Obesity

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Running Head: Diet and Obesity

Diet and Obesity: The Effect on Human Factors Engineering

Emersonn C. Cabatu

Embry-Riddle Aeronautical University

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Abstract

It seems that in today's society faster, better, cheaper is the moniker for our way of life. That some is ok but more is better. In the realm of diet more is not necessarily better and that some can actually do more harm than good. This paper seeks to explore and explain some of the consequences that Human Factors Engineers must take into account when designing products for the marketplace when factoring the disturbing trend of obesity.

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The human body is an incredible machine capable of performing physical and mental tasks not common to the animal kingdom. But what is common to all organisms is the need for fuel to drive these systems either through production or consumption. In our case is it consumption. A homeostasis must be maintained and the lifestyle choices that we make dictate how we perform.

We are what we eat

Too much of one type of food consumed in a day can adversely affect human performance, especially if sleepiness or fatigue is induced. Too little food or an irregular schedule can induce irritability and decreased endurance. In addition dietary choices have been linked to many health related diseases such as heart disease, high blood pressure, and most prevalent in today's society, diabetes.

How do we begin to explore ones dietary needs? Food is often a source of considerable pleasure. Chocolate often soothes, many can not function until they have their first cup of coffee, while others need to satisfy that 3 mile itch to run prior to starting their day in a search for that "runner's high." But what truly drives what we eat is the influence the four senses (taste, touch, smell, and sight) on the enjoyment of eating is directly related to an individual's expectations based on childhood experiences. Taste expectations are learned. Everyone has had the experience of tasting a perfectly cooked steak or perhaps the first experience of tasting an extremely sour lemon. These learned events guide our choices as to what to eat based on how one wishes to satisfy their hunger.

To classify all people as having the same dietary needs is unfair. Genetics and physical activity play a significant role in defining how a body metabolizes food. First and foremost though is the need to have good eating habits. The US Surgeon General in various publications and commercials has often stated the need to eat a variety of different foods, maintenance of

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desirable weight (or is weight really how one should be judges?), eat foods high in fiber, and avoiding over consumption of sugars and fats.

Anyone who has seen the movie "Supersize Me", or even heard of it, can easily relate to how an increase of fat intake can adversely affect one's health. There are many various types of fats to include free fatty acids, gylcerols, cholesterol, and large fat molecules in the form of saturated, unsaturated, and poly-unsaturated fats. None the less fats are stored in body tissue. The accumulation of fat is a result of the input/output imbalance resulting from the high intake of calories but low use of those calories taken in.

There are many factors to consider how many calories a body needs per day. It is different for every person but is mostly dependent on two variables: weight and amount of physical activity. The basil metabolic rate is the amount of calories a body needs to function at rest and the Harris-Benedict formula gives the most accurate measurement.

Adult male: 66 + (6.3 x body weight in lbs.) + (12.9 x height in inches) - (6.8 x age in years)

Adult female: 655 + (4.3 x weight in lbs.) + (4.7 x height in inches) - (4.7 x age in years)

Physical activity is the second variable and simply put the more physically active an individual is the more the body burns either lessening the imbalance or shifting the imbalance where more calories are being burned than taken in and loss of weight occurs.

Am I Fat?

How much a person weighs has been a standard on judging how one looks, feels, and the overall health of a person. Scientific links have been made between obesity and many health related illnesses. In a recent report in the American Journal of Preventive Medicine, Americans gained an average of 10 pounds per person in the 1990s and that the National Center for Health Statistics state that Americans are 25 pounds heavier today than they were in 1960. Previously weight had been the determining factor on indicating if a person is obese but the measurement of

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a person's Body Mass Index (BMI) has gained popularity in determining if one is overnourished. The US Department of Health and Human services calculates BMI with the following formula:

BMI = ( Weight in Pounds

(Height in inches) x (Height in inches) ) x 703

For example, a person who weighs 220 pounds and is 6 feet 3 inches tall has a BMI of 27.5.

( 220 lbs.

(75 inches) x (75 inches) ) x 703 = 27.5

What does this all mean? Am I normal? The following table is an excerpt from the same report.

BMI Weight Status

Below 18.5 Underweight

18.5 - 24.9 Normal

25.0 - 29.9 Overweight

30.0 and Above Obese

The US Air Force has also taken a stance to follow these guidelines. In July 2005 the Air Force switched from solely using the waist circumference for determining a person's physical stature and moved to using the BMI.

BMI is not the definitive answer to the