was accounted for there was no difference in overall the data from the informed and uninformed groups are energy intake between the three treatments (Figure 2). combined and presented as results for all 14 subjects.
Load more

Recommended publications
  • Popular Sweeteners and Their Health Effects Based Upon Valid Scientific Data
    Popular Sweeteners and Their Health Effects Interactive Qualifying Project Report Submitted to the Faculty of the WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science By __________________________________ Ivan Lebedev __________________________________ Jayyoung Park __________________________________ Ross Yaylaian Date: Approved: __________________________________ Professor Satya Shivkumar Abstract Perceived health risks of artificial sweeteners are a controversial topic often supported solely by anecdotal evidence and distorted media hype. The aim of this study was to examine popular sweeteners and their health effects based upon valid scientific data. Information was gathered through a sweetener taste panel, interviews with doctors, and an on-line survey. The survey revealed the public’s lack of appreciation for sweeteners. It was observed that artificial sweeteners can serve as a low-risk alternative to natural sweeteners. I Table of Contents Abstract .............................................................................................................................................. I Table of Contents ............................................................................................................................... II List of Figures ................................................................................................................................... IV List of Tables ...................................................................................................................................
    [Show full text]
  • The Identification of Key Foods for Food Composition Research
    JOURNAL OF FOOD COMPOSITION AND ANALYSIS (2002) 15, 183–194 doi:10.1006/jfca.2001.1046 Available online at http://www.idealibrary.comon ORIGINAL ARTICLE The Identification of Key Foods for Food Composition Research D. B. Haytowitz1, P. R. Pehrsson, and J. M. Holden Nutrient Data Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, 10300 Baltimore Avenue, B-005, Rm. 307A, BARC-West Beltsville, MD 20705, U.S.A. Received January 3, 2001, and in revised formNovember16, 2001 The United States Department of Agriculture’s (USDA) National Food and Nutrient Analysis Program(NFNAP) was initiated to update existing component values and to add data on new foods and components to reflect today’s marketplace and needs for data. The USDA Nutrient Database for Standard Reference contains data for about 6040 foods for over 100 compounds. To develop a full nutrient profile for each food costs approximately $12 000 (six analytical samples  $2000 per sample). To determine food sampling priorities, the Nutrient Data Laboratory (NDL) has used the Key Foods approach to generate a list of 666 foods. This method utilizes existing nutrient profiles and nationally representative food consumption survey data collected by USDA in the Continuing Survey of Food Intakes by Individuals 1994–1996 (CSFII) and by The U.S. Department of Health and Human Services (USDHHS) in the National Health and Nutrition Examination Survey (NHANES). One premise of the project is that more samples will be collected and prepared for those foods which provide important amounts of nutrients of public health significance to the diet and not every sample will be analyzed for all the nutrients currently in NDL’s nutrient databases.
    [Show full text]
  • Cost-Saving Energy Solutions for Food Businesses
    Cost-Saving Energy Solutions for Food Businesses Restaurants, coffee shops and grocery stores serve as hubs of commerce and social activity in many downtown commercial districts and can be a key ingredient for a viable rural community. Many of these businesses have a substantial opportunity to Adjusting the defrost lower overhead costs and increase their profit margins by replacing equipment and cycle of refrigeration reducing energy costs. Making changes like sourcing locally, re-using food waste and considering renewable energy are also possible solutions for long-term sustainability. equipment can result in a significant energy and cost savings. Energy Efficiencies One restaurant owner Intensity with Replacing was able to save $800 annually by of Food and Operating shortening the defrost Businesses Equipment cycle from 70 minutes Food-based businesses are energy-intensive Energy savings can be achieved simply through to 15 minutes. businesses, using large amounts of electricity operation and management changes of and natural gas for cooking, food processing and equipment. Higher upfront costs for upgrading refrigeration. For example, about 24 percent of to more energy efficient equipment can be a energy in restaurants is used for cooking. deterrent for business owners on a tight budget. However, federal, state and utility incentives Virtually every aspect of running a food-based can often offset or exceed the up-front cost of business is affected by energy and energy prices. high-efficiency equipment. In addition to cost, They face high energy costs due to electricity reliability is a key requirement in both restaurants and gas demand from griddles, fryers, steam and grocery stores.
    [Show full text]
  • Incorporating Away-From-Home Foods Into a Healthy Eating Plan
    Incorporating Away–From–Home Food into a Healthy Eating Plan Summary Much of this brief is based upon a In our often time-pressed society, convenience is a recently published way of life for many individuals. Foods and meals report: The prepared outside of the home are an increasingly Keystone Forum 1, 2 important part of the American diet. This is a on Away-From- trend that has coincided with a dramatic rise in the Home Foods: prevalence of obesity. While food, wherever prepared, Opportunities for is not the only factor affecting body weight, away- Preventing Weight from-home food should be an important consideration Gain and Obesity.3 for people aiming to maintain or lose weight. A The report resulted growing body of literature indicates that the eating from consensus of away-from-home food can be a factor influencing building workshops energy intake. Informed choices pertaining to away- which included from-home food could help reduce calorie over­ participants from consumption and aid in weight management. the private sector, nongovernmental The objectives of this brief are to: organizations, Summarize environmental and societal changes academia, and government to “identify the state of that may contribute to the increased consumption of the evidence, as well as, important knowledge gaps, away-from-home food. regarding obesity and weight gain prevention and away-from-home foods.” Review the properties of away-from-home-food that may facilitate the over-consumption of energy. In this brief, away-from-home food refers to food Examine studies investigating the relationship of prepared and purchased outside of the home.
    [Show full text]
  • Choice of Foods and Ingredients for Moderately Malnourished Children 6 Months to 5 Years of Age
    Choice of foods and ingredients for moderately malnourished children 6 months to 5 years of age Kim F. Michaelsen, Camilla Hoppe, Nanna Roos, Pernille Kaestel, Maria Stougaard, Lotte Lauritzen, Christian Mølgaard, Tsinuel Girma, and Henrik Friis Abstract quality, especially PUFA content and ratios, in children with moderate malnutrition. There is consensus on how to treat severe malnutrition, but there is no agreement on the most cost-effective way to treat infants and young children with moderate mal- Introduction nutrition who consume cereal-dominated diets. The aim of this review is to give an overview of the nutritional Child malnutrition is a major global health problem, qualities of relevant foods and ingredients in relation leading to morbidity and mortality, impaired intellec- to the nutritional needs of children with moderate mal- tual development and working capacity, and increased nutrition and to identify research needs. The following risk of adult disease. This review will deal with the general aspects are covered: energy density, macronutri- needs of children between the ages of 6 months and ent content and quality, minerals and vitamins, bioactive 5 years with moderate malnutrition. Infants below 6 substances, antinutritional factors, and food processing. months of age should (ideally) be exclusively breastfed, The nutritional values of the main food groups—cereals, and if malnourished, will have special needs, which will legumes, pulses, roots, vegetables, fruits, and animal not be covered here. Moderate malnutrition includes all foods—are discussed. The special beneficial qualities children with moderate wasting, defined as a weight- of animal-source foods, which contain high levels of for-height between –3 and –2 z-scores of the median minerals important for growth, high-quality protein, of the new World Health Organization (WHO) child and no antinutrients or fibers, are emphasized.
    [Show full text]
  • An Energy Shuttle for Biosynthesis Key Terms: ATP, NADH, FADH
    Chapter 8 Metabolism Chapter Outline I. Energy: Fuel for Work. *Energy is necessary to do any kind of work. The body converts chemical energy from food sources—carbohydrates, proteins, and fats—into a form usable by cells. A. Transferring food energy to cellular energy (Figure 8.2) B. What is metabolism (Figure 8.3)? *Anabolic reactions (anabolism) build compounds. These reactions require energy. Catabolic reactions (catabolism) break compounds into smaller units. These reactions produce the energy. C. The cell is the metabolic processing center (Figure 8.4) Key terms: metabolism chemical energy, photosynthesis, metabolite, metabolic pathway, catabolism, anabolism, cell, nucleus, cytoplasm, cytosol, organelle, mitochondria, cofactor, coenzyme II. Who Are the Key Energy Players? A. ATP: The Body’s Energy Currency (Figure 8.5). *Adenosine triphosphate (ATP) is the energy currency of the body. B. NADH and FADH2: The Body’s Energy Shuttles. *The body’s energy shuttles NADH, FADH2, and NADPH are important carriers of hydrogen and high-energy electrons. NADH and FADH2 are used in making ATP, while NADPH is used in biosynthetic reactions. C. NADPH: An Energy Shuttle for Biosynthesis Key terms: ATP, NADH, FADH2, NADPH, biosynthesis, ADP, pyrophosphate, AMP, GTP, NAD, hydrogen ion, FAD III. Breakdown and Release of Energy. *Cells extract energy from carbohydrate via four main pathways: glycolysis, pyruvate into acetyl CoA, the citric acid cycle, and the electron transport chain. A. Extracting Energy from Carbohydrate (Table 8.1). *The citric acid cycle and electron transport chain require oxygen. Glycolysis does not. 1. Glycolysis 2. Conversion of pyruvate to acetyl CoA 3. Citric acid cycle 4.
    [Show full text]
  • Energy (In)Efficiency of the Local Food Movement: Food for Thought
    Fordham Environmental Law Review Volume 23, Number 1 2011 Article 3 Energy (In)Efficiency of the Local Food Movement: Food for Thought Lauren Kaplin∗ ∗Harvard Law School Copyright c 2011 by the authors. Fordham Environmental Law Review is produced by The Berkeley Electronic Press (bepress). http://ir.lawnet.fordham.edu/elr ENERGY (IN)EFFICIENCY OF THE LOCAL FOOD MOVEMENT: FOOD FOR THOUGHT Lauren Kaplin* INTRODUCTION "Eating local" is a growing trend in the American food system, with environmentalists and foodies alike advocating for shorter food transportation distances from farm to table.2 Not only have local food systems gained followers through farmer's markets, locally sourced restaurants, and community supported agriculture ("CSA") enterprises, but the "locavore" 3 trend has begun to gain momentum in Washington as well: various state administered programs supporting Lauren Kaplin received her J.D. from Harvard Law School in 2011, and she is currently a Sinclair Kennedy Traveling Fellow. She is grateful to Professor Jody Freeman and her Energy and Climate Law and Policy class. 1. STEVE MARTINEZ ET AL., LOCAL FOOD SYSTEMS: CONCEPTS, IMPACTS, AND ISSUES, ECONOMIC RESEARCH REPORT NUMBER 97, 3 (May 2010). "Terms such as "local food," "local food system," and "(re)localization" are often used interchangeably to refer to food produced near its point of consumption in relation to the modern or mainstream food system." The meaning of "local" differs based on context, and can range from 100 miles (according to the New Oxford American Dictionary's definition of "locavore") to 400 miles (according to the 2008 Farm Act). Id. Other definitions include considerations of production methods, sustainability, the amount of processing, and the characteristics of the farmer or farm, but for the purposes of this Note, the term "local" will refer to the distance between place of origin and consumption.
    [Show full text]
  • Energy Production in a Cell (Chapter 25 Metabolism)
    Energy Production In A Cell (Chapter 25 Metabolism) Large food molecules contain a lot of potential energy in the form of chemical bonds but it requires a lot of work to liberate the energy. Cells need a quick easy way to get energy for anabolism: this is done with ATP. ATP is an unstable molecule, the bonds of which are easy to break making it a useful source of energy for cells. ATP → ADP + P + free energy from food Food energy + ADP + P → ATP Catabolic reactions generate energy to make ATP, and the ATP energy is used to drive anabolic reactions, such as metabolic turnover (replacement of cell parts), growth and cell division, and special functions (such as secretion, absorption, contraction, or signaling). Metabolism = the sum of all chemical reactions in the body; catabolism + anabolism All energy production begins in the cytosol of the cell. Large molecules are catabolized into smaller molecules, but very little energy is produced: Proteins → amino acids Triglycerides → fatty acids and glycerol Carbohydrates → short carbon chains These smaller molecules are then absorbed and processed in reactions inside the mitochondria. 40% of the energy is captured to produce ATP from ADP and the remaining 60% escapes as heat (used to maintain body temperature). Oxidation-Reduction Reactions (Redox Rxns) Oxidation = the removal of electrons (or addition of oxygen) Reduction = the addition of electrons These reactions are always coupled: one molecule must be oxidized while another is reduced. A-e’ + B → A + B-e’ (A is oxidized while B is reduced) The reduced molecule gains energy while the oxidized molecule loses energy.
    [Show full text]
  • Measurement of Energy in Food and During Physical Activity 171
    98421_Ch06 12/28/07 10:15 AM Page 170 Chapter 6 Measurement of Energy in Food and During Outline Measurement of Food Energy I The Calorie—A Unit of Energy Physical Activity Measurement I Gross Energy Value of Foods I Net Energy Value of Foods I Energy Value of a Meal Measurement of Human Energy Expenditure I Energy Released by the Body I The Respiratory Quotient I The Respiratory Exchange Ratio I Measurement of Human Energy Generating Capacities I Energy Expenditure During Rest and Physical Activity I Factors Affecting Energy Expenditure I Energy Expenditure During Physical Activity I Average Daily Rates of Energy Expenditure I The Metabolic Equivalent (MET) 98421_Ch06 12/28/07 10:15 AM Page 171 Chapter 6 Measurement of Energy in Food and During Physical Activity 171 Answer these 10 statements about the measurement of energy in food and during physical activity. Use the scoring key at the end of the chapter to check your results. Repeat this test after you have read the chapter and compare your results. 1. T F The calorie is a unit of energy measurement. 2. T F The bomb calorimeter operates on the principle of indirect calorimetry by measuring the oxygen consumed as the food burns completely. 3. T F Heat of combustion refers to a food’s ability to release carbon dioxide in relation to oxygen consumed as it burns completely. 4. T F The heat of combustion for all carbohydrates averages 5.0 kCal per gram. 5. T F The heat of combustion for lipid averages 6.0 kCal per gram.
    [Show full text]
  • Famines and Economics
    __/PS tGqS POLICY RESEARCH WORKING PAPER 1693 Famines and Economics Factorsthat increase vulnerability to famine include poverty, weak social and Martin Ravallion physicalinfrastructure, a weak and unprepared government, and a relativelyclosed political regime. The World Bank Policy Research Department Poverty and Human Resources Division December 1996 | POLIcY RESEARCHWORKING PAPER 1693 Summary findings Defining famine as widespread, usually life-threatening, institutions that work adequately, though not perfectly, hunger or starvation, Ravallion observes that famine has in normal times can fail under unusual stresses. Poor occurred in most parts of the world in the twentieth people can then be highly vulnerable. century, killing many people. But famines are surely Famine can be viewed as a tragic magnification of more avoidable now than ever before. normal market and governmental failures, says Ravallion. Famines defy simple explanations and geographic And the factors that can transform a shock into mass boundaries, says Ravallion. They have happened under starvation seem to be intrinsic features of normal both socialist and capitalist economic systems, and with economies rather than peculiar features of highly and without wars or unusual political or social instability. distorted or badly managed economies. Normally they And economic analysis can help explain famines that in are hidden from view, but they can surfacein a number the past have been explained in terms of often doubtful of ways. single causes, such as a decline in aggregate food Certain elements increase a region's vulnerability to production. famine: Under certain conditions, the threat of mass starvation * Poverty. can emerge from seeminglysmall shocks to an economy, * Weak social and physical infrastructure.
    [Show full text]
  • Part D. Chapter 1: Current Intakes of Foods, Beverages, and Nutrients
    Part D. Chapter 1: Current Intakes of Foods, Beverages, and Nutrients PART D. CHAPTER 1: CURRENT INTAKES OF FOODS, BEVERAGES, AND NUTRIENTS INTRODUCTION ..................................................................................................................... 3 LIST OF QUESTIONS ............................................................................................................ 5 METHODOLOGY .................................................................................................................... 5 Food and Nutrient Intakes .................................................................................................. 5 Nutrients or Food Components of Public Health Concern ................................................. 6 Evaluation of Dietary Intake Data ....................................................................................... 9 Nutrition-related Chronic Health Conditions ....................................................................... 9 REVIEW OF THE SCIENCE ................................................................................................. 10 Question 1: What is the current prevalence of nutrition-related chronic health conditions? ............................................................................................................ 10 Approach to Answering Question: Data analysis ........................................................... 10 Conclusion Statement ...................................................................................................
    [Show full text]
  • ENERGY and ITS USE DURING EXERCISE by Dr. John Troup, U.S
    ENERGY AND ITS USE DURING EXERCISE By Dr. John Troup, U.S. Swimming This article appeared in Australian Swim Coach News, March 1987 THE ENERGY MOLECULE OF THE BODY All organisms require energy to do biological work. For the human, this work includes the transport of materials across cell membranes, the conduction of nerve impulse and the contraction of skeletal and heart muscle. The energy is obtained from the breakdown of a high energy chemical compound called adenosine triphosphate (abbreviated ATP) located in all the body’s cells. “Triphosphate” refers to the fact that this molecule has three (3) phosphates (P) attached to it. When it breaks down, one of the phosphates is split off, releasing energy which can be used by the cell… (1) ATP ADP + P + “useful energy” The problem is that very limited amounts of ATP are available in the muscle cell, probably only enough to sustain muscle contractions for about three seconds. ATP is the universal energy molecule; it must be present if work is to be done. The problem of the cell is to reform ATP from its component parts, ADP and P. Basically, this process is a reverse of the chemical reaction listed as equation (1) above. (2) ADP + P + “energy” ATP Notice that the process of ATP formation and breakdown is cyclic… Notice also that it TAKES ENERGY to link the ADP and P to make ATP. The energy needed to reform ATP comes from that stored in the energy yielding foods from the diet – carbohydrate, fat and protein. These foods or nutrients are broken down in stepwise chemical reactions within the cell, at certain points giving off energy which can be used to remake the ATP.
    [Show full text]