The recent edition of „Postępy Nauk Medycznych” („Progress in Medical Sciences”) presents various aspects of obesity. Currently, obesity constitutes a serious public health problem in many countries and Poland is not an exception in this respect. In Poland, 20% of adults and 3-4% of children are obese and a considerable number of Poles are overweight. Excessive body weight is also a problem whose scale has been increasing in recent years. It is discussed in this edition’s introductory article by Professor M. Jarosz and E. Rychlik, PhD. The article presents the initiatives taken to counteract obesity both in Poland and on the international forum. Activities in Poland are primarily taken under the National Programme for the Prevention of Overweight, Obesity and Non-Communicable Diseases through Diet and Improved Physical Activity – POL-HEALTH.

The initial original paper (by R. Wierzejska, PhD et al.) emphasises the significance of correct body weight of women in reproductive age. Overweight or obesity before pregnancy poses the risk of too high weight gain during pregnancy and development of macrosomia in a child.

The paper on research on body weight and diet of children from primary schools in Warsaw (by K. Wolnicka, PhD and J. Jaczewska-Schuetz, MSc) claims that the development of obesity results from an inappropriate dietary pattern, such as a low number of meals, little fruit and vegetables in the diet and drinking sweetened beverages.

The diet of elderly women suffering from obesity is also frequently inappropriate (as concluded by the paper by Professor J. Charzewska et al.). Their diet has usually high energy content, particularly from fat, which affects their lipid indexes to a significant extent. Obesity in seniors may result in difficulties handling everyday physical activity, as confirmed by the findings contained in the paper on the lifestyle of elderly women (by E. Chabros, PhD et al.).

One of the major complications resulting from obesity is atherosclerosis. The risk of its development is higher inter alia due to more frequent disturbances of fibrinolytic activity in the obese, as described by the paper by A. Jarosz, PhD and Professor G. Nowicka. Obesity is also connected with the risk of developing the gastro-oesophageal reflux disease, as confirmed by the results of research presented in the paper by Professor M. Jarosz and A. Taraszewska, MSc.

In research on obesity and related complications more attention is devoted to genetic factors. This stream of research includes the paper (by M. Włodarczyk, MSc et al.) which evaluates inflammatory markers in metabolic syndrome patients. It was established that the concentrations of fibrinogen, C-reactive protein (CRP) and adhesion molecules were higher in A-allele carriers as compared to GG homozygote for fibrinogen gene.

Genetic factors may play a role in 25-40% of obesity cases, as highlighted by M. Białkowska, PhD in her article on aetiological factors of obesity. Genetic factors influence inter alia appetite, basal metabolic rate, neuropeptide and hormone secretion, adipocyte functions and spontaneous physical activity. Apart from inappropriate diet and low physical activity, sleep disorders are environmental factors conducive to obesity. There are also recent reports on the significance of the viral infection developing obesity.

Another paper (by Professor Jarosz et al.) discusses the significance of environmental factors in overweight and obesity development in children and young people. The paper lists inappropriate dietary patterns development of children and their parents, missing meals, availability of fast food, sweets and sweetened beverages, as well as low physical activity, devoting much time to TV and computer, too short sleep.

Obesity is accompanied by higher mortality, mainly due to cardiovascular diseases, diabetes and malignant cancers. The paper devoted to obesity influence on health (by Professor W.B. Szostak et al.) discusses the results of recently published research showing that in the obese, the increase in mortality is proportionate to their relative body weight. It also emphasises that health consequences are more frequent in people with abdominal obesity, as opposed to gynoid obesity.

The basis of overweight and obesity treatment is to reduce the energy content in the diet and increase energy expenditure. As the recommendations must be observed for an extended period of time, many patients find the process difficult. Therefore, they try new slimming diets (such as the protein diet or the low-carbohydrate diet), but that may have a detrimental effect on their health, as discussed by the paper by Professor L. Kłosiewicz-Latoszek and Professor W.B. Szostak.

Diet modification and improved physical activity are the basis for obesity treatment also during pharmacotherapy and when surgical methods are involved, as highlighted in paper by W. Respondek PhD concerning the obesity treatment principles.

The papers included in this edition of „Postępy Nauk Medycznych” („Progress in Medical Sciences”) illustrate that obesity is a very serious health problem and counteracting it ma be very difficult. Only integrated and consistent activities in the area can produce expected results.