Fat Adult fat rates have almost quadrupled in the last 25 years. Not 22% of Britons are fat and three-quarters are overweight. The number of fat tripled in 20 years. 10% of six year olds are fat, rising to 17% of 15 year olds. Becoming fat can lead to health problems, including arthritis, heart disease and diabetes What is Fat? Your 'body mass index' or BMI is a measure of, body fat based on height and weight. A BMI of: Under 20 = underweight 20 - 25 = normal 25 - 30 = overweight 30 + = fat So, according to the formula, people are classed as fat if they have a body mass index over 30. They are overweight if it is 25 - 30. Reasons to Get Fat Fat functions as energy reservoir. It is 1aid down when food is plentiful and then converted back to energy when needed. Normal levels of fat are not a problem for the body. In fact, they're necessary for it to function smoothly. On a basic level, people become fat when their caloric intake is higher than their calorie expenditure. However, a host of factors complicate this picture. An individual's genetics, metabolism, culture and lifestyle. all have a role to play. Where is Fat Stored in the Body? Most fat is stored under the skin. But there is also some on top of your kidneys and inside your liver and muscles. Other body parts that gather fat depend on your gender: •adult men: chest, waist •adult women: breasts, waist and hips Fat tissue is made up of fat cells. These are like tiny plastic bags that hold droplets of fat. Fat cells are only formed in our childhood. They start growing while we are in our mothers' pregnancy. The next stage of generation is during puberty (青春期), when the sex hormones are triggered. It defines the areas in which the fat cells grow. The amount of fat the body wants to store is thought to be proportional to the total number of fat cells. After puberty, we do not grow any more fat cells. Our ceils just expand or shrink to accommodate the fat inside our bodies. The problem with Childhood Fat If a child becomes fat their body processes can change. Some of these may Be difficult or even impossible to alter in adulthood. Fat ceils are laid down in the first few years of life. If fat is stored quickly, more fat cells are created. So a fat child can have up to three times as many as a normal child. Eventually, fat cells stop multiplying and an adult has a fixed number for the rest of their life. The existing cells simply enlarge or shrink to accommodate more fat. Health problems for kids — Few health problems are observed in obsess children. But they may develop conditions that cause problems later in life, such as high blood pressure. They may also suffer from 'sleep apnoea (呼吸暂停)'. When this happens, soft tissue in the throat blocks the airways during sleep. This can stop their breathing for up to a minute. This process can happen hundreds of times a night, leading to heart disease, memory problems, headaches and fatigue. Diabetes risk Some fat children may develop type Ⅱ diabetes. Normally this condition only starts much later in life. When it strikes, the body stops being able to process sugar properly and the cells are starved of energy. Type Ⅱ diabetes cannot be cured, but it can be treated. It may lead to complications such as nerve damage, heart disease, kidney disease and blindness. Children with this condition will have to live with it all their lives, increasing the chance of complications. What Treatments Are Available? New drugs — Current weigh-loss drugs are mainly amphetamine (安非他明，一种药品) based. They increase the amount of some hormones in the blood, lowering hunger levels. However, they are not s