How Excess Weight Affects Human Health

It is essential to distinguish between the condition of being overweight and the clinical diagnosis of obesity, as their implications for health and medical classification differ substantially. While excess weight serves as a risk factor for the progression to obesity, it does not constitute a disease in itself. According to the World Health Organization’s established criteria, obesity is identified when an individual’s body mass index (BMI) exceeds the threshold of 30 kilograms per square meter of body surface area. However, despite its widespread adoption as a primary screening tool, BMI is not an infallible diagnostic measure. Its most significant limitation lies in its failure to account for the distinction between fat mass and lean body mass—particularly skeletal muscle. Consequently, individuals with highly developed musculature (e.g., strength athletes or bodybuilders) may be misclassified as obese, even if their percentage of body fat remains low. Notwithstanding these exceptions, BMI remains the most frequently employed metric in epidemiological research due to its simplicity and reproducibility. Empirical evidence confirms a robust correlation between elevated BMI values and increased adiposity (Achamrah et al., 2018). Alternative assessment methods, such as bioelectrical impedance analysis, dual-energy X-ray absorptiometry, or waist circumference measurement, while more precise, necessitate specialized equipment and are less feasible for large-scale population studies. In clinical settings, these techniques are typically reserved for detailed diagnostic evaluations or the monitoring of therapeutic interventions.

A substantial body of scientific evidence confirms that excessive body weight represents a critical public health challenge, substantially elevating the prevalence of numerous non-communicable diseases that disproportionately affect industrialized societies. Empirical data consistently demonstrate that individuals with a body mass index (BMI) exceeding healthy thresholds exhibit a markedly higher susceptibility to metabolic disorders, cardiovascular diseases, and malignant neoplasms. Notably, however, certain exceptions to this pattern have been documented: research conducted by M. E. Kroll et al. (2016) reveals that conditions such as osteoporosis and hemorrhagic stroke occur with reduced frequency among obese populations compared to the general demographic. Nevertheless, these isolated benefits are vastly outweighed by the extensive spectrum of adverse health outcomes associated with obesity. Cumulative evidence from large-scale cohort studies and systematic reviews indicates that overweight and obesity significantly amplify the risk of developing various cancers—particularly those affecting the breast, ovaries, kidneys, and pancreas—while simultaneously disrupting endocrine balance in ways that compromise fertility in both sexes. Additional somatic complications encompass accelerated degenerative joint diseases, major depressive episodes, recurrent gout attacks, progressive renal failure, and insulin resistance culminating in type 2 diabetes mellitus. Furthermore, obese individuals face an elevated likelihood of experiencing coronary artery disease and ischemic stroke. In the context of the COVID-19 pandemic, findings published by F. Gao’s team (2020) established a robust correlation between obesity and increased severity of infection, prolonged recovery periods, and a higher incidence of extrapulmonary complications.

Prolonged exposure to stress-inducing factors—ubiquitous in contemporary society—may play a pivotal role in the pathogenesis of overweight and obesity. Individual coping mechanisms for emotional tension frequently involve compensatory eating behaviors, wherein food consumption serves as an emotional regulator. This phenomenon, commonly referred to as "stress eating," arises from the profound interplay between the nervous system and appetite-control mechanisms. Appetite—defined as the subjective desire to consume specific foods—is intrinsically linked to psychological states, rendering individuals under chronic stress particularly susceptible to using food as a means of alleviating negative emotions. In modern contexts, food consumption has transcended its primary physiological function of supplying essential nutrients. Meals have evolved into vehicles for multidimensional psychological needs, including: (1) affective expression through gifting symbolically meaningful products (e.g., sweets as tokens of care); (2) self-actualization, evidenced by meal preparation for social groups (family, friends); (3) the need for stability, manifested in ritualized eating schedules; (4) fulfillment of the need for social recognition through the selection of prestige-associated foods; (5) interpersonal bonding, where communal dining serves a communicative function. While these cultural dimensions of eating are inherently neutral, under conditions of chronic stress, they may contribute to disordered eating patterns leading to excessive weight gain (Juruć & Wierusz-Wysocka, 2011; Makara-Studzińska et al., 2007).

Extensive scientific evidence confirms that excess body weight constitutes a significant risk factor for the onset and progression of numerous diseases with diverse etiologies. Notably, even individuals maintaining a normal weight but adhering to unhealthy lifestyle patterns—characterized by poor nutritional habits or physical inactivity—are susceptible to comparable adverse health outcomes. In contemporary society, the role of food extends far beyond its primary function of supplying the energy required for maintaining physiological homeostasis; it also fulfills a critical regulatory function within the emotional and psychological domains. Of particular concern is the observation that chronic stress—a phenomenon increasingly pervasive in modern populations—substantially impedes the maintenance of optimal body weight by promoting compensatory behaviors such as "emotional eating." This pattern leads to a consistent excess of daily caloric intake, thereby fostering the long-term development of obesity. It is imperative to emphasize that reducing the issue of overweight solely to aesthetic or morphological considerations represents an oversimplification with serious repercussions. Obesity is a multifactorial condition whose consequences span both somatic and psychological dimensions. Consequently, the adoption of comprehensive preventive strategies—encompassing regular, individually tailored physical activity alongside a rationally balanced diet—is essential for preserving health and functional capacity throughout one’s lifespan.