outlook: OBESITY epidemic

Debunking Nutrition Myths

People trying to eat healthfully may be reading and passing on a lot of information regarding nutrition; not all of it is necessarily correct. At the American College of Sports Medicine?s 11th Annual Health and Fitness Summit and Exposition in Dallas, Tex, Wendy Repovich, PhD, FACSM, and Janet Peterson, DrPH, FACSM, addressed some common nutrition myths:

• Carbs make you fat. Whereas cutting carbs from your diet may result in short-term weight loss, this is a result of water loss from reduced carbohydrate stores. Eating carbs in moderation will not cause weight gain; on the other hand, cutting them out completely can cause lethargy and thus impair one?s ability to exercise.
• Eating eggs will result in high cholesterol. Although it is true that egg yolks have the most concentrated amount of cholesterol of any food, the yolks do not contain enough cholesterol to pose a threat if eggs are eaten in moderation. In fact, some studies have shown that consuming 1 egg per day will not affect cholesterol levels and that eggs are a good source of nutrients.
• Everyone needs to take vitamins. The fact is that supplements are not necessary if one?s diet includes a variety of fruits, vegetables, and whole grains, as well as some low-fat dairy and protein, and the appropriate amount of calories for one?s lifestyle. Because most Americans do not do this, a multivi-tamin is a good idea, especially for pregnant women or those who have nutritional disorders.
• Eating fiber is a bad idea if you have irritable bowel syndrome (IBS). It is important to remember that fiber comes in 2 forms: soluble and insoluble. Insoluble fiber (eg, seeds, unpeeled apples and tomatoes, broccoli) can cause problems for IBS sufferers. Soluble fiber (eg, most grains, nuts, carrots) is more easily absorbed into the body and prevents constipation. For more information on soluble versus insoluble fiber, visit www.healthcastle. com/fiber-solubleinsoluble.shtml.
• Foods with a low glycemic index can help prevent type 2 diabetes. Diabetes is not caused by high levels of glucose but rather by the body?s resistance to insulin.Foods that are high on the glycemic index will cause glucose levels to rise dramatically?this is an indicator of diabetes, not the cause.

Asthma Rates Increase with Obesity

A recent study found that if the two thirds of Americans who are overweight or obese achieved a significant weight loss, then the number of new asthma cases in US adults ?might fall by as much as 250,000 per year.? These data come from a report by E. Rand Sutherland, MD, MPH, and David A. Beuther, MD, of the National Jewish Medical and Research Center in Denver, Colo. They and their research team studied the relationship between body mass index (BMI) categories and the occurrence of asthma by pooling data from 7 studies encompassing 333,102 adults. Adults who were overweight or obese were 50% more likely to be diagnosed with asthma, compared with normal-weight adults. In fact, a higher BMI level meant a greater likelihood of developing asthma. The results were published in the April 2007 issue of the American Journal of Respiratory and Critical Care Medicine.

How Teens Achieve Successful Weight Loss

According to a University of Minnesota Medical School study, the following lifestyle alterations have been identified as factors resulting in successful weight loss among teenagers:

• Weight training and strengthening exercises for teenage girls
• Less time in front of the TV
• Participation in more moderate-to-vigorous physical activity. Teenage girls who lost weight logged in an average of 7.6 hours of physical activity per week, while teenage boys who lost weight got in an average of 11.7 hours of exercise per week.

Lead author Kerri Boutelle, PhD, remarked, ?This study gives researchers, clinicians, and parents a better understanding that teens can lose weight, and what behaviors are associated with success.?

Atkins Wins Battle of the Diets

A recent study randomly assigned 311 overweight/obese, nondiabetic, premenopausal women to 1 of 4 diets: the very-low-carbohydrate Atkins diet; the moderately low-carb Zone diet; the high-carb Ornish diet; or the low-fat, high-carb LEARN diet, which is based on national dietary guidelines. At 12 months, the Atkins diet came out on top with a 10.4-lb average weight loss (Figure).

Ms. Farley is a freelance medical writer based in Wakefield, RI.