Fall 2022 Mid-Term Food and Energy Exam Solutions at Kansas State University
Here are free mid-term exam solutions on food and energy. The exam was done at Kansas state university in fall 2022. In case you’re thinking about hiring a professional nutritional science exam solver to help you excel, we have your back. We help with biology exams of all kinds at an affordable rate online.
Discuss The Main Types of Macronutrients in Food
Most human food goes to produce energy; only a small fraction is used for the growth, repair, and replacement of tissues. Vitamins, water, and minerals in the diet produce no energy. Instead, it all comes from the burning of carbohydrates, protein, and fat fuel in the ratio of 4:4:9 for any given weight of these three. It is entirely correct to refer to them as fuel. Just because something is eaten, digested, and then acted upon during metabolism in the presence of oxygen does not make it any different from a lump of coal burning in the grate. I lb. ( ½ kg.) of coal produces about as much energy as a man needs from his food in one day.
The energy potential of a piece of food, say can be discovered most physically by placing it inside a calorimeter (essentially just a can), burning it in the presence of oxygen, and measuring the amount of heat produced by the combustion. Both sandwich and coal will be ash at the end of the experiment, and an eaten sandwich will have been just as emphatically consumed by the body.
How Are Energy Requirements in Humans Quantified?
The energy of coal and sandwiches are both measured in heat units, namely calories. A single calorie is the amount of heat required to raise the temperature of one gram of water by I°C. This is too small a unit of heat for most measurements of the energy of food; therefore, the kilocalorie is used. This unit, one thousand times larger, can heat one kilogram of water by 1°C. Unfortunately, the precise term kilocalorie is forgotten in nearly all discussions about food, and the word calorie is used. The daily human requirement of some 3,000 calories is truly 3,000 kilocalories, or enough to heat 3,000 kilograms of water through. 1°C, or 30 kilograms of water through 100°C, or enough to maintain an active human being throughout twenty-four hours.
Human needs have a touch of economics about them; there seem to be as many opinions as there are experts. (Perhaps there are not enough experts. University chairs for animal nutrition tend to outnumber those for human nutrition.) Essentially there is the basic metabolic need, the actual cost of maintaining a warm, healthy, and resting body. On top of this comes the cost of doing physical work, whether sewing or coal mining.
How Do Calorie Requirements in Men and Women Compare?
The basic need has been calculated as 40 calories an hour for every square meter of a man's bodily surface area, and 37 calories for every female square meter (or roughly 3.7 and 3-5 calories per square foot). The difference in surface area between a lissom young girl and some blacksmith of a man is not as great as might be expected; and can be determined if both weight and height are known. Some examples are:
|The surface area of the body Basic needs per hour|
|Weight||Height||Sq. meters||Sq. feet||Man||Woman|
|7 Stone||4’ 10”||1.355||14.5||54||50|
Therefore, between the short, light girl and the 6 ft. 4 ins. (1-9m.) heavyweight who could carry her off with ease, there is double the weight but only 63% more surface area, a mere 9 square feet or 0-8 square meters, or the top of a card-table 3 ft. by 3 ft.
The difference in basic energy needs between the two is greater owing to the more demanding metabolism of the male. She is 7 stone (44.5 kgs.) and 4 ft. 10ins. (1-5m.), needs a basic 1,200 calories a day while he, if 14 stone (89 kgs.) and 6 ft. 4 ins. (1.9 m.), needs a basic 2,090, quite apart from the energy needed to lift her and carry her off. Work done usually demands at least as much energy as the basic need.
Briefly Explain Calorie Requirements According to Work Done
Calories become liable to a more flexible interpretation in assessments of their extra supply according to work done. Coal mining, for example, is often said to demand an extra 120 calories an hour, or one and a half times the basic needs of a fair-sized individual; but there must be coal miners and coal miners, even assuming an equal task. Some people do a job with minimum energy expenditure, only bending down when they have realized the absolute necessity of doing so.
They cut corners, lift a shovel with a foot rather than reach for it, and never squander their resources. As was said at an obesity conference, not only do some take less exercise but some exercise less energetically when taking it. A few fat girls were once filmed playing tennis, and even during singles, they were motionless for 60% of the time. A fat individual is often an expert at such maneuvers, thereby adding to his or her fatness.
Similarly, defying all the rules, some people eat like giants and remain like rakes; others eat like sparrows and expand like balloons. Also, people with large frames are more likely to grow heavier. As the British Medical Journal once put it: 'To him who hath, it seems, weight shall be given.' Fat men do need more food; not only do they have more to maintain, but they need more energy to transport themselves around, and yet they still tend to fatness more than the thin ones.
Explain A Few Exceptional Cases That Defy Your Explanation Above
Calories do count, although a book sold well by saying the opposite, but by no means is calorie theory reconciled to calorie practice. Suppose, for example, a man is eating the correct amount.
Suppose he is then permitted some minor indulgences, such as a banana with his breakfast, one bottle of beer and one more slice of bread with his lunch, a cup of lemonade and one piece of cake for tea, and then a bar of chocolate on the way home. These humble additions to his fare, not everyone's taste admittedly, nonetheless add up to 600 calories in that one day.
In theory, he would have to walk fast for over two hours, or row once from Putney to Mortlake, to burn up the extra calories. If he fails to do something of the sort and continues to consume the additional items, he will have put on 1 lb. ( ½ kg.) of fat by the end of a week. And to get rid of 1 lb. of fat means walking thirty-four miles.
However, despite the theory, people do often eat more than they should, they often take less exercise than they should, and yet they do stay reasonably constant in weight. There is no other way of acquiring calories except in food, and yet there do seem to be ways of disregarding calories without putting on fat or doing anything positive to counter their rapid intake. One wonders, for example, about the calorific content of feces from different people at different times: there must be great variation.
Nutritionists in general agreed that the former straightforwardness of calories tends to grow more complex year by year. An American, for example, has listed twenty-seven different types of obesity. He would also, one presumes, agree that there is more than one reason why some people eat too many calories and yet remain eternally thin, while others are perversely the other way about.
A baby and a young child both need much less food than an adult. However active the infant, he is having to move much less bulk about, and requires less energy to move his smaller frame from A to B.
By the age of ten or twelve a boy starts needing as much food as his father, by fourteen he probably needs a third as much again, and by eighteen halves as much again; the ages depend upon the timing of his growth spurt, and his actual size at any time, for it is his size and his work output which are most relevant. Growth itself is not very demanding of calories. The average growth rate of both boys and girls between eleven and sixteen is about 9 lbs. (4 kgs.) a year, requiring only 44 calories extra a day, allowing 4 calories per gram of protein.
Mankind is an increasingly idle being - his latest title is Homo sedentarius. Only a few centuries ago everything was done by muscle power. Now, this is no longer so, but there is still great variance in activity and consequently in fuel needs. To swim demands 550 calories an hour, to run 500, to saw wood 400, to work stone 330, to walk fast 240, to dance 240, to bicycle 175, to walk slowly 140, to sweep 100, to drive 60, to dress 50, to stand 40, to write 30, and to think demands none whatsoever.
These averages are wild averages, for some dance with the vigor of sawing wood, and some saw wood with the zest of a road sweeper. The brain does indeed cause no measurable increase in energy output, although muscle tension accompanying the anxieties of cerebral activity consumes energy on its separate account.
All in all, no one runs, dances, bicycles or thinks all day long, and minimum requirements become more uniform. Comparative estimates for sedentary, light, moderate, and heavy work have been assessed as requiring at least 2,500, 3,000, 3,500, and 4,000 calories a day. Should anyone, run, dance, or ride all day long his needs will be far greater; long bicycle races can burn up 10,000 calories in twenty-four hours, and even some lumbermen can regularly consume and use 8,000 calories a day.
For the most part, a twentieth-century man in advanced countries is being increasingly transported to work, increasingly sat down when he gets there, and increasingly in need of fewer than 3,000 calories, although he probably eats more than that and so is fatter than he should be.