Why Do We Eat 4 25 14 11 28 AM Why Do We Eat pdf version of lecture Learning Objectives 1 Explain the difference between appetite and hunger and explain the factors that in uence eating 2 Identify the differences between taste and aroma 3 Discuss the impact aroma has on the taste of food Food Food means a lot of different things to people An appreciation for how food is perceived and the factors that affect the desire for food can help in understanding a number of eating problems faced by society What is food De nition from The Living Webster Encyclopedia Dictionary A nourishing substance taken into and absorbed by an organism to sustain life and enable growth and repair of tissues more or less solid nutriments as opposed to drink a particular kind of nutriment as a breakfast food something for consumption or use as food for thought De nition from Paul Lachance Food equals known chemical and unknown chemicals which may be modi ed by intentional additives and or contaminants which may be modi ed by maturation storage processing preparation which may be modi ed by digestion absorption metabolism the end products of which may have a good bad or no effect on the body s cells and tissues The above de nition suggests that if a chemical enters our body it is food Some might not agree with this broad a de nition but it is vague enough to be fairly accurate Medically any substance that the body can take in and assimilate that will enable it to stay alive and to grow the carrier of nourishment Many factors including social and religious components can in uence our eating behaviors and typically de ne a limited number of substances accepted by each culture or religion as acceptable or appropriate foods The social limitations may be part of the culture or they may be personal For example in the United States is a worm considered food What if you were starving In the United States most people would only consider eating worms as a survival tool when stranded in the outdoors The reality is that humans in almost 90 countries eat insects and worms and in some parts of Asia Africa and Latin America people regularly eat worms In fact people who eat insects regularly as part of the culture typically do so out of necessity Several religions impose dietary restrictions concerning what is acceptable to eat For example kosher foods are those that conform to the regulations of the Jewish Halakhic law framework Muslims are guided by Halal Islamic dietary guidelines The word Halal means permitted or lawful Seventh day Adventists provide good eating guidelines and many are Lacto ovo vegetarian Some people follow these or other dietary restrictions for reasons other than religion For example some people are vegetarian for ethical reasons https carmen osu edu content 1144 FDSCTE 2200 fdscte 2200 su2 ssionVal c2xBQucKb01NVg1kpyOBu2wYZ ou 11349922 d2l body type 3 Page 1 of 11 Why Do We Eat 4 25 14 11 28 AM Disease management Some modify what they eat because of medical advice or because of perceived health bene ts For example Hypertension limit sodium Coronary heart disease limit cholesterol Diabetes monitor sugar Antioxidants eat chocolate and drink red wine In today s world of marketing we have to be careful that we do not consume food for one attribute that is perceived to be healthy and ignore other properties of the food It probably does not make much sense to eat a pound of chocolates a day for their antioxidants and ignore the calories that are consumed with them We are not sure that the antioxidants in chocolate have any bene t but we know what happens when excess calories are consumed Why do we eat food To obtain nutrients To satisfy hunger Habit To give pleasure To give relief from stress or disease Psychosocial reasons This is a partial list of the reasons that are often given for why people eat For many organisms the list would stop at the rst or maybe the second reason Most animals when presented an endless source of food will only consume what they need to maintain their body weight or to satisfy other needs if they are growing You can give a caged white rat all the food it can eat and it will maintain its normal body weight A quick look around the campus suggests that this is not true for all humans While many can and do maintain an ideal body weight others weigh too much and some too little To provide nutrients Energy Water Carbohydrates Lipids Proteins Vitamins Minerals Each of the nutrients on this list except water will be discussed in more detail in the nutrition section of the course You should know what these nutrients are We will spend some time on energy later but you should know that in the body the molecule used by cells for energy is ATP When you eat food the process of digestion is there to absorb the nutrients that you need and to convert some of them into a https carmen osu edu content 1144 FDSCTE 2200 fdscte 2200 su2 ssionVal c2xBQucKb01NVg1kpyOBu2wYZ ou 11349922 d2l body type 3 Page 2 of 11 Why Do We Eat 4 25 14 11 28 AM form of energy that can be used by cells This latter step involves the conversion of fat protein and carbohydrates macro nutrients into ATP Some lipid and protein components are also required for non energy reasons that will be discussed later Vitamins and minerals are micro nutrients The body requires less of them and they do not provide calories You may require certain vitamins or minerals for metabolism to work but they themselves are not a source of energy The brain controls hunger It involves a series of chemical messages that either signals you to eat or to stop eating This is really a survival mechanism Hunger is hard to ignore The brain is sending messages to the body that it must consume food to survive There are a number of signals that tell you to eat and some that signal that you have consumed enough If the brain is going to err it will err on the side of over consumption Better to eat a bit too much and gain weight than to eat too little and starve Some signals involved in hunger are Go signals Neuropeptide Y NPY an extremely potent stimulator of feeding behavior nutrients in blood stream size and composition of previous meal customary eating patterns weather Hot decrease food intake exercise sex hormones physical and mental disease states Stop signals Stomach distension Nutrients in bloodstream Hormonal and neural signals hypothalamus It is not important that you know these signals You should realize that true hunger exists as a means of survival