With the increase of technology and transportation, people living in the 21st century have become less physically active compared to the people living in the 20th century. A study conducted by Kaiser Family Foundation in 2009 revealed that people between the ages of 8-18 spend an average of 7.5 hours a day on a cellphone (CBS News). With that much time spent on cellphones, the opportunity to do physical activity is shortened between school and homework. In 1969, 40% of children walked to school, whereas only 13% walked to school in 2000 (Harvard T.H Chan). According to Harvard School of Public Health, the amount of people driving to work increased by 20% between 1690 and 2000 and the amount of people walking or using public transportation decreased As the level of physical activity in our country began to decrease, the food portions consumed began to increase. Just between 1987 and 2000, caloric intake increased by a whopping 40%. During those same years, the plate sizes at restaurants increased from 10.5 inches to 12.5 inches (Spaccarotella, Kim). Due to this, people became accustomed to eating big portions. Before the modern technological era, families would go out to the park, have picnics, and play sports. Now, families opt out for McDonalds burgers and Netflix. There is no …show more content…
It is a fast and easy system that uses a person’s weight and height to assess an approximation of their body fat. A BMI of 18.5> is considered underweight, 18.5-24.9 is normal, 25-29.9 is overweight, and 30< is obese. Although it is very accurate, it is not a direct measurement of body fat. A persons weight includes both muscle and body fat. Thus meaning that a body builder could have a high BMI, but not be overweight. Physicians use other tests such as skinfold testing, hydrostatic weight, and bioelectrical impedance to determine body fat. The skinfold tests are based on the fact that most of the body fat is subcutaneous, meaning it is on the surface of the body. Calipers are used in different locations of the body to determine thickness. Hydrostatic weighting uses a tank to determine a persons underwater weight, which can then calculate the body density and percentage of body fat (Shape Up America!). It uses the concept of Archimedes principle which says that an object more dense than the water will float and and object less dense than the water will sink. Lastly, the bioelectrical impedance analysis uses electricity to measure the resistance of electrical current flow between points. Fat is a good insulator and water is a good conductor. A person whose body has more muscle can hold more water. This means that the less fat in the body there