The growth in body weight of Americans over the past 30 years can be explained solely by an increase in calorie intake. The role of factors influencing body weight allows to evaluate the study presented on Friday at the European Congress on excess weight. The work, designed to clarify the mechanisms of the "obesity epidemic" that is unfolding in the US since the seventies of the last century, was held at the Australian Deakin University under the leadership of Professor Boyd Swinburn, head of the Population Health Department and director of the WHO Collaborating Center for Overweight prevention.

The need for such a study has arisen because of the uncertainty to what extent the body weight of an average American has grown over the past decades as a result of overeating, and in what way - because of reduced physical activity. It is clear that to reduce body weight it is necessary to eat less and exercise more, but from the point of view of public health it is necessary to establish reliably on which of the factors the emphasis should be placed first.

At the first stage of the work, scientists have established with the greatest accuracy how many calories a person burns in real life. This study was conducted in 1399 adults and 963 children. Having established the exact energy consumption, Swinburne's group was able to calculate how much an adult needs to have to maintain their weight, and how much to a child, for normal development.

After this, a calculation was made of the real consumption of food by all Americans. For this purpose, information was used on the supply of products throughout the country (the amount of food produced and imported minus the amount exported, thrown into garbage and used for animals and for other purposes) from the seventies to the 2000th years.

Based on the data obtained, Swinburne suggested what would be an increase in the body weight of the average American if the food was the only determining factor. Then these data were compared with the results of representative national studies that documented the real increase in the average body weight in the period under study. Forecast Swinburne provided for an increase in body weight by 10.8 kilograms. In reality, the average American is now 8.6 kilograms heavier than at the time of Richard Nixon.

According to the researchers, the difference between the prognosis and statistical data demonstrates the role of physical activity, and in general, weight gain can only be explained by overeating. To return to the weight of the seventies, the average American needs to additionally burn 350 kilocalories to children and 500 kilocalories to adults. For this, it is enough for children to make daily walks of 150 minutes for children and 110 minutes for adults.

In his work, Swinburn concludes that in the fight against excess weight, Americans should pay the most attention to reducing food intake, rather than physical exercise.

Sportzal. Com.