Prenatal effects. Your chances of becoming fat may be set before you are even born. Children of obese mothers - especially those who develop gestational diabetes - are much more likely to become obese themselves. While this may be partly down to genetics, there is also some ‘intrauterine programming. Offspring of mice fed a high-fat diet during pregnancy are much more likely to become fat than the offspring of identical mice fed a normal diet. Intriguingly, the effect persists for two or three generations.

Air conditioning-Air conditioning keeps us in a temperature range in which we do not have to regulate our body heat. Scientists suggest that when people are out of this zone we lose weight. If it's too cold we burn fat to stay warm, and if it's too hot our appetites decrease. Studies show that people are keeping their houses warmer in the winter and cooler in the summer than they did in years past, so these natural influences on weight are negated.

Weight and Genetics-Although genetic influences do have a significant influence on body weight; human genes do not change in the space of a few decades! Therefore the huge rise in obesity among all population groups, especially in America, cannot be accounted for by genetic influence or interference.

Alcohol -- So you work hard, and your day is full of stress and pressure. When it's over, all you want to do is to sit down, relax, and have a drink or two to "take the edge off." Sound familiar? Millions of people rely on that glass of wine, a gin and tonic, or a martini to feel better at the end of the day. The average drink has approximately 150 calories, and if you happen to be partial to mixed or exotic drinks--like daiquiris, mojitos, cosmopolitans or other tasty libations--the calorie count is substantially higher. Two average drinks can cost you 300 calories a day or 2,100 calories a week. So drinking regularly can yield over 2 pounds per month and 24 pounds per year.

Lack of Physical Activity-The number one reason people give for not exercising is time. We can't find time to exercise; yet the average person watches television for 4½ hours every day. It has been proven that small amounts of physical activity can have a big impact on your weight and your health. There are very inexpensive "low-sweat" solutions for increasing your physical activity that you can perform in as few as 10 to 15 minutes a day-while watching television. Little moves can create big results.

Bad eating habits are the top reason why people become obese. With neither the time, nor the inclination to control one’s meals, there’s no wonder people get fat all over the world. People are always busy, but this is not the excuse that we have to eat junk food all the time. Fast foods may look good, but they contain too high fat for your body. Thing is, a single burger is worth a whole meal, but your body does not judge the situation this way. Your stomach will never be filled by a regular burger, so it will keep asking for more, despite the fact that your body does not need more burgers.