Se observa una asociación inversa significativa entre la actividad física y la obesidad
Obesity, which in itself is a long-term disease, is at the same time a risk factor in the development of serious pathologies such as ischaemic heart disease, hypertension, hypercholesterolaemia and respiratory insufficiency.1 In developed countries, the prevalence of this disease has risen dramatically in recent decades and its presence is increasing in developing countries.2 One of the most worrying aspects of obesity is that it seriously impairs the quality of life and reduces life expectancy. Likewise, the treatment of obesity-related conditions has a huge economic impact to the public health system.1 Therefore, the obesity epidemic is a serious public health problem in many countries.
The large geographic variation in the prevalence of obesity between countries and within countries, including Spain, is a characteristic of the epidemic.3 In Europe, nearly half of the adult population is overweight or obese, although the figures are less dramatic than in the USA. Overall, in the central, eastern, and southern regions of Europe, prevalence rates are higher than in the western or northern regions. In particular, the prevalence of obesity in Spain is high,4 and according to the Organisation for Economic Co-operation and Development (OECD) report, its rate in the adult population is above the OECD average (15%) and is expected to increase by a further 7% during the period 2010–2020.5
Obesity is a multifactorial condition that usually results from a prolonged energy imbalance between the amount of calories consumed and the amount of calories expended. Previous studies have established different factors related to overweight or obesity, such as age, marital status, social class, smoking habits, alcohol consumption and habitat.1 Furthermore, social, technological and industrial changes in developed and developing societies have modified nutrition and lifestyle patterns among the population, particularly among adults. The changes in life habits have led to a significant increase of sedentary lifestyle. Some authors have suggested that decreasing levels of physical activity at work and at leisure-time are important factors contributing to the current obesity epidemic and its rapid distribution worldwide.6 However, although the relationship between low leisure-time activity and obesity has been widely studied, there is no consensus among the relationship between low physical activity at main activity and obesity.7
The objective of the present study is to analyze the relationship between two types of physical activity and the weight status in the Spanish population between 16 and 65 years old, using a multilevel model.