Fast Food and Obesity How does fast food affect obesity? By Christie Demps
Fast Paced Lives • There is a high demand for speedy services…high-speed internet, fast drying nail polish, fast computers, digital cameras, etc. • Fast food
What I Will Discuss • Overview of obesity. What is it? It’s Prevalence in the U.S. • Overview of fast food. What is it? Why do we consume so much as Americans? What is the problem with it? • A study discussing the energy density of fast food and how this affects weight gain leading to obesity. • Why is studying the affects of fast food on obesity important? Changes that have begun to be made and can be made in the future to help alleviate the problem.
What is Obesity? • The condition of being obese; increased body weight caused by excessive accumulation of fat. (BMI>30)
Prevalence of Obesity in the U.S. • According to the National Center for Health Statistics, the Prevalence of Overweight and Obesity Among Adults in the United States has doubled between 1976 and 2002 (15%-31%).
What is Fast Food? • Low in nutrients. High in fat, calories, sodium, and/or sugar • Easy consumption
Why do we eat fast food? • Taste • Prices for fast food are significantly cheaper than fresh food. • The Media: TV-Commercials are filled with advertisements promoting fast food. Newspapers- Contain coupons for sales on fast food. • Convenience
Why is studying fast food and obesity important? • We as Americans consume so much. If fast food does have an affect on obesity, then the consumption of it can cause us to have many health related problems such as heart disease.
The Study • MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, UK. • Reviewed a series of studies to demonstrate that the energy density of food is a key determinant of energy intake.
The Study Continued… • Collected food composition information from leading fast food chains • Energy density avg. 1100 kJ /100 g -1 British foods- 525 kJ/ 100 g -1 African foods- 450 kJ/ 100 g -1 • 3 Experiments altering the amount of fat each group consumes
The Data • 3 Experiments • Exp.1- 7 day High fat diet • Exp. 2.- 7 day Low fat diet • Exp. 3- Energy density held constant
The Results • Exp. 1 and 2- Spontaneously ingested more energy on the diet of high energy density and less than that on the low energy density. (High-fat Hyperphagia) • Exp. 1- Gained 65g fat/day • Exp. 2- Lost weight * no physiological or behavioral compensation by the end of day 7 on either • Exp. 3- High fat hyperphagia was abolished
What does all of this tell us? • In summary, physiological experiments illustrate the potency by which energy-dense diets can undermine the normal processes of appetite regulation in humans. This failure of physiological regulation causes an accidental positive energy balance.
The Future… Suggestions for improvement: • to provide and promote a wider range of healthy options with low energy density • to take steps to reduce the energy density of menu items across the board (usually achievable by reducing the fat content); • to provide clear listings of nutritional composition (especially energy and fat) at point-of-purchase and on packaging; • to stop encouraging inappropriately large portion sizes through advertising, manipulative price structures and pressure selling of additional or larger menu items.
References • U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICESCenters for Disease Control and PreventionNational Center for Health Statistics http://www.cdc.gov/nchs/products/pubs/pubd/hestats/obese/obse99.htm • Fast foods, energy density and obesity: a possible mechanistic link. A. M. Prentice1 and S. A. Jebb2. Obesity ReviewsVolume 4 Issue 4 Page 187 - November 2003