Navigation Links
Increased food intake alone explains the increase in body weight in the United States
Date:5/8/2009

Amsterdam, the Netherlands: New research that uses an innovative approach to study, for the first time, the relative contributions of food and exercise habits to the development of the obesity epidemic has concluded that the rise in obesity in the United States since the 1970s was virtually all due to increased energy intake.

How much of the obesity epidemic has been caused by excess calorie intake and how much by reductions in physical activity has been long debated and while experts agree that making it easier for people to eat less and exercise more are both important for combating it, they debate where the public health focus should be.

A study presented on Friday at the European Congress on Obesity is the first to examine the question of the proportional contributions to the obesity epidemic by combining metabolic relationships, the laws of thermodynamics, epidemiological data and agricultural data.

"There have been a lot of assumptions that both reduced physical activity and increased energy intake have been major drivers of the obesity epidemic. Until now, nobody has proposed how to quantify their relative contributions to the rise in obesity since the 1970s. This study demonstrates that the weight gain in the American population seems to be virtually all explained by eating more calories. It appears that changes in physical activity played a minimal role," said the study's leader, Professor Boyd Swinburn, chair of population health and director of the World Health Organization Collaborating Centre for Obesity Prevention at Deakin University in Australia.

The scientists started by testing 1,399 adults and 963 children to determine how many calories their bodies burn in total under free-living conditions. The test is the most accurate measure of total calorie burning in real-life situations.

Once they had determined each person's calorie burning rate, Swinburn and his colleagues were able to calculate how much adults needed to eat in order to maintain a stable weight and how much children needed to eat in order to maintain a normal growth curve.

They then worked out how much Americans were actually eating, using national food supply data (the amount of food produced and imported, minus the amount exported, thrown away and used for animals or other non-human uses) from the 1970s and the early 2000s.

The researchers used their findings to predict how much weight they would expect Americans to have gained over the 30-year period studied if food intake were the only influence. They used data from a nationally representative survey (NHANES) that recorded the weight of Americans in the 1970s and early 2000s to determine the actual weight gain over that period.

"If the actual weight increase was the same as what we predicted, that meant that food intake was virtually entirely responsible. If it wasn't, that meant changes in physical activity also played a role," Swinburn said. "If the actual weight gain was higher than predicted, that would suggest that a decrease in physical activity played a role."

The researchers found that in children, the predicted and actual weight increase matched exactly, indicating that the increases in energy intake alone over the 30 years studied could explain the weight increase.

"For adults, we predicted that they would be 10.8 kg heavier, but in fact they were 8.6 kg heavier. That suggests that excess food intake still explains the weight gain, but that there may have been increases in physical activity over the 30 years that have blunted what would otherwise have been a higher weight gain," Swinburn said.

"To return to the average weights of the 1970s, we would need to reverse the increased food intake of about 350 calories a day for children (about one can of fizzy drink and a small portion of French fries) and 500 calories a day for adults (about one large hamburger)," Swinburn said. "Alternatively, we could achieve similar results by increasing physical activity by about 150 minutes a day of extra walking for children and 110 minutes for adults, but realistically, although a combination of both is needed, the focus would have to be on reducing calorie intake."

He emphasized that physical activity should not be ignored as a contributor to reducing obesity and should continue to be promoted because of its many other benefits, but that expectations regarding what can be achieved with exercise need to be lowered and public health policy shifted more toward encouraging people to eat less.


'/>"/>

Contact: Emma Ross
rosswrite@mac.com
31-020-544-4125
European Association for the Study of Obesity
Source:Eurekalert

Related medicine news :

1. National Survey: Parents Report Increased Awareness of Risks of Teen Prescription Drug Abuse, But Preventative Action Lags
2. In-Home Caregivers Standing by Nationwide to Support Increased Need Due to Swine Flu
3. New Study Indicates Changes in Cigarette Design Have Increased Lung Cancer Risk and Tobacco Regulation Can Greatly Reduce Lung Cancer
4. Safety Product Company Sees Increased Inquiries Resulting from H1N1 Flu (Swine Flu)
5. Data Show Dutasteride Reduces Prostate Cancer Diagnosis in Men With Increased Risk
6. Wyeths CONBRIZA Approved in the European Union for Treatment of Postmenopausal Osteoporosis in Women at Increased Risk of Fracture
7. Hypertension, diabetes and increased carotid artery wall thickness means increased risk of stroke
8. PLUS Diagnostics Opens West Coast Laboratory to Support Increased Demand for Anatomic Pathology Services
9. New study finds continued abstinence is key to increased survival from alcohol-related liver disease
10. Nationwide Foundation Donates $1.7 Million to American Red Cross for Disaster Preparedness and Response and Increased Blood Collections
11. Study suggests that trouble sleeping leads to increased ratings of pain in cancer patients
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating in cancer care, and ... in the eye of the beholder, according to experts who offered insights and commentary ... of Managed Care. For the full issue, click here . , For the ...
(Date:6/26/2016)... Lake Orion, Clarkston, Michigan (PRWEB) , ... June ... ... direction with respect to fertility once they have been diagnosed with endometriosis. These ... tolerable intercourse but they also require a comprehensive approach that can help for ...
(Date:6/25/2016)... ... 2016 , ... First Choice Emergency Room , the largest network of ... Medical Director of its new Mesquite-Samuell Farm facility. , “We are pleased to ... said Dr. James M. Muzzarelli, Executive Medical Director of First Choice Emergency Room. ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... A recent ... that most people are unfamiliar with. The article goes on to state that individuals ... also many of these less common operations such as calf and cheek reduction. The ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Global law firm ... 2016 Legal Elite. The attorneys chosen by their peers for this recognition are considered ... Seven Greenberg Traurig Shareholders received special honors as members of this year’s Legal Elite ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... INDIANAPOLIS , June 23, 2016 Roche ... received 510(k) clearance for its Elecsys BRAHMS PCT (procalcitonin) ... severe sepsis or septic shock. With this clearance, Roche ... provide a fully integrated solution for sepsis risk assessment ... associated with bacterial infection and PCT levels in blood ...
(Date:6/23/2016)... VIEW, Calif. , June 23, 2016 ... a.m. CST on Thursday, July 7, 2016 , , , ... kayla.belcher@frost.com ) , , , , EXPERT PANELISTS:  , ... Nitin Naik; Senior Industry Analyst, Christi Bird; Senior Industry Analyst, Divyaa ... The global pharmaceutical industry is witnessing an ...
(Date:6/23/2016)... The vast majority of dialysis patients currently ... are usually 3 times a week, with treatment times ... time, equipment preparation and wait time.  This regimen can ... patients who are elderly and frail.  Many elderly dialysis ... centers for some duration of time. Residents ...
Breaking Medicine Technology: