Obesity is a medical condition that occurs when the body stores enough excess fat to pose a health risk to the individual. Most people recognize the dangers inherent with excessive body weight, but nutritionists are still debating the exact causes of obesity. The common explanation is that obesity results from too much food intake and too little energy expenditure. A small number of cases have been demonstrably shown to result from hormone imbalance caused by genetics, mental illness, or medical anomalies. Other contributors that are associated with higher body weight include lack of sleep, environmental pollutants, increased medication, ethnicity, and age.
Since 1970, the average calorie consumption in the United States has increased by 335 calories per day for women and 168 calories per day for men. The majority of this extra food energy comes in the form of increased carbohydrate consumption, namely sweetened beverages. The result has been an explosion in the obesity rate from 14.5% in 1971 to 30.9% in 2000. Obviously, standard nutritional advice has had little impact against the onslaught of energy-dense, fast-food meals. To compound the problem, agricultural policies in the United States and Europe subsidize the costs of corn, soy, and wheat, leading to even cheaper processed foods.
Just as culpable, the world's population is experiencing a more sedentary lifestyle as jobs become less physically demanding. The increased use of mechanized transportation and labor-saving devices has been a boon to economic development but bad news for the population's health. Worldwide, people continue to enjoy recreational activities that require less and less physical exertion. In particular, television viewing and video games have both been linked to the increased rate of childhood obesity.
Like most medical conditions, obesity is influenced by both environmental factors and genetics. Variations in the genes controlling metabolism and appetite can predispose individuals to becoming overweight. Furthermore, genes affect an individual's body size and composition. These genes are passed down from one generation to the next. Studies that focus on inheritance patterns determined that the offspring of two obese parents were eight times more likely to become obese than the offspring of two normal parents.
Social determinants also play a role in the prevalence of obesity. Amongst richer, industrialized countries, studies show a correlation between high BMIs and lower income classes. Attitudes toward body mass and nutrition awareness also affects a person's likelihood of becoming overweight. BMI changes over time correlate amongst friends, coworkers, and family. Also, obese people are more likely to underestimate their daily food consumption than are normal-weight people.
The complicated interplay between diet, exercise, genetics, and social influences impact an individual's weight and health. Recent obesity research shows that weight can also be influenced by viruses and gut flora. However, a person's weight is not a fateful concoction of various influences beyond his / her control. Proper weight loss and management is achievable with the correct education and taking action to establish healthy habits, like a smart diet and suitable exercise.