For a long time, we have been told that exercise is key to weight loss. If you don't have time to exercise, or can't, your excuse is built in.
Not so, says a recent international study. It comes down to knowing how many calories your body needs and eating that or less. Exercise can simply increase the calories you may ingest without gaining weight. Oddly, we knew this in 1908 but it seems to have been lost somewhere.
Researchers from Loyola University Health System and other centers compared African American women in metropolitan Chicago with women in rural Nigeria. On average, the Chicago women weighed 184 pounds and the Nigerian women weighed 127 pounds. They expected to find that the slimmer Nigerian women were more physically active but there was no significant difference between the two groups in the amount of calories burned during physical activity.
"Decreased physical activity may not be the primary driver of the obesity epidemic," said Loyola nutritionist Amy Luke, Ph.D., corresponding author of the study in the September 2008 issue of the journal Obesity. Luke is an associate professor in the Department of Preventive Medicine and Epidemiology at Loyola University Chicago Stritch School of Medicine.
Physical activity is defined as anything that gets your body moving. U.S. government guidelines say that each week, adults need at least 2 ½ hours of moderate aerobic activity (such as brisk walking) or 75 minutes of vigorous activity (such as jogging). Adults also should do muscle-strengthening activities, such as weight-lifting or sit-ups, at least twice a week.
Physical activity has many proven benefits. It strengthens bones and muscles, improves mental health and mood, lowers blood pressure, improves cholesterol levels and reduces the risk of cardiovascular disease, diabetes, breast cancer and colon cancer.
But Loyola research suggests that weight control might not be among the main benefits. People burn more calories when they exercise. But they compensate by eating more, said Richard Cooper, Ph.D., co-author of the study and chairman of the Department of Preventive Medicine and Epidemiology.
"We would love to say that physical activity has a positive effect on weight control, but that does not appear to be the case," Cooper said.
The recent study included 149 women from two rural Nigerian villages and 172 African American women from the west side of Chicago and suburban Maywood.
Adjusted for body size, the Chicago women burned an average of 760 calories per day in physical activity, while the Nigerian women burned 800 calories. This difference was not statistically significant.
Diet is a more likely explanation than physical activity expenditure for why Chicago women weigh more than Nigerian women, Luke said. She noted the Nigerian diet is high in fiber and carbohydrates and low in fat and animal protein. By contrast, the Chicago diet is 40 percent to 45 percent fat and high in processed foods.
Results of the new study are similar to those of a 2007 study of men and women in Jamaica. Researchers from Loyola and other centers found there was no association between weight gain and calories burned during physical activity.
"Evidence is beginning to accumulate that dietary intake may be more important than energy expenditure level," Luke said. "Weight loss is not likely to happen without dietary restraint."
Other centers involved in the study of Chicago and Nigerian women include University of Ibadan in Nigeria, Howard University, Johns Hopkins Bloomberg School of Public Health and University of Wisconsin.
Article: Kara E. Ebersole, Lara R. Dugas, Ramon A. Durazo-Arvizu, Adebowale A. Adeyemo, Bamidele O. Tayo, Olayemi O. Omotade, William R. Brieger, Dale A. Schoeller, Richard S. Cooper, Amy H. Luke,'Energy Expenditure and Adiposity in Nigerian and African-American Women',Obesity (2008) 16 9, 2148–2154. doi:10.1038/oby.2008.330
Comments
Drew (not verified) | 01/06/09 | 17:35 PM
I put it in the text above too. Usually readers don't have subscriptions to all of the paid journals so it isn't an issue .
Hank Campbell | 01/06/09 | 18:00 PM
This is a joke, right?
"Exercise can simply increase the calories you may ingest without gaining weight."
I'm sorry, but this has to be one of the silliness conclusions I've read in a while. The purpose of exercising to lose weight is to NOT increase your food intake. The simple fact that this statement indicates one can eat more, also means that if one doesn't increase their food intake then more calories will be expended resulting in weight loss.
One problem is the article's suggestion that weight loss occurs equally throughout the body based on diet alone. In truth, exercise will tend to raise the metabolism to continue burning calories for longer periods of time than the simple exercise period. In addition, it forces the body to conserve muscle mass instead of using it to obtain energy. This is precisely the problem that many dieters run into when they lose muscle mass and therefore drive their metabolism to lower levels, resulting in a more rapid weight gain when they return to normal.
The equation for weight has always been simple. Number of calories consumed must be equal to those expended. If there are too many consumed then weight is gained, and when more are expended then weight is lost. I have seen nothing in this article to suggest otherwise.
It is also important to note that bariatric surgery achieves results by simply forcing fewer calories to be consumed because the stomach can't hold more. However, exercise is a critical element of post-bariatric recovery since it becomes more important to preserve the muscle mass due to fewer calories being taken in.
""Evidence is beginning to accumulate that dietary intake may be more important than energy expenditure level,"
This statement makes no sense because it implies that there is a fundamental different between a food calorie and one expended during exercise.
Gerhard Adam | 01/06/09 | 20:07 PM
Approximately half of all children under the age of 12 are either obese are overweight. About twenty percent of children ages 2 to 5 years old are either obese are overweight. Worldwide, nearly one and a half billion people are either obese or overweight. In the United States, about one third of adults are either obese or overweight. It is now predicted that, for the first time in about 150 years, our life expectancy is suppose to decline.
Morbid obesity is defined as one who has a body mass index of 30 kg/m or greater, and this surgery, along with the three other types of surgery for morbid obesity, should be considered a last resort after all other methods to reduce the patient’s weight have chronically failed. Morbid obesity greatly affects the health of the patient in a very negative way. It has about 10 co-morbidities that can develop if the situation is not corrected. Some if not most of these co-morbidities are life-threatening.
One solution beneficial in many cases of morbid obesity if one’s obesity is not eventually controlled or corrected is what is known as gastric bypass surgery. This is a type of bariatric surgery that essentially reduces the volume of the human stomach in order to correct and treat morbid obesity by surgical re-construction of the stomach and small intestine. Patients for such surgeries are those with a BMI of greater than 40, or a BMI greater than 35 if the patient has comorbidities aside from obesity. This surgery should be considered for the severely obese when other treatment options have failed.
There are three surgical variations of gastric bypass surgery, and one is chosen by the surgeon based on their experience and success from the variation they will utilize. Generally, these surgeries are either gastric restrictive operations or malabsorptive operations. Over 200,000 gastric bypass surgeries are performed each year, and this surgery being performed continues to progress as a suitable option for the morbidly obese. There is evidence that this surgery is particularly beneficial for those obese patients that have non-insulin dependent Diabetes Mellitus as well.
So the surgery to correct morbid obesity greatly limits or prevents such co-morbidities associated with those who are obese. Two percent of those who undergo this surgery die as a result from about a half a dozen complications that could occur. However, the surgery reduces the overall mortality of the patient by 40 percent or so, yet this percentage is debatable due to conflicting clinical studies.
Age of the patient should be taken into consideration, as to whether or not the risks of this surgery outweigh any potential benefits for the patient who may have existing co-morbidities that have already caused physiological damage to the patient. Also what should be determined by the surgeon is the amount of safety, effectiveness, and rationale for a particular patient regarding those patients who are elderly, for example.
Many feel bariatric surgery such as this should be considered as a last resort when exercise and diet have failed for a great length of time.
If a person or a doctor is considering this type of surgery, there is a website dedicated to bariatric surgery, which is: www.asmbs.org,
Dan Abshear
________________________________________