State of the World 2000, published by World watch Institute, reports that the number of people who are overfed and undernourished (a staggering 1.2 billion) now equals the number of those who are starving from from lack of food. 

Obese people are at greater risk for serious conditions like diabetes and heart disease—not to mention the social stigma associated with being larger than their peers.
While most people believe that they gain weight due to heredity, eating too much, or because of aging, the major reasons people gain weight include:

• High Fructose Corn Syrup - Obesity in America is at epidemic proportions, with 75% of the population expected to be overweight by 2015.  Studies have shown that the obesity rates in the US exactly follow the trend and time line of the introduction of High Fructose Corn Syrup (HFCS) into our diet. Between 1970 and 1990 consumption increased by more than 1000% mostly due to the sot drink manufaturers switching to HFCS as their sweetnener.    A 2004 report showed that Americans eat 132 calories of HFCS every day with the figure closer to 300 calories for the top 20 of people.  
  
  HFCS is chemically altered corn starch that is in just about everything we eat.  It is added to food for two reasons: one, to lower the cost, and the other to bulk up the food so the consumer thinks he is getting more for his money.  However, the body doesn't recognize chemically altered products and either flushes them out of the body or stores them as fat.  HFCS also blocks the absorption of nutrients from the food it is in.  HFCS is banned in Great Britain and is soon to be banned in Europe. 
  
  Unlike other carbohydrates, the main sweetener in beverages — high-fructose corn syrup — does not spur production of insulin to make the body "process" calories. It also does not spur leptin, a substance that helps moderate appetite. For these reasons, beverages are not as satisfying as foods containing similar amounts of calories and fly under the radar of the body's normal weight-regulating mechanisms.  According to New York University biologist Marion Nestle, an expert on nutrition and food policy, "If I were advising someone to lose weight, I'd start with soft drinks and juice drinks. Get rid of them."   The reason behind that recommendation is soft drinks and juice drinks contain HFCS.   Dr. Terrill Bravender concurs.  According to Dr. Bravender, pediatric obesity specialist at Duke University, Durham, NC, "The average person gets 10% of their total calories from sugared beverages, with 7.5 % from sodas. By cutting out sodas, the average person would lose two pounds a month."
   
• Nutrient deficiency - Most people eat too much cooked, processed and nutrient deficient food.  In fact, we Americans are the most overfed and under-nourished people in the world!  According to one pharmacist, "I see a lot of overweight people who are all malnourished".  When you eat nutrient-deficient food, your stomach may be full, but your body continues to send out the 'I'm hungry' signal.   This leads to overeating and weight gain. 
  
  
• Changes in body composition - As people age, they gradually lose lean muscle mass and develop more fat, a process known as sarcopenia.   Poor food choices and lack of exercise can accelerate this condition. This is significant because it takes between 25 and 50 calories per day to maintain a pound of lean muscle, whereas it only takes whereas it only takes 2 calories per day to maintain a pound of fat. Over time, this means that the body processes fewer and fewer calories, which in turn leads to weight gain.

According to their BMIs, two-thirds of adult American women fall into the overweight or obese category.   A 2007 report from the Centers for Disease Control found that the prevalence of obesity among U.S. adults doubled between 1980 and 2004. Compared to women of a generation ago, we're 24 pounds heavier on average, and there's been an especially alarming increase in those at the upper end of the scale (not just obese, defined as a BMI of 30 or higher, but significantly obese, with a BMI above 35).  High BMIs are associated with increased risk of diabetes, high blood pressure, some cancers and heart problems.   According to Nancy Snyderman, MD, medical consultant for NBC, more people will die from obesity by mid century than from all cancers combined.

Dr. Walter C. Willett of the Harvard School of Public Health, stated at the annual meeting of the American Association for the Advancement of Science,being obese is currently associated with about 14 percent of cancer deaths in men and 20 percent in women, compared with about 30 percent each for smoking. He continued saying research is producing increasing evidence associating obesity with a variety of cancers, including breast, colorectal, liver, pancreas and gallbladder.  

Recently researchers analyzed a variety of published medical reports on obesity from 1980 to 2005 plus World Health Organization data, and concluded that the prevalence of childhood obesity increased in almost all the countries for which data was available; a trend fueled by among other factors, more sedentary lives and the increasing availability of junk food.

According to Dr. Richard, Carmona, former US surgeon general and currently chairing the Strategies to Overcome and Prevent Obesity Alliance, "the rise in childhood obesity coincides with the rise in related conditions such as type 2 diabetes and high blood pressure".  He continued, "these are middle aged diseases, and we are seeing them in elementary children".
 
The public health consequences of the trend alarm experts, says Dr. Phillip Thomas, a surgeon who works with obese patients.  Because obese children tend to carry the problem into adulthood, Thomas and other doctors say they will be sicker as they get older, suffering from degenerative diseases such as heart disease, stroke, and other ailments stemming from their weight.   Dr. Thomas continued, "This is going to be the first generation that's going to have a shorter life expectancy than their parents".