Tobacco causes about 40,000 deaths per year in Spain from illnesses such as lung cancer, heart attacks, and coughs. It is forbidden to smoke in schools, hospitals, and other enclosed public spaces to protect non-smokers from secondhand smoke. Alcohol limits brain functions and can cause memory loss and heart disease. Drugs like cannabis can impair concentration, memory, and coordination and alter hormone development. Obesity, defined as excessive fat accumulation, affects over 1.6 billion people worldwide and is caused by diets high in calories and sugars with lack of physical activity. Obesity increases the risk of diseases like heart disease, diabetes, osteoarthritis, and some cancers.