IASO Press Release
How big is the energy gap in obesity?
The oversimplification of the
“energy-in/energy out” equation is generating a fundamental public
misunderstanding of the challenges of obesity, an eminent expert has warned at
the International Congress on Obesity in
Professor Claude Bouchard, the outgoing president of IASO, the obesity research community’s global organization, described the concept of serious weight gain being the result of just a small imbalance between energy intake and expenditure of as little as 15 kcals was defective.
“This idea that obesity is the result of a tiny energy surplus
accumulated over the years is quite misleading,” added Professor Bouchard, a
leading geneticist, and Executive Director of
“I’m concerned when I hear those working in the health field and even some scientists coming out with this kind of notion, which is fundamentally flawed. Clearly if it truly were that simple, we wouldn’t have the massive problem we are facing all over the world.”
The small surplus proposition is based on the assumption that calories are simply converted into fat stores at no energy cost and with no resulting changes in an individual’s energy requirements.
But Prof Bouchard said that not all surplus calories are stored with about a third are used up in the process of converting excess energy to fat stores. The imbalance in the early stages of weight gain may be very small compared to the much larger surplus involved in weight gain at the later stages of obesity.
Overweight and obese people actually have a normal metabolism, contrary to popular beliefs, but their basic resting energy requirements increase as they gain weight. In addition, obese people need to burn more energy to move around.
“This situation would be typical of someone who has become moderately overweight. In the case of a greater weight gain, as in frank obesity, the energy gap is much more substantial,” said Professor Bouchard.
Someone at an end point with an excess weight gain of 30 kg would have an imbalance of about 600 to 700 calories per day. An excess weight of 40 kg and more – not untypical in the one third of the adult population who are obese in the USA, - can easily translate in an energy gap of 1,000 calories per day to sustain the new body mass in comparison the prior normal weight level.
“This indicates that much larger numbers of calories are consumed compared to the situation when the same individual was normal weight,” he added.
One critical lesson, he warned, was that the narrowing the energy gap was likely to be much more successful when both energy intake and energy expenditure are addressed - cutting down food intake, increasing physical activity, and decreasing time spent in sedentary inactivity . This can be achieved much more easily at the earlier stage of weight gain, before serious levels of overweight are attained when the energy gap or surplus is still relatively small.
“It is important that we have a much clearer understanding of this issue, which is not as complex as it sounds, and reinforces the message that prevention is much better than cure. So we need to focus on those who are shifting from normal weight into the overweight category to attack that smaller weight gain before it becomes much harder to overcome,” Professor Bouchard concluded.
Professor
Claude Bouchard will be available to discuss this analysis at the International
Congress on Obesity Media Centre on Thursday September 7 at 12.30 pm. (
For further information please contact:
ICO media
team/Health Communications
Felicity Moffatt + 61 418 677 701
Kate McEvoy + 61 424 649 148
International Association for the Study of Obesity
Mobile
numbers:
Note to editors:
According to US Department of Agriculture’s Economic Research Service the food supply provides 3,800 kcalories per person per day - 500 kcalories above the 1970 level and 800 kcalories above the level half a century ago, when physical activity levels were much higher. In 2000 at just under 2,700 calories per person per day. ERS data suggest that average daily calorie intake increased by 24.5 percent, or about 530 calories, between 1970 and 2000.
In 2000 Americans consumed 20 percent more fruit and vegetables than did their counterparts in the 1970s, but they also consumed more sugary foods and beverages. Per capita consumption of sugar and sweeteners such as high-fructose corn syrup increased 39 percent, between 1950s and 2000. The average American now consumes about 152 pounds (69 kg) of caloric sweeteners. After allowing for wastage, that amounts to more an average intake of about 32 teaspoons of added sugars per person per day.
– Source:
USDA Agriculture Fact Book 2001-2002 CHAPTER 2 Profiling Food Consumption in
http://www.usda.gov/factbook/chapter2.pdf
Adult obesity
prevalence more than doubled in the
|
|
NHANES II |
NHANES III |
NHANES |
NHANES |
NHANES |
|
Overweight
or obese (BMI greater than or equal to 25.0) |
47.0 |
55.9 |
64.5 |
65.7 |
66.2 |
|
Obese
(BMI greater than or equal to 30.0) |
15.0 |
23.2 |
30.9 |
31.3 |
32.9 |
Prevalence of overweight among children and adolescents ages 6-19 years, for selected years
1963-65 through 1999-2002
|
Age
(years)1 |
NHANES |
NHANES |
NHANES |
NHANES |
NHANES |
NHANES |
NHANES |
|
6-11 |
4.2 |
4 |
6.5 |
11.3 |
15.1 |
16.3 |
18.8 |
|
12-19 |
4.6 |
6.1 |
5 |
10.5 |
14.8 |
16.7 |
17.4 |
